RING finger, HC subclass, found in apoptosis protein c-IAP1, c-IAP2, livin, and similar proteins; The cellular inhibitor of apoptosis protein c-IAPs function as ubiquitin E3 ligases that mediate the ubiquitination of substrates involved in apoptosis, nuclear factor-kappaB (NF-kappaB) signaling, and oncogenesis. Unlike other IAPs, such as XIAP, c-IAPs exhibit minimal binding to caspases and may not play an important role in the inhibition of these proteases. c-IAP1, also known as baculoviral IAP repeat-containing protein BIRC2, IAP-2, RING finger protein 48, or TNFR2-TRAF-signaling complex protein 2, is a potent regulator of the tumor necrosis factor (TNF) receptor family and NF-kappaB signaling pathways in the cytoplasm. It can also regulate E2F1 transcription factor-mediated control of cyclin transcription in the nucleus. c-IAP2, also known as BIRC3, IAP-1, apoptosis inhibitor 2 (API2), or IAP homolog C, also influences ubiquitin-dependent pathways that modulate innate immune signalling by activation of NF-kappaB. c-IAPs contain three N-terminal baculoviral IAP repeat (BIR) domains that enable interactions with proteins, a ubiquitin-association (UBA) domain that is responsible for the binding of polyubiquitin (polyUb), a caspase activation and recruitment domain (CARD) that serves as a protein interaction surface, and a C3HC4-type RING-HC finger at the carboxyl terminus that is required for ubiquitin ligase activity. Livin, also known as baculoviral IAP repeat-containing protein 7 (BIRC7), kidney inhibitor of apoptosis protein (KIAP), melanoma inhibitor of apoptosis protein (ML-IAP), or RING finger protein 50, was identified as the melanoma IAP. It plays crucial roles in apoptosis, cell proliferation, and cell cycle control. Its anti-apoptotic activity is regulated by the inhibition of caspase-3, -7, and -9. Its E3 ubiquitin-ligase-like activity promotes degradation of Smac/DIABLO, a critical endogenous regulator of all IAPs. Unlike other family members, mammalian livin contains a single BIR domain and a C3HC4-type RING-HC finger. The UBA domain can be detected in non-mammalian homologs of livin.

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                ....*....|....*....|....*....|....*....|....*.
gi 42571929 293 CKLCNVKNVSVLLVPCRHLSLCKDCDVFTGVCPVCQSLKTSSVQVF 338
Cdd:cd16713  10 CKVCMDKEVSIVFIPCGHLVVCTECAPSLRKCPICRATIKGTVRTF 55

RING finger, HC subclass, found in apoptosis protein c-IAP1, c-IAP2, livin, and similar proteins; The cellular inhibitor of apoptosis protein c-IAPs function as ubiquitin E3 ligases that mediate the ubiquitination of substrates involved in apoptosis, nuclear factor-kappaB (NF-kappaB) signaling, and oncogenesis. Unlike other IAPs, such as XIAP, c-IAPs exhibit minimal binding to caspases and may not play an important role in the inhibition of these proteases. c-IAP1, also known as baculoviral IAP repeat-containing protein BIRC2, IAP-2, RING finger protein 48, or TNFR2-TRAF-signaling complex protein 2, is a potent regulator of the tumor necrosis factor (TNF) receptor family and NF-kappaB signaling pathways in the cytoplasm. It can also regulate E2F1 transcription factor-mediated control of cyclin transcription in the nucleus. c-IAP2, also known as BIRC3, IAP-1, apoptosis inhibitor 2 (API2), or IAP homolog C, also influences ubiquitin-dependent pathways that modulate innate immune signalling by activation of NF-kappaB. c-IAPs contain three N-terminal baculoviral IAP repeat (BIR) domains that enable interactions with proteins, a ubiquitin-association (UBA) domain that is responsible for the binding of polyubiquitin (polyUb), a caspase activation and recruitment domain (CARD) that serves as a protein interaction surface, and a C3HC4-type RING-HC finger at the carboxyl terminus that is required for ubiquitin ligase activity. Livin, also known as baculoviral IAP repeat-containing protein 7 (BIRC7), kidney inhibitor of apoptosis protein (KIAP), melanoma inhibitor of apoptosis protein (ML-IAP), or RING finger protein 50, was identified as the melanoma IAP. It plays crucial roles in apoptosis, cell proliferation, and cell cycle control. Its anti-apoptotic activity is regulated by the inhibition of caspase-3, -7, and -9. Its E3 ubiquitin-ligase-like activity promotes degradation of Smac/DIABLO, a critical endogenous regulator of all IAPs. Unlike other family members, mammalian livin contains a single BIR domain and a C3HC4-type RING-HC finger. The UBA domain can be detected in non-mammalian homologs of livin.

