Rcat domain found in RING finger protein 14 (RNF14); RNF14, also called androgen receptor (AR)-associated protein 54 (ARA54), HFB30, or Triad2 protein, is an RBR-type E3 ubiquitin-protein ligase that is highly expressed in the testis and interacts with class III E2s (UBE2E2, UbcH6, and UBE2E3). Its differential localization may play an important role in testicular development and spermatogenesis in humans. RNF14 functions as a transcriptional regulator of mitochondrial and immune function in muscles. It is a ligand-dependent AR co-activator that enhances AR-dependent transcriptional activation. It also may participate in enhancing cell cycle progression and cell proliferation via induction of cyclin D1. Moreover, RNF14 is crucial for colon cancer cell survival. It acts as a new enhancer of the Wnt-dependent transcriptional outputs that acts at the level of the T-cell factor/lymphoid enhancer factor (TCF/LEF)-beta-catenin complex. RNF14 contains an N-terminal RWD domain, and a C-terminal RBR domain. The RBR domain was previously known as RING-BetweenRING-RING domain or TRIAD [two RING fingers and a DRIL (double RING finger linked)] domain. Based on current understanding of the structural biology of RBR ligases, the nomenclature of RBR has been changed to RING1-BRcat (benign-catalytic)-Rcat (required-for-catalysis) recently. The RBR domain uses an auto-inhibitory mechanism to modulate ubiquitination activity, as well as a hybrid mechanism that combines aspects from both RING and HECT E3 ligase functions to facilitate the ubiquitination reaction. This model corresponds to the Rcat domain of RNF14 that is essential for RBR E3 ligase activity and adopts the same fold as the BRcat domain.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 1358101708 390 EEMESKDWLEKNSKSCPCCGTPIQKLDGCNKMTCTGCMQYFCWICMGSLSRANPYRHFTDSESPCFNR 457
Cdd:cd20354     1 EEKLSEEWLEKNSKPCPGCGTLIEKIDGCNKMTCTKCRTYFCWLCLKVLSRTNPYSHFSDPNSPCFNR 68

RING finger, HC subclass, found in RING finger protein 14 (RNF14) and similar proteins; RNF14, also known as androgen receptor-associated protein 54 (ARA54), HFB30, or Triad2 protein, is an RBR-type E3 ubiquitin-protein ligase that is highly expressed in the testis and interacts with class III E2s (UBE2E2, UbcH6, and UBE2E3). Its differential localization may play an important role in testicular development and spermatogenesis in humans. RNF14 functions as a transcriptional regulator of mitochondrial and immune function in muscle. It is a ligand-dependent androgen receptor (AR) co-activator and may also may participate in enhancing cell cycle progression and cell proliferation via induction of cyclin D1. Moreover, RNF14 is crucial for colon cancer cell survival. It acts as a new enhancer of the Wnt-dependent transcriptional outputs that acts at the level of the T-cell factor/lymphoid enhancer factor (TCF/LEF)-beta-catenin complex. RNF14 contains an N-terminal RWD domain and a C-terminal RBR domain. The RBR domain was previously known as RING-BetweenRING-RING domain or TRIAD [two RING fingers and a DRIL (double RING finger linked)] domain. Based on current understanding of the structural biology of RBR ligases, the nomenclature of RBR has been corrected as RING-BRcat (benign-catalytic)-Rcat (required-for-catalysis) recently. The RBR (RING1-BRcat-Rcat) domain uses an auto-inhibitory mechanism to modulate ubiquitination activity, as well as a hybrid mechanism that combines aspects from both RING and HECT E3 ligase function to facilitate the ubiquitination reaction. This model corresponds to the RING domain, a C3HC4-type RING-HC finger required for RBR-mediated ubiquitination.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*....
gi 1358101708 214 FNSKLFLCSICFCEKLGSDCMYFLECKHVYCKACLKDYFEIQIKDGQVKCLNCPEPQCP 272
Cdd:cd16628     1 FNSKIFTCNICFLDKLGSECMYFKDCGHVYCKECLKEYFEVQIRDGNVTSLNCPEPKCA 59

Rcat domain found in RING finger protein 14 (RNF14); RNF14, also called androgen receptor (AR)-associated protein 54 (ARA54), HFB30, or Triad2 protein, is an RBR-type E3 ubiquitin-protein ligase that is highly expressed in the testis and interacts with class III E2s (UBE2E2, UbcH6, and UBE2E3). Its differential localization may play an important role in testicular development and spermatogenesis in humans. RNF14 functions as a transcriptional regulator of mitochondrial and immune function in muscles. It is a ligand-dependent AR co-activator that enhances AR-dependent transcriptional activation. It also may participate in enhancing cell cycle progression and cell proliferation via induction of cyclin D1. Moreover, RNF14 is crucial for colon cancer cell survival. It acts as a new enhancer of the Wnt-dependent transcriptional outputs that acts at the level of the T-cell factor/lymphoid enhancer factor (TCF/LEF)-beta-catenin complex. RNF14 contains an N-terminal RWD domain, and a C-terminal RBR domain. The RBR domain was previously known as RING-BetweenRING-RING domain or TRIAD [two RING fingers and a DRIL (double RING finger linked)] domain. Based on current understanding of the structural biology of RBR ligases, the nomenclature of RBR has been changed to RING1-BRcat (benign-catalytic)-Rcat (required-for-catalysis) recently. The RBR domain uses an auto-inhibitory mechanism to modulate ubiquitination activity, as well as a hybrid mechanism that combines aspects from both RING and HECT E3 ligase functions to facilitate the ubiquitination reaction. This model corresponds to the Rcat domain of RNF14 that is essential for RBR E3 ligase activity and adopts the same fold as the BRcat domain.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 1358101708 390 EEMESKDWLEKNSKSCPCCGTPIQKLDGCNKMTCTGCMQYFCWICMGSLSRANPYRHFTDSESPCFNR 457
Cdd:cd20354     1 EEKLSEEWLEKNSKPCPGCGTLIEKIDGCNKMTCTKCRTYFCWLCLKVLSRTNPYSHFSDPNSPCFNR 68

