BRcat domain found in F-box only protein 43 (FBXO43); FBXO43, also called FBX43 or endogenous meiotic inhibitor 2 (EMI2), plays a key role during the meiotic cell cycle. It is required to establish and maintain the arrest of oocytes at the second meiotic metaphase until fertilization. It probably acts by inhibiting the anaphase-promoting complex/cyclosome (APC/C) ubiquitin ligase. It may recognize and bind to some phosphorylated proteins and promotes their ubiquitination and degradation. FBXO43 contains an F-box domain, and the first half of the 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 (benign-catalytic) domain that adopts the same fold as the Rcat domain while lacking the catalytic cysteine residue and ubiquitination activity.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 2251171359 600 DEALKPCPRCQSPAKYQPYKKRGLCSRTACGFDFCVLCLCAYHGSEECSRG 650
Cdd:cd20365     1 DEALKPCPRCQSPAKYQPVKKRGLCSREACGFDFCVLCLCAFHGSKECTSG 51

BRcat domain found in F-box only protein 43 (FBXO43); FBXO43, also called FBX43 or endogenous meiotic inhibitor 2 (EMI2), plays a key role during the meiotic cell cycle. It is required to establish and maintain the arrest of oocytes at the second meiotic metaphase until fertilization. It probably acts by inhibiting the anaphase-promoting complex/cyclosome (APC/C) ubiquitin ligase. It may recognize and bind to some phosphorylated proteins and promotes their ubiquitination and degradation. FBXO43 contains an F-box domain, and the first half of the 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 (benign-catalytic) domain that adopts the same fold as the Rcat domain while lacking the catalytic cysteine residue and ubiquitination activity.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 2251171359 600 DEALKPCPRCQSPAKYQPYKKRGLCSRTACGFDFCVLCLCAYHGSEECSRG 650
Cdd:cd20365     1 DEALKPCPRCQSPAKYQPVKKRGLCSREACGFDFCVLCLCAFHGSKECTSG 51

IBR domain, a half RING-finger domain; The IBR (In Between Ring fingers) domain is often found to occur between pairs of ring fingers (pfam00097). This domain has also been called the C6HC domain and DRIL (for double RING finger linked) domain. Proteins that contain two Ring fingers and an IBR domain (these proteins are also termed RBR family proteins) are thought to exist in all eukaryotic organizms. 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 ubiquitin ligase Parkin is an RBR family protein whose mutations are involved in forms of familial Parkinson's disease.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 2251171359 588 EEYVKVAKTLFIDEA--LKPCPR--CQSPAKYQPYKKRGL---CSRtaCGFDFCVLCLCAYHGSEEC 647
Cdd:pfam01485   1 EKYEKLLLKSYVESDpnLKWCPTpdCGYIIELTDGCSNTShvtCSK--CGHEFCFNCKEEWHEGLTC 65

A Receptor for Ubiquitination Targets;

                           10        20
                   ....*....|....*....|....*....
gi 2251171359  473 HVLAMVLDSLTAESLCSVWKVSRNWREII 501
Cdd:smart00256   4 EILEEILSKLDPKDLLRLRKVSRKWRSLI 32

BRcat domain found in F-box only protein 43 (FBXO43); FBXO43, also called FBX43 or endogenous meiotic inhibitor 2 (EMI2), plays a key role during the meiotic cell cycle. It is required to establish and maintain the arrest of oocytes at the second meiotic metaphase until fertilization. It probably acts by inhibiting the anaphase-promoting complex/cyclosome (APC/C) ubiquitin ligase. It may recognize and bind to some phosphorylated proteins and promotes their ubiquitination and degradation. FBXO43 contains an F-box domain, and the first half of the 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 (benign-catalytic) domain that adopts the same fold as the Rcat domain while lacking the catalytic cysteine residue and ubiquitination activity.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 2251171359 600 DEALKPCPRCQSPAKYQPYKKRGLCSRTACGFDFCVLCLCAYHGSEECSRG 650
Cdd:cd20365     1 DEALKPCPRCQSPAKYQPVKKRGLCSREACGFDFCVLCLCAFHGSKECTSG 51