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                ....*....|....*....|....*....|....*....|....*.
gi 42571929 293 CKLCNVKNVSVLLVPCRHLSLCKDCDVFTGVCPVCQSLKTSSVQVF 338
Cdd:cd16713  10 CKVCMDKEVSIVFIPCGHLVVCTECAPSLRKCPICRATIKGTVRTF 55

RING finger, HC subclass, found in E3 ubiquitin-protein ligase XIAP, baculoviral IAP repeat-containing protein 8 (BIRC8) and similar proteins; XIAP, also known as baculoviral IAP repeat-containing protein 4 (BIRC4), IAP-like protein (ILP), inhibitor of apoptosis protein 3 (IAP-3), or X-linked inhibitor of apoptosis protein (X-linked IAP), is a potent suppressor of apoptosis that directly inhibits specific members of the caspase family of cysteine proteases, including caspase-3, -7, and -9. It promotes proteasomal degradation of caspase-3 and enhances its anti-apoptotic effect in Fas-induced cell death. The ubiquitin-protein ligase (E3) activity of XIAP also exhibits in the ubiquitination of second mitochondria-derived activator of caspases (Smac). The mitochondrial proteins, Smac/DIABLO and Omi/HtrA2, can inhibit the antiapoptotic activity of XIAP. XIAP has also been implicated in several intracellular signaling cascades involved in the cellular response to stress, such as the c-Jun N-terminal kinase (JNK), the nuclear factor-kappaB (NF-kappaB), and the transforming growth factor-beta (TGF-beta) pathways. Moreover, XIAP can regulate copper homeostasis by interacting with MURR1. BIRC8, also known as inhibitor of apoptosis-like protein 2, IAP-like protein 2, ILP-2, or testis-specific inhibitor of apoptosis, is a tissue-specific homolog of E3 ubiquitin-protein ligase XIAP. It has been implicated in the control of apoptosis in the testis by direct inhibition of caspase 9. Both XIAP and BIRC8 contain three N-terminal baculoviral IAP repeat (BIR) domains, a ubiquitin-association (UBA) domain and a C3HC4-type RING-HC finger at the carboxyl terminus.

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                ....*....|....*....|....*....|....*....|....*.
gi 42571929 293 CKLCNVKNVSVLLVPCRHLSLCKDCDVFTGVCPVCQSLKTSSVQVF 338
Cdd:cd16714  17 CKICMDRNISIVFIPCGHLVTCKQCAEALDKCPICCTVITFKQKIF 62

RING finger, HC subclass, found in RING finger protein unkempt (UNK), unkempt-like (UNKL), and similar proteins; UNK, also known as zinc finger CCCH domain-containing protein 5, is a metazoan-specific zinc finger protein enriched in embryonic brains. It may play a broad regulatory role during the formation of the central nervous system (CNS). It is a sequence-specific RNA-binding protein required for early neuronal morphology. UNK is a neurogenic component of the mTOR pathway, and functions as a negative regulator of the timing of photoreceptor differentiation. It also specifically binds to Brg/Brm-associated factor BAF60b and promotes its ubiquitination in a Rac1-dependent manner. UNKL, also known as zinc finger CCCH domain-containing protein 5-like, is a putative E3 ubiquitin-protein ligase that may participate in a protein complex showing an E3 ligase activity regulated by RAC1. Both UNK and UNKL contain several tandem CCCH-type zinc fingers at the N-terminus, and a C3HC4-type RING-HC finger at its C-terminus.

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gi 42571929 291 MRCKLCNVKNVSVLLVPCRHLSLCKDCDVFTGVCPVCQ 328
Cdd:cd16614   1 KKCMKCEERNRSVAVLPCQHYVLCEQCAETATECPYCH 38

Modified RING finger, HC subclass (C3HC5-type), found in cell growth regulator with RING finger domain protein 1 (CGRRF1) and similar proteins; CGRRF1, also known as cell growth regulatory gene 19 protein (CGR19) or RING finger protein 197 (RNF197), functions as a novel biomarker to monitor endometrial sensitivity and response to insulin-sensitizing drugs, such as metformin, in the context of obesity. CGRRF1 contains a C-terminal modified C3HC5-type RING-HC finger, which is distinguished from typical C3HC4 RING-HC finger due to the existence of the additional cysteine residue in the middle portion of the RING finger domain.

