PHD zinc finger; The plant homeodomain (PHD) finger is a C4HC3 zinc-finger-like motif found in nuclear proteins thought to be involved in epigenetics and chromatin-mediated transcriptional regulation. The PHD finger binds two zinc ions using the so-called 'cross-brace' motif and is thus structurally related to the RING finger and the FYVE finger. It is not yet known if PHD fingers have a common molecular function. Several reports suggest that it can function as a protein-protein interacton domain and it was recently demonstrated that the PHD finger of p300 can cooperate with the adjacent BROMO domain in nucleosome binding in vitro. Other reports suggesting that the PHD finger is a ubiquitin ligase have been refuted as these domains were RING fingers misidentified as PHD fingers.

                           10        20        30        40
                   ....*....|....*....|....*....|....*....|....*
gi 1370472178  212 CYCRKPFAGRPMIECSLCGTWIHLSCAKIKKT--NVPDFFYCQKC 254
Cdd:smart00249   3 SVCGKPDDGGELLQCDGCDRWYHQTCLGPPLLeeEPDGKWYCPKC 47

PHD finger found in PHD finger proteins PHF13 and PHF23; PHF13, also termed survival time-associated PHD finger protein in ovarian cancer 1 (SPOC1), is a novel plant homeodomain (PHD) finger-containing protein that shows strong expression in spermatogonia and ovarian cancer cells, modulates chromatin structure and mitotic chromosome condensation, and is important for proper cell division. It is also required for spermatogonial stem cell differentiation and sustained spermatogenesis. The overexpression of PHF13 associates with unresectable carcinomas and shorter survival in ovarian cancer. PHF23, also termed PHD-containing protein JUNE-1, is a hypothetical protein with a PHD finger. It is encoded by gene PHF23 that acts as a candidate fusion partner for the nucleoporin gene NUP98. The NUP98-PHF23 fusion results from a cryptic translocation t(11;17)(p15;p13) in acute myeloid leukemia (AML).

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                  ....*....|....*....|....*....|....*....|....
gi 1370472178 211 TCYCRKPFAGRPMIECSLCGTWIHLSCAKIKKTNVPDFFYCQKC 254
Cdd:cd15546     1 TCFCGKPFAGRPMIECSECLTWIHLSCAKIRKNNVPEVFICQKC 44

PHD finger found in lysine-specific demethylase 7 (KDM7); KDM7, also termed JmjC domain-containing histone demethylation protein 1D (JHDM1D), or KIAA1718, is a dual histone demethylase that catalyzes demethylation of monomethylated and dimethylated H3K9 (H3K9me2/me1) and H3K27 (H3K27me2/me1), which functions as an eraser of silencing marks on chromatin during brain development. It also plays a tumor-suppressive role by regulating angiogenesis. KDM7 contains a plant homeodomain (PHD) that binds Lys4-trimethylated histone 3 (H3K4me3) and a jumonji domain that demethylates either H3K9me2 or H3K27me2.

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                  ....*....|....*....|....*....|....*....|....*....
gi 1370472178 212 CYCRKPF-AGRPMIECSLCGTWIHLSCAKIKKTNVP--DFFYCQKCKEL 257
Cdd:cd15640     2 CVCRQPYdVNRFMIECDICKDWFHGSCVQVEEHHAAdiDLYHCPNCEVL 50

PHD zinc finger; The plant homeodomain (PHD) finger is a C4HC3 zinc-finger-like motif found in nuclear proteins thought to be involved in epigenetics and chromatin-mediated transcriptional regulation. The PHD finger binds two zinc ions using the so-called 'cross-brace' motif and is thus structurally related to the RING finger and the FYVE finger. It is not yet known if PHD fingers have a common molecular function. Several reports suggest that it can function as a protein-protein interacton domain and it was recently demonstrated that the PHD finger of p300 can cooperate with the adjacent BROMO domain in nucleosome binding in vitro. Other reports suggesting that the PHD finger is a ubiquitin ligase have been refuted as these domains were RING fingers misidentified as PHD fingers.