RING finger, HC subclass, found in RING finger protein 14 (RNF14) and similar proteins; RNF14, also known as androgen receptor-associated protein 54 (ARA54), HFB30, or Triad2 protein, is an RBR-type E3 ubiquitin-protein ligase that is highly expressed in the testis and interacts with class III E2s (UBE2E2, UbcH6, and UBE2E3). Its differential localization may play an important role in testicular development and spermatogenesis in humans. RNF14 functions as a transcriptional regulator of mitochondrial and immune function in muscle. It is a ligand-dependent androgen receptor (AR) co-activator and may also may participate in enhancing cell cycle progression and cell proliferation via induction of cyclin D1. Moreover, RNF14 is crucial for colon cancer cell survival. It acts as a new enhancer of the Wnt-dependent transcriptional outputs that acts at the level of the T-cell factor/lymphoid enhancer factor (TCF/LEF)-beta-catenin complex. RNF14 contains an N-terminal RWD domain and a C-terminal RBR domain. The RBR domain was previously known as RING-BetweenRING-RING domain or TRIAD [two RING fingers and a DRIL (double RING finger linked)] domain. Based on current understanding of the structural biology of RBR ligases, the nomenclature of RBR has been corrected as RING-BRcat (benign-catalytic)-Rcat (required-for-catalysis) recently. The RBR (RING1-BRcat-Rcat) domain uses an auto-inhibitory mechanism to modulate ubiquitination activity, as well as a hybrid mechanism that combines aspects from both RING and HECT E3 ligase function to facilitate the ubiquitination reaction. This model corresponds to the RING domain, a C3HC4-type RING-HC finger required for RBR-mediated ubiquitination.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*....
gi 1358101708 214 FNSKLFLCSICFCEKLGSDCMYFLECKHVYCKACLKDYFEIQIKDGQVKCLNCPEPQCP 272
Cdd:cd16628     1 FNSKIFTCNICFLDKLGSECMYFKDCGHVYCKECLKEYFEVQIRDGNVTSLNCPEPKCA 59

RWD domain; This domain was identified in WD40 repeat proteins and Ring finger domain proteins. The function of this domain is unknown. GCN2 is the alpha-subunit of the only translation initiation factor (eIF2 alpha) kinase that appears in all eukaryotes. Its function requires an interaction with GCN1 via the domain at its N-terminus, which is termed the RWD domain after three major RWD-containing proteins: RING finger-containing proteins, WD-repeat-containing proteins, and yeast DEAD (DEXD)-like helicases. The structure forms an alpha + beta sandwich fold consisting of two layers: a four-stranded antiparallel beta-sheet, and three side-by-side alpha-helices.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1358101708   7 EAQEDELLALASIYDADEFRKAESVqggetriYLDLPQNFKIFVSGNSNESlqnsgfeytiCFLPPLVLNFEL------- 79
Cdd:pfam05773   1 EEQEEELEALESIYPDEFEVISDSP-------YESLEIEIKLSLDSDESDS----------SHLPPLVLKFTLpedypde 63

                          90       100       110       120       130
                  ....*....|....*....|....*....|....*....|....*....|....*..
gi 1358101708  80 --PpdypsssppsFTLSGKW-LSPTQLSALCKHLDNLWEEHRGRVVLFAWMQFLKEE 133
Cdd:pfam05773  64 ppK----------ISLSSPWnLSDEQVLSLLEELEELAEENLGEVMIFELIEWLQEN 110

In Between Ring fingers; the domains occurs between pairs og RING fingers

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....
gi 1358101708  290 ARYDRLLLQSTLDLMADVVYCPRP-CCQLPVMQEP-GGTMAICSSCNFAFCTLCRLTYHGLSPC 351
Cdd:smart00647   1 EKYERLLLESYVESNPDLKWCPAPdCSAAIIVTEEeGCNRVTCPKCGFSFCFRCKVPWHSPVSC 64

zinc-RING finger domain;

                          10        20        30
                  ....*....|....*....|....*....|....*.
gi 1358101708 221 CSICFCEKLGSDCMYFLECKHVYCKACLKDYFEIQI 256
Cdd:pfam14634   2 CNKCFKELSKTRPFYLTSCGHIFCEECLTRLLQERQ 37

Rcat domain found in RING finger protein 14 (RNF14); RNF14, also called androgen receptor (AR)-associated protein 54 (ARA54), HFB30, or Triad2 protein, is an RBR-type E3 ubiquitin-protein ligase that is highly expressed in the testis and interacts with class III E2s (UBE2E2, UbcH6, and UBE2E3). Its differential localization may play an important role in testicular development and spermatogenesis in humans. RNF14 functions as a transcriptional regulator of mitochondrial and immune function in muscles. It is a ligand-dependent AR co-activator that enhances AR-dependent transcriptional activation. It also may participate in enhancing cell cycle progression and cell proliferation via induction of cyclin D1. Moreover, RNF14 is crucial for colon cancer cell survival. It acts as a new enhancer of the Wnt-dependent transcriptional outputs that acts at the level of the T-cell factor/lymphoid enhancer factor (TCF/LEF)-beta-catenin complex. RNF14 contains an N-terminal RWD domain, and a C-terminal RBR domain. The RBR domain was previously known as RING-BetweenRING-RING domain or TRIAD [two RING fingers and a DRIL (double RING finger linked)] domain. Based on current understanding of the structural biology of RBR ligases, the nomenclature of RBR has been changed to RING1-BRcat (benign-catalytic)-Rcat (required-for-catalysis) recently. The RBR domain uses an auto-inhibitory mechanism to modulate ubiquitination activity, as well as a hybrid mechanism that combines aspects from both RING and HECT E3 ligase functions to facilitate the ubiquitination reaction. This model corresponds to the Rcat domain of RNF14 that is essential for RBR E3 ligase activity and adopts the same fold as the BRcat domain.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 1358101708 390 EEMESKDWLEKNSKSCPCCGTPIQKLDGCNKMTCTGCMQYFCWICMGSLSRANPYRHFTDSESPCFNR 457
Cdd:cd20354     1 EEKLSEEWLEKNSKPCPGCGTLIEKIDGCNKMTCTKCRTYFCWLCLKVLSRTNPYSHFSDPNSPCFNR 68

RING finger, HC subclass, found in RING finger protein 14 (RNF14) and similar proteins; RNF14, also known as androgen receptor-associated protein 54 (ARA54), HFB30, or Triad2 protein, is an RBR-type E3 ubiquitin-protein ligase that is highly expressed in the testis and interacts with class III E2s (UBE2E2, UbcH6, and UBE2E3). Its differential localization may play an important role in testicular development and spermatogenesis in humans. RNF14 functions as a transcriptional regulator of mitochondrial and immune function in muscle. It is a ligand-dependent androgen receptor (AR) co-activator and may also may participate in enhancing cell cycle progression and cell proliferation via induction of cyclin D1. Moreover, RNF14 is crucial for colon cancer cell survival. It acts as a new enhancer of the Wnt-dependent transcriptional outputs that acts at the level of the T-cell factor/lymphoid enhancer factor (TCF/LEF)-beta-catenin complex. RNF14 contains an N-terminal RWD domain and a C-terminal RBR domain. The RBR domain was previously known as RING-BetweenRING-RING domain or TRIAD [two RING fingers and a DRIL (double RING finger linked)] domain. Based on current understanding of the structural biology of RBR ligases, the nomenclature of RBR has been corrected as RING-BRcat (benign-catalytic)-Rcat (required-for-catalysis) recently. The RBR (RING1-BRcat-Rcat) domain uses an auto-inhibitory mechanism to modulate ubiquitination activity, as well as a hybrid mechanism that combines aspects from both RING and HECT E3 ligase function to facilitate the ubiquitination reaction. This model corresponds to the RING domain, a C3HC4-type RING-HC finger required for RBR-mediated ubiquitination.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*....
gi 1358101708 214 FNSKLFLCSICFCEKLGSDCMYFLECKHVYCKACLKDYFEIQIKDGQVKCLNCPEPQCP 272
Cdd:cd16628     1 FNSKIFTCNICFLDKLGSECMYFKDCGHVYCKECLKEYFEVQIRDGNVTSLNCPEPKCA 59