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                ....*....|....*....|....*....|....*.
gi 42571929 293 CKLCNVKNVSVLLVPCRHLSLCKDCDVFTGVCPVCQ 328
Cdd:cd16787   3 CVVCQNAPVNRVLLPCRHACVCDECFKRLQRCPMCR 38

RING finger, HC subclass, found in RNA-binding proteins of the evolutionarily-conserved MEX-3 family; MEX-3 phosphoproteins are found in vertebrates. They are mediators of post-transcriptional regulation in different organisms, and have been implicated in many core biological processes, including embryonic development, epithelial homeostasis, immune responses, metabolism, and cancer. They contain two K homology (KH) domains that provide RNA-binding capacity, and a C-terminal C3HC4-type RING-HC finger. They shuttle between the nucleus and the cytoplasm via the CRM1-dependent export pathway. The RNA-binding protein MEX-3 from nematode Caenorhabditis elegans is the founding member of the MEX-3 family. Due to the lack of a RING-HC finger, it is not included here.

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                ....*....|....*....|....*....|....*....|....*....|.
gi 42571929 293 CKLCNVKNVSVLLVPCRHLSLCKDC-----DVFTGVCPVCQSLKTSSVQVF 338
Cdd:cd16518   3 CVVCFESEVVAALVPCGHNLFCMECanricEKSDPECPVCHTPVTQAIRIF 53

RING finger, HC subclass, found in RING finger and SPRY domain-containing protein 1 (RSPRY1) and similar proteins; RSPRY1 is a hypothetical RING and SPRY domain-containing protein of unknown physiological function. Mutations in its corresponding gene RSPRY1 may associate with a distinct skeletal dysplasia syndrome. RSPRY1 contains a B30.2/SPRY domain and a C3HC4-type RING-HC finger.

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                ....*....|....*....|....*....|....*..
gi 42571929 293 CKLCNVKNVSVLLVPCRHLSLCKDCDVFTGVCPVCQS 329
Cdd:cd16566   5 CTLCFDKVADTELRPCGHSGFCMECALQLETCPLCRQ 41

RING finger, HC subclass, found in RNA-binding protein MEX3C; MEX3C, also known as RING finger and KH domain-containing protein 2 (RKHD2), or RING finger protein 194 (RNF194), is an RNA-binding phosphoprotein that acts as a suppressor of chromosomal instability. It functions as an ubiquitin E3 ligase responsible for the post-transcriptional, HLA-A allotype-specific regulation of MHC class I molecules (MHC-I). It also modifies retinoic acid inducible gene-1 (RIG-I) in stress granules and plays a critical role in eliciting antiviral immune responses. Moreover, MEX3C plays an essential role in normal postnatal growth via enhancing the local expression of insulin-like growth factor 1 (IGF1) in bone. It may also be involved in metabolic regulation of energy balance. MEX3C contains two K homology (KH) domains that provide RNA-binding capacity, and a C-terminal C3HC4-type RING-HC finger. Like other MEX-3 family proteins, MEX3C shuttles between the nucleus and the cytoplasm via the CRM1-dependent export pathway.

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                ....*....|....*....|....*....|....*....|....*....|.
gi 42571929 293 CKLCNVKNVSVLLVPCRHLSLCKD-----CDVFTGVCPVCQSLKTSSVQVF 338
Cdd:cd16722   4 CVICFENEVIAALVPCGHNLFCMEcankiCEKETPSCPVCQTAVTQAIQIH 54

RING finger, HC subclass, found in Arabidopsis thaliana protein XB3 homolog 5 (XBAT35) and similar proteins; XBAT35, also known as ankyrin repeat domain and RING finger-containing protein XBAT35, or RING-type E3 ubiquitin transferase XBAT35, has no E3 ubiquitin-protein ligase activity observed when associated with the E2 enzyme UBC8 in vitro. It contains a typical C3HC4-type RING-HC finger.

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                ....*....|....*....|....*....|....*....|....*....|.
gi 42571929 292 RCKLCNVKNVSVLLVPCRHLSLCKDC-DVFTGV---CPVCQSLKTSSVQVF 338
Cdd:cd23129   4 ECVVCMDAPRDAVCVPCGHVAGCMSClKALMQSsplCPICRAPVRQVIKVY 54

RING finger, HC subclass, found in caspases-8 and -10-associated RING finger protein 2 (CARP-2) and similar proteins; CARP-2, also known as rififylin, caspase regulator CARP2, FYVE-RING finger protein Sakura (Fring), RING finger and FYVE-like domain-containing protein 1, RING finger protein 189 (RNF189), or RING finger protein 34-like, is an endosome-associated E3 ubiquitin-protein ligase that targets internalized receptor interacting kinase (RIP) for proteasome-mediated degradation. It acts as a negative regulator of tumor necrosis factor (TNF)-induced nuclear factor (NF)-kappaB activation. It also regulates the p53 signaling pathway by degrading 14-3-3sigma and stabilizing MDM2. As a caspase regulator, CARP2 does not localize to membranes in the cell and is involved in the negative regulation of apoptosis, specifically targeting two initiator caspases, caspase 8 and caspase 10. CARP2 contains an N-terminal FYVE-like domain and a C-terminal C3HC4-type RING-HC finger domain.