                           10        20        30        40
                   ....*....|....*....|....*....|....*....|....*
gi 1370472178  212 CYCRKPFAGRPMIECSLCGTWIHLSCAKIKKT--NVPDFFYCQKC 254
Cdd:smart00249   3 SVCGKPDDGGELLQCDGCDRWYHQTCLGPPLLeeEPDGKWYCPKC 47

PHD finger found in PHD finger protein 3 (PHF3), and death-inducer obliterator variants Dido1, Dido2, and Dido3; PHF3 is a human homolog of yeast protein bypass of Ess1 (Bye1), a nuclear protein with a domain resembling the central domain in the transcription elongation factor TFIIS. It is ubiquitously expressed in normal tissues including brain, but its expression is significantly reduced or lost in glioblastomas. PHF3 contains an N-terminal plant homeodomain (PHD) finger, a central RNA polymerase II (Pol II)-binding TFIIS-like domain (TLD) domain, and a C-terminal Spen paralogue and orthologue C-terminal (SPOC) domain. This family also includes Dido gene encoding three alternative splicing variants (Dido1, 2, and 3), which have been implicated in a number of cellular processes such as apoptosis and chromosomal segregation, particularly in the hematopoietic system. Dido1 is important for maintaining embryonic stem (ES) cells and directly regulates the expression of pluripotency factors. It is the shortest isoform that contains only a highly conserved PHD finger responsible for the binding of histone H3 with a higher affinity for trimethylated lysine4 (H3K4me3). Gene Dido1 is a Bone morphogenetic protein (BMP) target gene and promotes BMP-induced melanoma progression. It also triggers apoptosis after nuclear translocation and caspase upregulation. Dido3 is the largest isoform and is ubiquitously expressed in all human tissues. It is dispensable for ES cell self-renewal and pluripotency, but is involved in the maintenance of stem cell genomic stability and tumorigenesis. Dido3 contains a PHD finger, a transcription elongation factor S-II subunit M (TFSIIM) domain, a SPOC module, and a long C-terminal region (CT) of unknown homology.

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                  ....*....|....*....|....*....|....*....|....*....
gi 1370472178 212 CYCRKPFAGRPMIECSLCGTWIHLSCAKIKKTNVPDF------FYCQKC 254
Cdd:cd15552     2 CICRKPHNNRFMICCDRCEEWFHGDCVGITEAQGKEMeenieeYVCPKC 50

PHD finger superfamily; The PHD finger superfamily includes a canonical plant homeodomain (PHD) finger typically characterized as Cys4HisCys3, and a non-canonical extended PHD finger, characterized as Cys2HisCys5HisCys2His. Variations include the RAG2 PHD finger characterized by Cys3His2Cys2His and the PHD finger 5 found in nuclear receptor-binding SET domain-containing proteins characterized by Cys4HisCys2His. The PHD finger is also termed LAP (leukemia-associated protein) motif or TTC (trithorax consensus) domain. Single or multiple copies of PHD fingers have been found in a variety of eukaryotic proteins involved in the control of gene transcription and chromatin dynamics. PHD fingers can recognize the unmodified and modified histone H3 tail, and some have been found to interact with non-histone proteins. They also function as epigenome readers controlling gene expression through molecular recruitment of multi-protein complexes of chromatin regulators and transcription factors. The PHD finger domain SF is structurally similar to the RING and FYVE_like superfamilies.

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                  ....*....|....*....|....*....|....*....|....*.
gi 1370472178 212 CYCRKPF-AGRPMIECSLCGTWIHLSCAKIKKTNVPDF--FYCQKC 254
Cdd:cd15489     3 IVCGKGGdLGGELLQCDGCGKWFHADCLGPPLSSFVPNgkWICPVC 48

PHD finger found in mixed lineage leukemia 5 (MLL5); MLL5 is a histone methyltransferase that plays a key role in hematopoiesis, spermatogenesis and cell cycle progression. It contains a single plant homeodomain (PHD) finger followed by a catalytic SET domain. MLL5 can be recruited to E2F1-responsive promoters to stimulate H3K4 trimethylation and transcriptional activation by binding to the cell cycle regulator host cell factor (HCF-1), thereby facilitating the cell cycle G1 to S phase transition. It is also involved in mitotic fidelity and genomic integrity by modulating the stability of the chromosomal passenger complex (CPC) via the interaction with Borealin. Moreover, MLL5 is a component of a complex associated with retinoic acid receptor that requires GlcN Acylation of its SET domain in order to activate its histone lysine methyltransferase activity. It also participates in the camptothecin (CPT)-induced p53 activation. Furthermore, MLL5 indirectly regulates H3K4 methylation, represses cyclin A2 (CycA) expression, and promotes myogenic differentiation.