RWD domain of protein IMPACT and related proteins; IMPACT, also imprinted and ancient gene protein homolog, acts as a translational regulator that ensures constant high levels of translation upon a variety of stress conditions, such as amino acid starvation, UV-C irradiation, proteasome inhibitor treatment, and glucose deprivation. It plays a role as a negative regulator of EIF2AK4/GCN2 kinase activity. It impairs GCN1-mediated EIF2AK4/GCN2 activation, and hence EIF2AK4/GCN2-mediated eIF-2-alpha phosphorylation and subsequent down-regulation of protein synthesis. IMPACT may be required to regulate translation in specific neuronal cells under amino acid starvation conditions by preventing GCN2 activation and therefore ATF4 synthesis. Through its inhibitory action on EIF2AK4/GCN2, IMPACT plays a role in differentiation of neuronal cells by stimulating neurite outgrowth.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1358101708  10 EDELLALASIYdADEFRkaesVQGGETRIYLdlpqnFKIFVSGnsneslqnsgfeytiCFLPPLVLNFELPPDYPSSSPP 89
Cdd:cd23821     1 AEEIEALEAIY-GEDFV----VIDESARSFV-----IRIELDG---------------PHLPPLVLRVHLPPDYPSHSPP 55

                          90       100       110       120
                  ....*....|....*....|....*....|....*....|....*.
gi 1358101708  90 SFTLSGKWLSPTQLSALCKHLDNLWEEHRGRVVLFAWMQFLKEETL 135
Cdd:cd23821    56 IFELSAPWLSGEERSELCAELDEIWEENAGEPVLFQWVEWLREYLL 101

Rcat domain found in ankyrin repeat and IBR domain-containing protein 1 (ANKIB1) and similar proteins; ANKIB1 is an RBR-type E3 ubiquitin-protein ligase that may function as part of an E3 complex, which accepts ubiquitin from specific E2 ubiquitin-conjugating enzymes and then transfers it to substrates. It contains N-terminal ankyrin repeats, and an RBR domain that was previously known as RING-BetweenRING-RING domain or TRIAD [two RING fingers and a DRIL (double RING finger linked)] domain. Based on current understanding of the structural biology of RBR ligases, the nomenclature of RBR has been changed to RING1-BRcat (benign-catalytic)-Rcat (required-for-catalysis) recently. The RBR domain uses an auto-inhibitory mechanism to modulate ubiquitination activity, as well as a hybrid mechanism that combines aspects from both RING and HECT E3 ligase functions to facilitate the ubiquitination reaction. This model corresponds to the Rcat domain of ANKIB1 that is essential for RBR E3 ligase activity and adopts the same fold as the BRcat domain.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*..
gi 1358101708 397 WLEKNSKSCPCCGTPIQKLDGCNKMTCTGCMQYFCWICMGSLSRANP 443
Cdd:cd20361     4 WLVTNSKPCPNCKSPIQKNEGCNHMKCSKCKYDFCWVCLEEWKKHSS 50

domain in RING finger and WD repeat containing proteins and DEXDc-like helicases subfamily related to the UBCc domain;

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1358101708   12 ELLALASIYDADEFRKAESVQGGETRIYLDLPQNfkifvsgnsneslqnsgfeYTICFLPPLVLNFELPPDYPSSSPPSF 91
Cdd:smart00591   1 ELEALESIYPEDFEVIDEDARIPEITIKLSPSSD-------------------EGEDQYVSLTLQVKLPENYPDEAPPIS 61

                           90       100       110       120
                   ....*....|....*....|....*....|....*....|....*.
gi 1358101708   92 TLSGKWLSPTQLSALCKHLDNLWEEHRGRVVLFAWMQFLKEETLTY 137
Cdd:smart00591  62 LLNSEGLSDEQLAELLKKLEEIAEENLGEVMIFELVEKLQEFLSEF 107

RING finger, HC subclass, found in Saccharomyces cerevisiae translation termination inhibitor protein ITT1 and similar proteins; ITT1 is a protein that modulates the efficiency of translation termination, resulting in the readthrough of all three types of nonsense codons UAA, UAG and UGA. ITT1 contains a typical C3HC4-type RING-HC finger.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1358101708 218 LFLCSICFCEKLGSDCmYFLECKHVYCKACLKDYFEIQIKDGQVKCLNCPEPQC 271
Cdd:cd23134     4 SYHCGICFEEKKGSDF-IKLPCGHVFCRECLQDYYTIHIQEGEVSSVKCPDPNC 56

Rcat domain found in two RING fingers and DRIL [double RING finger linked] 1 (TRIAD1); TRIAD1, also called ariadne-2 (ARI-2), protein ariadne-2 homolog, Ariadne RBR E3 ubiquitin protein ligase 2 (ARIH2), or UbcM4-interacting protein 48, is an RBR-type E3 ubiquitin-protein ligase that catalyzes the formation of polyubiquitin chains linked via lysine-48 as well as lysine-63 residues. Its auto-ubiquitylation can be catalyzed by the E2 conjugating enzyme UBCH7. TRIAD1 has been implicated in hematopoiesis, specifically in myelopoiesis, as well as in embryogenesis. It functions as a regulator of endosomal transport, and is required for the proper function of multivesicular bodies. It also acts as a novel ubiquitination target for proteasome-dependent degradation by murine double minute 2 (MDM2). As a proapoptotic protein, TRIAD1 promotes p53 activation, and inhibits MDM2-mediated p53 ubiquitination and degradation. Furthermore, TRIAD1 can inhibit the ubiquitination and proteasomal degradation of growth factor independence 1 (Gfi1), a transcriptional repressor essential for the function and development of many different hematopoietic lineages. TRIAD1 contains an RBR domain that was previously known as RING-BetweenRING-RING domain or TRIAD [two RING fingers and a DRIL (double RING finger linked)] domain. Based on current understanding of the structural biology of RBR ligases, the nomenclature of RBR has been changed to RING1-BRcat (benign-catalytic)-Rcat (required-for-catalysis) recently. The RBR domain uses an auto-inhibitory mechanism to modulate ubiquitination activity, as well as a hybrid mechanism that combines aspects from both RING and HECT E3 ligase functions to facilitate the ubiquitination reaction. This model corresponds to the Rcat domain of TRIAD1 that is essential for RBR E3 ligase activity and adopts the same fold as the BRcat domain.