BRcat domain found in early mitotic inhibitor (EMI) subfamily of F-box proteins; The EMI subfamily includes FBXO5 (EMI1) and FBXO43 (EMI2), which are anaphase-promoting-complex/cyclosome (APC/C) inhibitors that bind APC/C-CCD20 (Cell division cycle protein 20) and/or APC/C-CDH1 (CDC20 homolog 1) complexes. FBXO5, also called FBX5, or early mitotic inhibitor 1 (EMI1), acts as a regulator that inhibits the anaphase-promoting complex/cyclosome (APC/C), which controls cell cycle progression through the sequential degradation of various substrates from S phase to early mitosis. During the mitotic cell cycle, it plays a role as both substrate and inhibitor of the APC-FZR1 complex. During G1 phase, it plays a role as substrate of the APC-FZR1 complex E3 ligase. FBXO43, also called FBX43, or endogenous meiotic inhibitor 2 (EMI2), plays a key role during the meiotic cell cycle. It is required to establish and maintain the arrest of oocytes at the second meiotic metaphase until fertilization. It probably acts by inhibiting the APC/C ubiquitin ligase. It may recognize and bind to some phosphorylated proteins and promote their ubiquitination and degradation. Both FBXO5 and FBXO43 contain an F-box domain, and the first half of the 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 the EMI subfamily that adopts the same fold as the Rcat domain while lacking the catalytic cysteine residue and ubiquitination activity.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*....
gi 2251171359 600 DEALKPCPRCQSPAKYQPYKKRGLCSRTACGFDFCVLCLCAYHGSEECS 648
Cdd:cd20348     1 GESLRPCPRCSSPAKVDPVEQRATCTRETCGFDFCTKCLCEFHGSKPCP 49

F-box domain found in the early mitotic inhibitor (EMI) family of F-box proteins; The EMI family includes FBX5 (EMI1) and FBX43 (EMI2), which are anaphase-promoting complex/cyclosome (APC/C) inhibitors that bind APC/C-CCD20 (Cell division cycle protein 20) and/or APC/C-CDH1 (CDC20 homologue 1) complexes. The F-box domain has a role in mediating protein-protein interactions in a variety of contexts, such as polyubiquitination, transcription elongation, centromere binding and translational repression.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*...
gi 2251171359 464 TELKYRNLKHVLAMVLDSLTAESLCSVWKVSRNWREIIVQDKKANRRR 511
Cdd:cd22086     1 SELHKRNCPHILSKILSYLSPEDLCRVSCVSKTWRQICLSDPKANRRR 48

BRcat 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 may also 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 function to facilitate the ubiquitination reaction. This model corresponds to the BRcat domain of RNF14 that adopts the same fold as the Rcat domain while lacking the catalytic cysteine residue and ubiquitination activity.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....
gi 2251171359 606 CPR--CQSPAKYQPYKKRGLCSrtACGFDFCVLCLCAYHGSEEC 647
Cdd:cd20341    10 CPRpsCQTPVILEPDENLGICP--SCNYAFCTLCRETYHGVSPC 51

IBR domain, a half RING-finger domain; The IBR (In Between Ring fingers) domain is often found to occur between pairs of ring fingers (pfam00097). This domain has also been called the C6HC domain and DRIL (for double RING finger linked) domain. Proteins that contain two Ring fingers and an IBR domain (these proteins are also termed RBR family proteins) are thought to exist in all eukaryotic organizms. 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 ubiquitin ligase Parkin is an RBR family protein whose mutations are involved in forms of familial Parkinson's disease.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 2251171359 588 EEYVKVAKTLFIDEA--LKPCPR--CQSPAKYQPYKKRGL---CSRtaCGFDFCVLCLCAYHGSEEC 647
Cdd:pfam01485   1 EKYEKLLLKSYVESDpnLKWCPTpdCGYIIELTDGCSNTShvtCSK--CGHEFCFNCKEEWHEGLTC 65

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        40
                  ....*....|....*....|....*....|....*....|....*.
gi 2251171359 604 KPCPRCQSPAKyqpyKKRG---LCSRTACGFDFCVLCLCAY--HGS 644
Cdd:cd22583     3 KPCPKCKRPIE----KNQGcmhMTCSPPCKHEFCWLCLGPWseHGE 44

F-box domain found in F-box/WD repeat-containing protein 1B (FBXW1B) and similar proteins; FBXW1B, also called F-box/WD repeat-containing protein 11 (FBXW11), F-box and WD repeats protein beta-TrCP2, or homologous to Slimb protein (HOS), is the substrate-recognition component of an SCF (SKP1-CUL1-F-box protein) E3 ubiquitin-protein ligase complex which mediates the ubiquitination and subsequent proteasomal degradation of target proteins, such as IFNAR1, CEP68 and CDC25A, as well as phosphorylated CTNNB1, NFKBIA, PER1 and PER2. The F-box domain has a role in mediating protein-protein interactions in a variety of contexts, such as polyubiquitination, transcription elongation, centromere binding and translational repression.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|.
gi 2251171359 461 DILTELKYRNLKHVLAMVLDSLTAESLCSVWKVSRNWREII 501
Cdd:cd22183     3 DFITALPAKGLDHIAENILSYLDAESLCAAELVCKEWQRVI 43

A Receptor for Ubiquitination Targets;

                           10        20
                   ....*....|....*....|....*....
gi 2251171359  473 HVLAMVLDSLTAESLCSVWKVSRNWREII 501
Cdd:smart00256   4 EILEEILSKLDPKDLLRLRKVSRKWRSLI 32