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                  ....*....|....*....|....*....|....*....|....
gi 1370472178 211 TCYCRKPFAGRPMIECSLCGTWIHLSCAKIKKTNVPDFFYCQKC 254
Cdd:cd15550     1 RCICGFEHDDGFMICCDKCSVWQHGDCMGIDRENIPDSYLCEQC 44

PHD finger found in Set1 complex component SPP1; Set1C component SPP1, also called COMPASS component Spp1, or Complex proteins associated with set1 protein Spp1, or Suppressor of PRP protein 1, is a component of the COMPASS complex that links histone methylation to initiation of meiotic recombination. It induces double-strand break (DSB) formation by tethering to recombinationally cold regions. SPP1 interacts with H3K4me3 and Mer2, a protein required for DSB formation, to promote recruitment of potential meiotic DSB sites to the chromosomal axis. SPP1 contains a PHD finger, a zinc binding motif.

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                  ....*....|....*....|....*....|....*....|....*
gi 1370472178 212 CYCRKPFAGRPMIECSLCGTWIHLSCAKIKKTNVP--DFFYCQKC 254
Cdd:cd16039     2 CICQKPDDGRWMIACDGCDEWYHFTCVNIPEADVElvDSFFCPPC 46

PHD finger found in Transcription factor 19 (TCF-19), Lysine-specific demethylase KDM5A and KDM5B, and other similar proteins; TCF-19 was identified as a putative trans-activating factor with expression beginning at the late G1-S boundary in dividing cells. It functions as a novel islet factor necessary for proliferation and survival in the INS-1 beta cell line. It plays an important role in susceptibility to both Type 1 Diabetes Mellitus (T1DM) and Type 2 Diabetes Mellitus (T2DM); it has been suggested that it may positively impact beta cell mass under conditions of beta cell stress and increased insulin demand. KDM5A was originally identified as a retinoblastoma protein (Rb)-binding partner and its inactivation may be important for Rb to promote differentiation. It is involved in transcription through interaction with TBP, p107, nuclear receptors, Myc, Sin3/HDAC, Mad1, RBP-J, CLOCK, and BMAL1. KDM5B has a restricted expression pattern in the testis, ovary, and transiently in the mammary gland of the pregnant female and has been shown to be upregulated in breast cancer, prostate cancer, and lung cancer, suggesting a potential role in tumorigenesis. Both KDM5A and KDM5B function as trimethylated histone H3 lysine 4 (H3K4me3) demethylases. This family also includes Caenorhabditis elegans Lysine-specific demethylase 7 homolog (ceKDM7A). ceKDM7A (also termed JmjC domain-containing protein 1.2, PHD finger protein 8 homolog, or PHF8 homolog) is a plant homeodomain (PHD)- and JmjC domain-containing protein that functions as a histone demethylase specific for H3K9me2 and H3K27me2. The binding of the PHD finger to H3K4me3 guides H3K9me2- and H3K27me2-specific demethylation by its catalytic JmjC domain in a trans-histone regulation mechanism. In addition, this family includes plant protein OBERON 1 and OBERON 2, Alfin1-like (AL) proteins, histone acetyltransferases (HATs) HAC, and AT-rich interactive domain-containing protein 4 (ARID4).

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                  ....*....|....*....|....*....|...
gi 1370472178 224 IECSLCGTWIHLSCAKIK--KTNVPDFFYCQKC 254
Cdd:cd15517    17 VQCDGCDKWFHQFCLGLSneRYADEDKFKCPNC 49