                          10        20        30
                  ....*....|....*....|....*....|....*..
gi 1358101708 401 NSKSCPCCGTPIQKLDGCNKMTCTGCMQYFCWICMGS 437
Cdd:cd20360     2 HTKDCPKCHVCIEKNGGCNHMQCSKCKHEFCWMCLGD 38

Rcat domain found in the RNF144 protein subfamily; The RNF144 subfamily includes RNF144A and RNF144B, which are transmembrane (TM) domain-containing RBR-type E3 ubiquitin-protein ligases. RNF144A, also called UbcM4-interacting protein 4 (UIP4), or ubiquitin-conjugating enzyme 7-interacting protein 4, targets DNA-dependent protein kinase catalytic subunit (DNA-PKcs), and thus promotes DNA damage-induced cell apoptosis. It is transcriptionally repressed by metastasis-associated protein 1 (MTA1) and inhibits MTA1-driven cancer cell migration and invasion. RNF144B, also called PIR2, IBR domain-containing protein 2 (IBRDC2), or p53-inducible RING finger protein (p53RFP), induces p53-dependent but caspase-independent apoptosis. It interacts with E2 ubiquitin-conjugating enzymes UbcH7 and UbcH8, but not with UbcH5. It is involved in ubiquitination and degradation of p21, a p53 downstream protein promoting growth arrest and antagonizing apoptosis, suggesting a role in switching a cell from p53-mediated growth arrest to apoptosis. Moreover, RNF144B regulates the levels of Bax, a pro-apoptotic protein from the Bcl-2 family, and protects cells from unprompted Bax activation and cell death. It also regulates epithelial homeostasis by mediating degradation of p21WAF1 and p63. Both RNF144A and RNF144B contain an RBR domain followed by a potential single-TM domain. The RBR domain was previously known as RING-BetweenRING-RING domain or TRIAD [two RING fingers and a DRIL (double RING finger linked)] domain. Based on current understanding of the structural biology of RBR ligases, the nomenclature of RBR has been changed to RING1-BRcat (benign-catalytic)-Rcat (required-for-catalysis) recently. The RBR domain uses an auto-inhibitory mechanism to modulate ubiquitination activity, as well as a hybrid mechanism that combines aspects from both RING and HECT E3 ligase functions to facilitate the ubiquitination reaction. This model corresponds to the Rcat domain of the RNF144 protein subfamily that is essential for RBR E3 ligase activity and adopts the same fold as the BRcat domain.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*....
gi 1358101708 403 KSCPCCGTPIQKLDGCNKMTCTGCMQYFCWICMGSLSRANPYRHFTDseSPCFNRLFHA 461
Cdd:cd20352     6 KRCPMCHVPIERDEGCAQMMCKNCKHVFCWYCLASLDDDFLLRHYDK--GPCKNKLGHS 62

Rcat domain found in E3 ubiquitin-protein ligase ARI1 and similar proteins; This subfamily contains probable RBR-type E3 ubiquitin-protein ligases (EC 2.3.2.31) including Arabidopsis thaliana ARI1, ARI2, and ARI3. They may function as part of E3 complexes, which accept ubiquitin from E2 ubiquitin-conjugating enzymes and then transfer it to substrates. Members of this subfamily contain an RBR domain that was previously known as RING-BetweenRING-RING domain or TRIAD [two RING fingers and a DRIL (double RING finger linked)] domain. Based on current understanding of the structural biology of RBR ligases, the nomenclature of RBR has been changed to RING1-BRcat (benign-catalytic)-Rcat (required-for-catalysis) recently. The RBR domain uses an auto-inhibitory mechanism to modulate ubiquitination activity, as well as a hybrid mechanism that combines aspects from both RING and HECT E3 ligase functions to facilitate the ubiquitination reaction. This model corresponds to the Rcat domain of ARI1-like proteins that are essential for RBR E3 ligase activity and adopt the same fold as the BRcat domain.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*.
gi 1358101708 401 NSKSCPCCGTPIQKLDGCNKMTCTgCMQYFCWICMGSLSRANPYRH 446
Cdd:cd22586     3 NTKLCPKCSKPVEKNGGCNLVTCR-CGQHFCWLCGAATGRDHTWES 47

Rcat domain found in E3 ubiquitin-protein ligase ARI7 and similar proteins; This subfamily contains probable RBR-type E3 ubiquitin-protein ligases (EC 2.3.2.31) including Arabidopsis thaliana ARI5, ARI6, ARI7, and ARI8, as well as Dictyostelium discoideum RbrA (also called Ariadne-like ubiquitin ligase). They may function as part of E3 complexes, which accept ubiquitin from E2 ubiquitin-conjugating enzymes and then transfer it to substrates. RbrA may be required for normal cell-type proportioning and cell sorting during multicellular development, and is also necessary for spore cell viability. Members of this subfamily contain an RBR domain that was previously known as RING-BetweenRING-RING domain or TRIAD [two RING fingers and a DRIL (double RING finger linked)] domain. Based on current understanding of the structural biology of RBR ligases, the nomenclature of RBR has been changed to RING1-BRcat (benign-catalytic)-Rcat (required-for-catalysis) recently. The RBR domain uses an auto-inhibitory mechanism to modulate ubiquitination activity, as well as a hybrid mechanism that combines aspects from both RING and HECT E3 ligase functions to facilitate the ubiquitination reaction. This model corresponds to the Rcat domain of ARI7-like proteins that are essential for RBR E3 ligase activity and adopt the same fold as the BRcat domain.

                          10        20        30
                  ....*....|....*....|....*....|....*..
gi 1358101708 401 NSKSCPCCGTPIQKLDGCNKMTCTG-CMQYFCWICMG 436
Cdd:cd22583     1 NTKPCPKCKRPIEKNQGCMHMTCSPpCKHEFCWLCLG 37

Rcat domain found in RING finger protein 144B (RNF144B); RNF144B, also called PIR2, IBR domain-containing protein 2 (IBRDC2), or p53-inducible RING finger protein (p53RFP), is a transmembrane (TM) domain-containing RBR E3 ubiquitin-protein ligase that induces p53-dependent but caspase-independent apoptosis. It interacts with E2 ubiquitin-conjugating enzymes UbcH7 and UbcH8, but not with UbcH5. It is involved in ubiquitination and degradation of p21, a p53 downstream protein promoting growth arrest and antagonizing apoptosis, suggesting a role in switching a cell from p53-mediated growth arrest to apoptosis. Moreover, RNF144B regulates the levels of Bax, a pro-apoptotic protein from the Bcl-2 family, and protects cells from unprompted Bax activation and cell death. It also regulates epithelial homeostasis by mediating degradation of p21WAF1 and p63. RNF144B contains an RBR domain followed by a potential single-TM domain. The RBR domain was previously known as RING-BetweenRING-RING domain or TRIAD [two RING fingers and a DRIL (double RING finger linked)] domain. Based on current understanding of the structural biology of RBR ligases, the nomenclature of RBR has been changed to RING1-BRcat (benign-catalytic)-Rcat (required-for-catalysis) recently. The RBR domain uses an auto-inhibitory mechanism to modulate ubiquitination activity, as well as a hybrid mechanism that combines aspects from both RING and HECT E3 ligase functions to facilitate the ubiquitination reaction. This model corresponds to the Rcat domain of RNF144B that is essential for RBR E3 ligase activity and adopts the same fold as the BRcat domain.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*....
gi 1358101708 403 KSCPCCGTPIQKLDGCNKMTCTGCMQYFCWICMGSLSRANPYRHFtdSESPCFNRLFHA 461
Cdd:cd20369     7 KQCPVCRVYIERNEGCAQMMCKNCKHTFCWYCLQNLDNDIFLRHY--DKGPCRNKLGHS 63

Rcat domain found in cullin-9 (CUL-9) and similar proteins; CUL-9, also called UbcH7-associated protein 1 (H7-AP1), p53-associated parkin-like cytoplasmic protein, or PARC, is a cytoplasmic RBR-type E3 ubiquitin-protein ligase that function as a tumor suppressor and promotes p53-dependent apoptosis. It mediates the ubiquitination and degradation of cytosolic cytochrome c to promote survival in neurons and cancer cells. It is also a critical downstream effector of the 3M complex in the maintenance of microtubules and genome integrity. Moreover, CUL-9, together with CUL-7, forms homodimers and heterodimers, as well as some atypical cullin RING ligase complexes, which may exhibit ubiquitin ligase activity. CUL-9 contains a CPH domain (conserved in Cul7, PARC, and HERC2 proteins), a DOC (DOC1/APC10) domain, cullin homology domains linked with E3 ligase function, and a C-terminal RBR domain previously known as RING-BetweenRING-RING domain or TRIAD [two RING fingers and a DRIL (double RING finger linked)] domain. Based on current understanding of the structural biology of RBR ligases, the nomenclature of RBR has been changed to RING1-BRcat (benign-catalytic)-Rcat (required-for-catalysis) recently. The RBR domain uses an auto-inhibitory mechanism to modulate ubiquitination activity, as well as a hybrid mechanism that combines aspects from both RING and HECT E3 ligase functions to facilitate the ubiquitination reaction. This model corresponds to the Rcat domain of CUL-9 that is essential for RBR E3 ligase activity and adopts the same fold as the BRcat domain.

                          10        20        30
                  ....*....|....*....|....*....|....*.
gi 1358101708 402 SKSCPCCGTPIQKLDGCNKMTCTGCMQYFCWICMGS 437
Cdd:cd20359     7 SKRCPSCQAQIEKNEGCLHMTCAKCNHGFCWRCLKP 42

Modified RING finger, HC subclass (C4C4-type), found in RNF144 proteins; This group includes RNF144A and RNF144B, both of which are transmembrane (TM) domain-containing RBR-type E3 ubiquitin-protein ligases. RNF144A, also known as UbcM4-interacting protein 4 (UIP4) or ubiquitin-conjugating enzyme 7-interacting protein 4, targets DNA-dependent protein kinase catalytic subunit (DNA-PKcs), and thus promote DNA damage-induced cell apoptosis. It is transcriptionally repressed by metastasis-associated protein 1 (MTA1) and inhibits MTA1-driven cancer cell migration and invasion. RNF144B, also known as PIR2, IBR domain-containing protein 2 (IBRDC2), or p53-inducible RING finger protein (p53RFP), induces p53-dependent but caspase-independent apoptosis. It interacts with E2 ubiquitin-conjugating enzymes UbcH7 and UbcH8, but not with UbcH5. It is involved in ubiquitination and degradation of p21, a p53 downstream protein promoting growth arrest and antagonizing apoptosis, suggesting a role in switching a cell from p53-mediated growth arrest to apoptosis. Moreover, RNF144B regulates the levels of Bax, a pro-apoptotic protein from the Bcl-2 family, and protects cells from unprompted Bax activation and cell death. It also regulates epithelial homeostasis by mediating degradation of p21WAF1 and p63. Both RNF144A and RNF144B contain an RBR domain followed by a potential single-TM domain. The RBR domain was previously known as RING-BetweenRING-RING domain or TRIAD [two RING fingers and a DRIL (double RING finger linked)] domain. Based on current understanding of the structural biology of RBR ligases, the nomenclature of RBR has been corrected as RING-BRcat (benign-catalytic)-Rcat (required-for-catalysis) recently. The RBR (RING1-BRcat-Rcat) domain uses an auto-inhibitory mechanism to modulate ubiquitination activity, as well as a hybrid mechanism that combines aspects from both RING and HECT E3 ligase function to facilitate the ubiquitination reaction. This model corresponds to the RING domain, a C4C4-type RING finger whose overall folding is similar to that of the C3HC4-type RING-HC finger. It is required for RBR-mediated ubiquitination.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1358101708 219 FLCSICFCEKLGSDCMYFLECKHVYCKACLKDYFEIQIKDGQVKCLNCPEPQC 271
Cdd:cd16632     1 ITCKLCLEEVPLREMYTLQSCGCIFCLQCLKQYVEVLIREGNVSSITCPDAAC 53

Rcat domain found in RING finger protein 217 (RNF217); RNF217, also called IBR domain-containing protein 1 (IBRDC1), is a transmembrane (TM) domain-containing RBR-type E3 ubiquitin-protein ligase, with different splice variants, that is mainly expressed in testis and skeletal muscle. It interacts with the anti-apoptotic protein HAX1, and is adjacent to a translocation breakpoint involving ETV6 in childhood acute lymphoblastic leukemia (ALL). RNF217 contains an RBR domain followed by TMs. The RBR domain was previously known as RING-BetweenRING-RING domain or TRIAD [two RING fingers and a DRIL (double RING finger linked)] domain. Based on current understanding of the structural biology of RBR ligases, the nomenclature of RBR has been changed to RING1-BRcat (benign-catalytic)-Rcat (required-for-catalysis) recently. The RBR domain uses an auto-inhibitory mechanism to modulate ubiquitination activity, as well as a hybrid mechanism that combines aspects from both RING and HECT E3 ligase functions to facilitate the ubiquitination reaction. This model corresponds to the Rcat domain of RNF217 that is essential for RBR E3 ligase activity and adopts the same fold as the BRcat domain.