PHD domain found in Saccharomyces cerevisiae bypass of ESS1 protein 1 (Bye1p), the E3 Sumo Ligase SIZ1, and similar proteins; Yeast Bye1p is a nuclear transcription factor with a domain resembling the central domain in the transcription elongation factor TFIIS and plays an inhibitory role during transcription elongation. It functions as a multicopy suppressor of Ess1, a peptidyl-prolyl cis-trans isomerase involved in proline isomerization of the C-terminal domain (CTD) of RNA polymerase II (Pol II). Bye1p contains an N-terminal plant homeodomain (PHD) finger, a central Pol II-binding TFIIS-like domain (TLD) domain, and a C-terminal Spen paralogue and orthologue C-terminal (SPOC) domain. The PHD domain binds to a histone H3 tail peptide containing trimethylated lysine 4 (H3K4me3). The TLD domain is responsible for the association with chromatin. Plant SIZ1 protein is a SUMO (small ubiquitin-related modifier) E3 ligase that facilitates conjugation of SUMO to substrate target proteins (sumoylation) and belongs to the protein inhibitor of activated STAT (PIAS) protein family. It negatively regulates abscisic acid (ABA) signaling, which is dependent on the bZIP transcripton factor ABI5. It also modulates plant growth and plays a role in drought stress response likely through the regulation of gene expression. SIZ1 functions as a floral repressor that not only represses the salicylic acid (SA)-dependent pathway, but also promotes FLOWERING LOCUS C (FLC) expression by repressing FLOWERING LOCUS D (FLD) activity through sumoylation. SIZ1 contains a PHD finger, which specifically binds methylated histone H3 at lysine 4 and arginine 2.

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                  ....*....|....*....|....*....|....*....|....*....
gi 1370472178 212 CYCRKPFAGRPMIECSLCGTWIHLSCAKIKKT------NVPDFFYCQKC 254
Cdd:cd15570     2 CPCGSSMEDGSMIQCEGCKTWQHMDCVLIPDKpadglpELPSKFYCELC 50

PHD finger found in histone lysine demethylase PHF8; PHF8, also termed PHD finger protein 8, or KDM7B, is a monomethylated histone H4 lysine 20 (H4K20me1) demethylase that transcriptionally regulates many cell cycle genes. It also preferentially acts on H3K9me2 and H3K9me1. PHF8 is modulated by CDC20-containing anaphase-promoting complex (APC (cdc20)) and plays an important role in the G2/M transition. It acts as a critical molecular sensor for mediating retinoic acid (RA) treatment response in RAR alpha-fusion-induced leukemia. Moreover, PHF8 is essential for cytoskeleton dynamics and is associated with X-linked mental retardation. PHF8 contains an N-terminal plant homeodomain (PHD) finger followed by a JmjC domain. The PHD finger mediates binding to nucleosomes at active gene promoters and the JmjC domain catalyzes the demethylation of mono- or dimethyl-lysines.

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                  ....*....|....*....|....*....|....*....|....*....
gi 1370472178 210 ITCYCRKPF-AGRPMIECSLCGTWIHLSCAKIKKTNVP--DFFYCQKCK 255
Cdd:cd15642     1 VYCLCRLPYdVTRFMIECDVCQDWFHGSCVGVEEEKAAeiDLYHCPNCQ 49

PHD-like zinc-binding domain; The members of this family are annotated as containing PHD domain, but the zinc-binding region here is not typical of PHD domains. The conformation here is a well-conserved cysteine-histidine rich region spanning 90 residues, where the Cys and His are arranged as HxxC(31)CxxC(6)CxxCxxxxCxxxxHxxC (21)CxxH.

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                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1370472178 175 STETSQDGDASSSEGEMRVMDEDImvesgdDSWDLITCYCRKPFaGrPMIECSL--CGTWIHLSCAK-------IKKTNV 245
Cdd:pfam13771   8 SPELVQRGNDSMGFPIEDIEKIPK------RRWKLKCYLCKKKG-G-ACIQCSKknCRRAFHVTCALeagllmqFDEDNG 79

                  ....*....
gi 1370472178 246 PDFFYCQKC 254
Cdd:pfam13771  80 TFKSYCKKH 88

PHD finger found in Arabidopsis thaliana AT-rich interactive domain-containing protein 4 (ARID4) and similar proteins; This family includes A. thaliana ARID4 (ARID domain-containing protein 4) and similar proteins. Their biological roles remain unclear, but they all contain an AT-rich interactive domain (ARID) and a plant homeodomain (PHD) finger at the C-terminus. ARID is a helix-turn-helix motif-based DNA-binding domain conserved in all eukaryotes. PHD fingers can recognize the unmodified and modified histone H3 tail, and some have been found to interact with non-histone proteins.