                          10        20        30
                  ....*....|....*....|....*....|....*
gi 1358101708 400 KNSKSCPCCGTPIQKLDGCNKMTCTGCMQYFCWIC 434
Cdd:cd20350     3 RNAQKCPKCKVYIQRSEGCDHMTCSQCNTNFCYRC 37

Rcat domain found in RING finger protein 216 (RNF216); RNF216, also called Triad domain-containing protein 3 (Triad3A), ubiquitin-conjugating enzyme 7-interacting protein 1, or zinc finger protein inhibiting NF-kappa-B (ZIN), is an RBR-type E3 ubiquitin-protein ligase that interacts with several components of the Toll-like receptor (TLR) signaling and promotes their proteolytic degradation. It negatively regulates the RIG-I RNA sensing pathway through Lys48-linked, ubiquitin-mediated degradation of the tumor necrosis factor receptor-associated factor 3 (TRAF3) adapter following RNA virus infection. It also controls ubiquitination and proteasomal degradation of receptor-interacting protein 1 (RIP1), a serine/threonine protein kinase that is critically involved in tumor necrosis factor receptor-1 (TNF-R1)-induced NF-kappa B activation, following disruption of Hsp90 binding. Moreover, RNF216 is involved in inflammatory diseases by strongly inhibiting autophagy in macrophages. It interacts with and ubiquitinates BECN1, a key regulator in autophagy, thereby contributing to BECN1 degradation. It regulates synaptic strength by ubiquitination of Arc, resulting in its rapid proteasomal degradation. It is also a key negative regulator of sustained 2DL4/KIR2DL4 (killer cell Ig-like receptor with two Ig-like domains and a long cytoplasmic domain 4)-mediated NF-kappaB signaling from internalized 2DL4, which functions by promoting ubiquitylation and degradation of endocytosed receptor from early endosomes. Furthermore, RNF216 interacts with human immunodeficiency virus type 1 (HIV-1) virion infectivity factor (Vif) protein, which is essential for the productive infection of primary human CD4 T lymphocytes and macrophages. Mutations in RNF216 may result in Gordon Holmes syndrome, a condition defined by hypogonadotropic hypogonadism and cerebellar ataxia, as well as in autosomal recessive Huntington-like disorder. RNF216 contains an RBR domain that was previously known as RING-BetweenRING-RING domain or TRIAD [two RING fingers and a DRIL (double RING finger linked)] domain. Based on current understanding of the structural biology of RBR ligases, the nomenclature of RBR has been changed to RING1-BRcat (benign-catalytic)-Rcat (required-for-catalysis) recently. The RBR domain uses an auto-inhibitory mechanism to modulate ubiquitination activity, as well as a hybrid mechanism that combines aspects from both RING and HECT E3 ligase functions to facilitate the ubiquitination reaction. The family corresponds to the Rcat domain of RNF216 that is essential for RBR E3 ligase activity and adopts the same fold as the BRcat domain.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|...
gi 1358101708 405 CPCCGTPIQKLDGCNKMTCtGCMQYFCWICMGSLsraNPYRHF 447
Cdd:cd20353    12 CPKCKTKFIKSEGCNKMTC-RCGAKMCYICRKPI---KGYDHF 50

RWD domain of eIF-2-alpha kinase GCN2 and related proteins; GCN2 (EC 2.7.11.1), also called eukaryotic translation initiation factor 2-alpha kinase 4 (EIF2AK4), acts as a metabolic-stress sensing protein kinase that phosphorylates the alpha subunit of eukaryotic translation initiation factor 2 (EIF2S1/eIF-2-alpha) in response to low amino acid availability. It also plays a role in modulating the adaptive immune response to yellow fever virus infection and promotes dendritic cells to initiate autophagy and antigene presentation to both CD4(+) and CD8(+) T-cells under amino acid starvation.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1358101708   7 EAQEDELLALASIYDaDEFRKAESVQGGETriyldlPQNFKIFVSGNSNESLQNSG-----FEYTICFlpPLVL-NFELp 80
Cdd:cd23823     2 EEQEEELEALQSIYG-DDFEDLSSKKAVWS------PPEFRIRLRPQEGESEENHVsvdlhVKFPPTY--PDVPpEIEL- 71

                          90       100       110       120       130
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1358101708  81 pdypsssppsftLSGKWLSPTQLSALCKHLDNLWEEHRGRVVLFAWMQFLKE 132
Cdd:cd23823    72 ------------ENVKGLSDEQLEELLKELEELAKELLGEEMIFELAEAVQE 111

BRcat (benign-catalytic) domain, part of the RBR (RING1-BRcat-Rcat) domain; The RBR family of RING-type E3 ligases are characterized by containing an RBR domain, which was previously known as RING-BetweenRING-RING domain or TRIAD [two RING fingers and a DRIL (double RING finger linked)] domain. It is composed of an extended RING domain (RING1) followed by an in-between RING (IBR) domain and the catalytic domain, which is structurally an IBR domain but is commonly designated as RING2. Based on current understanding of the structural biology of RBR ligases, the nomenclature of RBR has been changed to RING1-BRcat (benign-catalytic)-Rcat (required-for-catalysis) recently, where the IBR and RING2 domains have been renamed as BRcat and Rcat domains, respectively. The RBR domain uses an auto-inhibitory mechanism to modulate ubiquitination activity, as well as a hybrid mechanism that combines aspects from both RING and HECT E3 ligase functions to facilitate the ubiquitination reaction. The BRcat domain adopts the same fold as the Rcat domain while lacking the catalytic cysteine residue and ubiquitination activity. RBR family members play roles in protein quality control and can indirectly regulate transcription. Evidence suggests that RBR proteins are often parts of cullin-containing ubiquitin ligase complexes. The model corresponds to the BRcat domain.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1358101708 305 ADVVYCPRPCCQ--LPVMQEPGGTMAICSSCNFAFCTLCRLTYHGLSPCK 352
Cdd:cd20335     2 PNLRWCPTPDCGgvIRVEEPGDGPRVTCPSCGTSFCFKCKEEWHEGLTCE 51

Rcat domain found in an uncharacterized subfamily of RBR proteins; This subfamily contains uncharacterized members of the RBR family, including Arabidopsis thaliana mutator-like transposase and hypothetical protein At2g19610/F3P11.21. The RBR family of RING-type E3 ligases are characterized by containing a RBR domain, which was previously known as RING-BetweenRING-RING domain or TRIAD [two RING fingers and a DRIL (double RING finger linked)] domain. It is composed of an extended RING domain (RING1) followed by an in-between RING (IBR) domain and the catalytic domain, which is structurally an IBR domain but is commonly designated RING2. Based on current understanding of the structural biology of RBR ligases, the nomenclature of RBR has been corrected as RING1-BRcat (benign-catalytic)-Rcat (required-for-catalysis) recently, where the IBR and RING2 domains have been renamed as BRcat and Rcat domains, respectively. The RBR domain uses an auto-inhibitory mechanism to modulate ubiquitination activity, as well as a hybrid mechanism that combines aspects from both RING and HECT E3 ligase functions to facilitate the ubiquitination reaction. RBR family members play roles in protein quality control and can indirectly regulate transcription. Evidence suggests that RBR proteins are often parts of cullin-containing ubiquitin ligase complexes. This model corresponds to the Rcat domain that is essential for RBR E3 ligase activity and adopts the same fold as the BRcat domain.

                          10        20        30
                  ....*....|....*....|....*....|..
gi 1358101708 403 KSCPCCGTPIQKLDGCNKMTCtGCMQYFCWIC 434
Cdd:cd22584     3 RRCPQCGHMVELSEGCNHMTC-RCGYEFCYLC 33

zinc-RING finger domain;

                          10        20        30
                  ....*....|....*....|....*....|....*.
gi 1358101708 221 CSICFCEKLGSDCMYFLECKHVYCKACLKDYFEIQI 256
Cdd:pfam14634   2 CNKCFKELSKTRPFYLTSCGHIFCEECLTRLLQERQ 37

BRcat (benign-catalytic) and Rcat (required-for-catalysis) domains, part of the RBR (RING1-BRcat-Rcat) domain; The RBR family of RING-type E3 ligases are characterized by containing an RBR (RING1-BRcat-Rcat) domain, which was previously known as RING-BetweenRING-RING domain or TRIAD [two RING fingers and a DRIL (double RING finger linked)] domain. It is composed of an extended RING domain (RING1) followed by an in-between RING (IBR) domain and the catalytic domain, which is structurally an IBR domain but is commonly designated as RING2. Based on current understanding of the structural biology of RBR ligases, the nomenclature of RBRs has been changed to RING1-BRcat (benign-catalytic)-Rcat (required-for-catalysis), where the IBR and RING2 domains have been renamed as BRcat and Rcat domains, respectively. The RBR domain uses an auto-inhibitory mechanism to modulate ubiquitination activity, as well as a hybrid mechanism that combines aspects from both RING and HECT E3 ligase functions to facilitate the ubiquitination reaction. The BRcat domain adopts the same fold as the Rcat domain while lacking the catalytic cysteine residue and ubiquitination activity. RBR family members play roles in protein quality control and can indirectly regulate transcription. Evidence suggests that RBR proteins are often parts of cullin-containing ubiquitin ligase complexes.

                          10        20        30
                  ....*....|....*....|....*....|....*.
gi 1358101708 401 NSKSCPCCGTPIQKLDGCNKMTCTGCMQYFCWICMG 436
Cdd:cd14799     1 NTKWCPKCHFGFEKERGCMHATCPQCRQEFCWRCKR 36

BRcat domain found in two RING fingers and DRIL [double RING finger linked] 1 (TRIAD1); TRIAD1, also called ariadne-2 (ARI-2), protein ariadne-2 homolog, Ariadne RBR E3 ubiquitin protein ligase 2 (ARIH2), or UbcM4-interacting protein 48, is an RBR-type E3 ubiquitin-protein ligase that catalyzes the formation of polyubiquitin chains linked via lysine-48 as well as lysine-63 residues. Its auto-ubiquitylation can be catalyzed by the E2 conjugating enzyme UBCH7. TRIAD1 has been implicated in hematopoiesis, specifically in myelopoiesis, as well as in embryogenesis. It functions as a regulator of endosomal transport, and is required for the proper function of multivesicular bodies. It also acts as a novel ubiquitination target for proteasome-dependent degradation by murine double minute 2 (MDM2). As a proapoptotic protein, TRIAD1 promotes p53 activation, and inhibits MDM2-mediated p53 ubiquitination and degradation. Furthermore, TRIAD1 can inhibit the ubiquitination and proteasomal degradation of growth factor independence 1 (Gfi1), a transcriptional repressor essential for the function and development of many different hematopoietic lineages. TRIAD1 contains an RBR domain that was previously known as RING-BetweenRING-RING domain or TRIAD [two RING fingers and a DRIL (double RING finger linked)] domain. Based on current understanding of the structural biology of RBR ligases, the nomenclature of RBR has been changed to RING1-BRcat (benign-catalytic)-Rcat (required-for-catalysis) recently. The RBR domain uses an auto-inhibitory mechanism to modulate ubiquitination activity, as well as a hybrid mechanism that combines aspects from both RING and HECT E3 ligase functions to facilitate the ubiquitination reaction. This model corresponds to the BRcat domain of TRIAD1 that adopts the same fold as the Rcat domain while lacking the catalytic cysteine residue and ubiquitination activity.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*.
gi 1358101708 309 YCPRPCCQLPVM-QEPGGTMAICSSCNFAFCTLCRLTYHGLSPCKV 353
Cdd:cd20344    11 FCPGPDCPVVIRaLEPKAKRVQCKRCKTSFCFKCGEDYHAPTDCET 56

Ring finger domain;

                          10        20        30
                  ....*....|....*....|....*....|....*
gi 1358101708 221 CSICFCEKLGSDCMYFLECKHVYCKACLKDYFEIQ 255
Cdd:pfam13639   3 CPICLEEFEEGDKVVVLPCGHHFHRECLDKWLRSS 37

Rcat domain found in RING finger protein 19A (RNF19A); RNF19A, also called double ring-finger protein (Dorfin), or p38, is a transmembrane (TM) domain-containing RBR-type E3 ubiquitin-protein ligase that localizes to the ubiquitylated inclusions in Parkinson's disease (PD), dementia with Lewy bodies (LBs), multiple system atrophy, and amyotrophic lateral sclerosis (ALS). It interacts with Psmc3, a protein component of the 19S regulatory cap of the 26S proteasome, and further participates in the ubiquitin-proteasome system in acrosome biogenesis, spermatid head shaping, and development of the head-tail coupling apparatus and tail. It modulates the ubiquitination and degradation of calcium-sensing receptor (CaR), which may contribute to a general mechanism for CaR quality control during biosynthesis. Moreover, RNF19A can also ubiquitylate mutant superoxide dismutase 1 (SOD1), the causative gene of familial ALS. It may associate with endoplasmic reticulum-associated degradation (ERAD) pathway, which is related to the pathogenesis of neurodegenerative disorders, such as PD or Alzheimer's disease. It is also involved in the pathogenic process of PD and LB formation by ubiquitylation of synphilin-1. RNF19A contains an RBR domain followed by three TMs. The RBR domain was previously known as RING-BetweenRING-RING domain or TRIAD [two RING fingers and a DRIL (double RING finger linked)] domain. Based on current understanding of the structural biology of RBR ligases, the nomenclature of RBR has been changed to RING1-BRcat (benign-catalytic)-Rcat (required-for-catalysis) recently. The RBR domain uses an auto-inhibitory mechanism to modulate ubiquitination activity, as well as a hybrid mechanism that combines aspects from both RING and HECT E3 ligase functions to facilitate the ubiquitination reaction. This model corresponds to the Rcat domain of RNF19A that is essential for RBR E3 ligase activity and adopts the same fold as the BRcat domain.