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                  ....*....|....*....|....*....|....*....|....*....
gi 1370472178 213 YCRKPFAGRPMIECSLCGTWIHLSCAKIK-----KTNVPD--FFYCQKC 254
Cdd:cd15615     9 YEENEGDEKEWVQCDSCSEWVHFECDGRTglgafKYAKSDglQYVCPRC 57

PHD finger 2 found in Lysine-specific demethylase KDM5A, KDM5B, KDM5C, KDM5D, and similar proteins; The JARID subfamily within the JmjC proteins includes Lysine-specific demethylase KDM5A, KDM5B, KDM5C, KDM5D and a Drosophila homolog protein, little imaginal discs (Lid). KDM5A was originally identified as a retinoblastoma protein (Rb)-binding partner and its inactivation may be important for Rb to promote differentiation. It is involved in transcription through interacting with TBP, p107, nuclear receptors, Myc, Sin3/HDAC, Mad1, RBP-J, CLOCK, and BMAL1. KDM5B has a restricted expression pattern in the testis, ovary, and transiently in the mammary gland of the pregnant female and has been shown to be upregulated in breast cancer, prostate cancer, and lung cancer, suggesting a potential role in tumorigenesis. Both KDM5A and KDM5B function as trimethylated histone H3 lysine 4 (H3K4me3) demethylases. KDM5C is a H3K4 trimethyl-histone demethylase that catalyzes demethylation of H3K4me3 and H3K4me2 to H3K4me1. It plays a role in neuronal survival and dendrite development. KDM5C defects are associated with X-linked mental retardation (XLMR). KDM5D is a male-specific antigen that shows a demethylase activity specific for di- and tri-methylated histone H3K4 (H3K4me3 and H3K4me2), and has a male-specific function as a histone H3K4 demethylase by recruiting a meiosis-regulatory protein, MSH5, to condensed DNA. KDM5D directly interacts with a polycomb-like protein Ring6a/MBLR, and plays a role in regulation of transcriptional initiation through H3K4 demethylation. The family also includes Drosophila melanogaster protein little imaginal discs (Lid) that functions as a JmjC-dependent trimethyl histone H3K4 (H3K4me3) demethylase, which is required for dMyc-induced cell growth. It positively regulates Hox gene expression in S2 cells. Members in this family contain the catalytic JmjC domain, JmjN, the BRIGHT domain, which is an AT-rich interacting domain (ARID), and a Cys5HisCys2 zinc finger, as well as two or three plant homeodomain (PHD) fingers. This model corresponds to the second PHD finger.

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                  ....*....|....*....|....*....|.
gi 1370472178 212 CYCRKPFAGrPMIECSLCGTWIHLSCAKIKK 242
Cdd:cd15516     2 CLCGKALAA-GMLQCELCQDWFHGSCVAVPR 31

PHD finger found in PHD finger protein 20 (PHF20) and PHD finger protein 20-like protein 1 (P20L1); PHF20, also termed Glioma-expressed antigen 2, or hepatocellular carcinoma-associated antigen 58, or novel zinc finger protein, or transcription factor TZP (referring to Tudor and zinc finger domain containing protein), is a regulator of NF-kappaB activation by disrupting recruitment of PP2A to p65. It also functions as a transcription factor that binds Akt and plays a role in Akt cell survival/growth signaling. Moreover, it transcriptionally regulates p53. The phosphorylation of PHF20 on Ser291 mediated by protein kinase B (PKB) is essential in tumorigenesis via the regulation of p53 mediated signaling. P20L1 is an active malignant brain tumor (MBT) domain-containing protein that binds to monomethylated lysine 142 on DNA (Cytosine-5) Methyltransferase 1 (DNMT1) (DNMT1K142me1) and colocalizes at the perinucleolar space in a SET7-dependent manner. Its MBT domain reads and controls enzyme levels of methylated DNMT1 in cells, thus representing a novel antagonist of DNMT1 proteasomal degradation. Both PHF20 and PHF20L1 contain an N-terminal MBT domain, two Tudor domains, a plant homeodomain (PHD) finger and the putative DNA-binding domains, AT hook and Cys2His2-type zinc finger.

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                  ....*....|....*....|....*....|....*....|....
gi 1370472178 212 CYCRKPFAGRPMIECSLCGTWIHLSCAKI-KKTNVPDFFYCQKC 254
Cdd:cd15549     2 CICGVNEENGLMIQCELCLCWQHGVCMGIeEEESVPERYVCYVC 45