                          10        20        30
                  ....*....|....*....|....*....|....*....
gi 1358101708 403 KSCPCCGTPIQKLD--GCNKMTCTGCMQYFCWICMGSLS 439
Cdd:cd20370    10 KPCPRCAAYIIKMNdgSCNHMTCAVCGCEFCWLCMKEIS 48

BRcat domain found in parkin and similar proteins; Parkin, also called Parkinson juvenile disease protein 2, is an RBR-type E3 ubiquitin-protein ligase that is associated with recessive early onset Parkinson's disease (PD), and exerts a protective effect against dopamine-induced alpha-synuclein-dependent cell toxicity. Mutations in the parkin gene cause autosomal recessive juvenile parkinsonism. Parkin functions within a multiprotein E3 ubiquitin ligase complex, catalyzing the covalent attachment of ubiquitin moieties onto substrate proteins, such as BCL2, SYT11, CCNE1, GPR37, RHOT1/MIRO1, MFN1, MFN2, STUB1, SNCAIP, SEPT5, TOMM20, USP30, ZNF746 and AIMP2. It mediates monoubiquitination as well as Lys6-, Lys11-, Lys48- and Lys63-linked polyubiquitination of substrates depending on the context. Parkin may enhance cell viability and protects dopaminergic neurons from oxidative stress-mediated death by regulating mitochondrial function. It also limits the production of reactive oxygen species (ROS), and regulates cyclin-E during neuronal apoptosis. Moreover, parkin displays a ubiquitin ligase-independent function in transcriptional repression of p53. Parkin contains an N-terminal ubiquitin-like domain and a C-terminal RBR domain that was previously known as RING-BetweenRING-RING domain or TRIAD [two RING fingers and a DRIL (double RING finger linked)] domain. Based on current understanding of the structural biology of RBR ligases, the nomenclature of RBR has been changed to RING1-BRcat (benign-catalytic)-Rcat (required-for-catalysis) recently. The RBR domain uses an auto-inhibitory mechanism to modulate ubiquitination activity, as well as a hybrid mechanism that combines aspects from both RING and HECT E3 ligase functions to facilitate the ubiquitination reaction. This model corresponds to the BRcat domain of parkin that adopts the same fold as the Rcat domain while lacking the catalytic cysteine residue and ubiquitination activity.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|
gi 1358101708 308 VYCPRPCCQLPVMQEPGGTMAIC-SSCNFAFCTLCRLTYH 346
Cdd:cd20340    30 VLCPQPGCGAGLLPEDECNRVTCeLGCGFVFCRECLEAYH 69

RWD, DRWD, and ELF domain family; The family includes the RWD, double-RWD (DRWD), and ELF domains. They belong to the ubiquitin-conjugating (UBC) superfamily that represents a structural domain with an alpha-beta(4)-alpha(3) core fold. The RWD domain (named after three major RWD-containing proteins: RING finger, WD-repeat-containing proteins and DEXD-like helicases) mediates protein-protein interactions in a variety of pathways in eukaryotes. The DRWD domain is responsible for substrate binding. It is involved in interactions with other kinetochore proteins. The ELF (N-terminal E2-like fold) domain is found in all Fanconi anemia group L protein (FANCL) homologs. It is required to promote efficient DNA damage-induced FANCD2 (Fanconi anemia group D2 protein) monoubiquitination in vertebrate cells.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1358101708  15 ALASIYDaDEFrkaesvqggeTRIYLDLPQNFKIFVSGNSNESLqnsgfeyticflPPLVLNFELPPDYPSSSPPSFTLS 94
Cdd:cd11605     1 ALESIYG-DEL----------EVLSDDSPLRFSIRLSPEEEEDD------------PPLELEFTLPPGYPPEEPPLITLR 57

                          90       100       110
                  ....*....|....*....|....*....|....*..
gi 1358101708  95 GKWLSPTQLSALCK-HLDNLWEEHRGRVVLFAWMQFL 130
Cdd:cd11605    58 SPKLSSAERLSLLKlELEEAAEENLGEPMLFDLVEAL 94

Rcat domain found in heme-oxidized IRP2 ubiquitin ligase 1 (HOIL-1) and similar proteins; HOIL-1 is also called RBCK1, HOIL-1L, RanBP-type and C3HC4-type zinc finger-containing protein 1, HBV-associated factor 4, Hepatitis B virus X-associated protein 4, RING finger protein 54 (RNF54), ubiquitin-conjugating enzyme 7-interacting protein 3, or UbcM4-interacting protein 28 (UIP28). Together with the E3 ubiquitin-protein ligase RNF31 (also known as HOIP) and SHANK-associated RH domain interacting protein (SHARPIN), it forms the E3-ligase complex (also known as linear-ubiquitin-chain assembly complex LUBAC) that regulates NF-kappaB activity and apoptosis through conjugation of linear polyubiquitin chains to NF-kappaB essential modulator (also known as NEMO or IKBKG). HOIL-1 plays a crucial role in TNF-alpha-mediated NF-kappaB activation. It also functions as an ubiquitin-protein ligase E3 that interacts with not only PKCbeta but also PKCzeta. It can recognize heme-oxidized IRP2 (iron regulatory protein2) and is thought to affect the turnover of oxidatively damaged proteins. HOIL-1 contains an N-terminal ubiqutin-like (UBL) domain and an Npl4 zinc-finger (NZF) domain, which regulate the interaction with the LUBAC subunit RNF31 and ubiquitin, respectively. The NZF domain belongs to RanBP2-type zinc finger (zf-RanBP2) domain superfamily. In addition, HOIL-1 has an RBR domain that was previously known as RING-BetweenRING-RING domain or TRIAD [two RING fingers and a DRIL (double RING finger linked)] domain. Based on current understanding of the structural biology of RBR ligases, the nomenclature of RBR has been changed to RING1-BRcat (benign-catalytic)-Rcat (required-for-catalysis) recently. The RBR domain uses an auto-inhibitory mechanism to modulate ubiquitination activity, as well as a hybrid mechanism that combines aspects from both RING and HECT E3 ligase functions to facilitate the ubiquitination reaction. This model corresponds to the Rcat domain of HOIL1 that is essential for RBR E3 ligase activity and adopts the same fold as the BRcat domain.

                          10        20        30
                  ....*....|....*....|....*....|..
gi 1358101708 405 CPCCGTPIQKLDGCNKMTCTGCMQYFCWICMG 436
Cdd:cd20358    10 CPQCQVIVQKKDGCDWIRCSMCKTEICWVTKG 41