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gi 42571929 293 CKLCNVKNVSVLLVPCRHLSLCKDCDVFTGVCPVCQSLKTSSVQVF 338
Cdd:cd16707   5 CKICMDSPIDCVLLECGHMVTCTKCGKRMSECPICRQYVIRAVHVF 50

Modified RING finger, HC subclass (C4C4-type), found in Saccharomyces cerevisiae amino acid sensor-independent protein Asi1p, Asi3p and similar proteins; Asi1p and Asi3p are inner nuclear membrane proteins that act as negative regulators of SPS (Ssy1-Ptr3-Ssy5)-sensor signaling in yeast. Together with Asi2p, they assemble into an Asi complex that functions in the SPS amino acid sensing pathway involved in degradation of Stp1 and Stp2 transcription factors. Both Asi1p and Asi3p contain five membrane-spanning domains, as well as highly conserved RING fingers at their extreme C termini, which are C4C4-type RING finger motifs whose overall folding is similar to that of the C3HC4-type RING-HC finger.

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gi 42571929 290 GMRCKLCNVKNVSVLLVPCRHLSLCKDCDVFTGV-----CPVCQS 329
Cdd:cd16616   1 DLSCVICKSNPRNIVLWPCRCLALCDDCRLSLAMrgfhtCVCCRR 45

RING finger, HC subclass, found in Dictyostelium discoideum Cbl-like protein A (CblA) and similar proteins; CblA is a Dictyostelium homolog of the Cbl proteins which are multi-domain proteins acting as key negative regulators of various receptor and non-receptor tyrosine kinase signaling. CblA upregulates STATc tyrosine phosphorylation by downregulating PTP3, the protein tyrosine phosphatase responsible for dephosphorylating STATc. STATc is a signal transducer and activator of transcription protein. Like other Cbl proteins, CblA contains a tyrosine-kinase-binding domain (TKB), a proline-rich domain, a C3HC4-type RING-HC finger, and an ubiquitin-associated (UBA) domain. TKB, also known as a phosphotyrosine binding PTB domain, is composed of a four helix-bundle, a Ca2+ binding EF-hand and a highly variant SH2 domain. This family also includes Drosophila melanogaster defense repressor 1 (Dnr1) that was identified as an inhibitor of Dredd activity in the absence of a microbial insult in Drosophila S2 cells. It inhibits the Drosophila initiator caspases Dredd and Dronc. Moreover, Dnr1 acts as a negative regulator of the Imd (immune deficiency) innate immune-response pathway. Its mutations cause neurodegeneration in Drosophila by activating the innate immune response in the brain. Dnr1 contains a FERM N-terminal domain followed by a region rich in glutamine and serine residues, a central FERM domain, and a C-terminal C3HC4-type RING-HC finger.

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                ....*....|....*....|....*....|....*....|....*..
gi 42571929 292 RCKLCNVKNVSVLLVPCRHLSLCKDCDVFTGVCPVCQSLKTSSVQVF 338
Cdd:cd16501   7 LCVVCMDAPIDTVFLECGHLACCRLCSKRLRVCPICRQPISRVVRIF 53

RING finger, HC subclass, found in RNA-binding protein MEX3D; MEX3D, also known as RING finger and KH domain-containing protein 1 (RKHD1), RING finger protein 193 (RNF193), or TINO, is an RNA-binding phosphoprotein that controls the stability of the transcripts coding for the anti-apoptotic protein BCL-2, and negatively regulates BCL-2 in HeLa cells. MEX3D contains two K homology (KH) domains that provide RNA-binding capacity, and a C-terminal C3HC4-type RING-HC finger. Like other MEX-3 family proteins, MEX3D shuttles between the nucleus and the cytoplasm via the CRM1-dependent export pathway.

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                ....*....|....*....|....*....|....*....|....*....|....*....
gi 42571929 285 GMPSTGMRCKLCNVKNVSVLLVPCRHLSLCKDCDVFT-----GVCPVCQSLKTSSVQVF 338
Cdd:cd16723   5 GARKSARECVVCFESEVIAALVPCGHNLFCMECAIRIcgksePECPACHTPATQAIHIF 63

RING finger, HC subclass, found in caspases-8 and -10-associated RING finger protein CARP-1, CARP-2 and similar proteins; The CARP subfamily includes CARP-1 and CARP-2 proteins, both of which are E3 ubiquitin ligases that ubiquitinate apical caspases and target them for proteasome-mediated degradation. As a novel group of caspase regulators with a FYVE-type zinc finger domain, they do not localize to membranes in the cell and are involved in the negative regulation of apoptosis, specifically targeting two initiator caspases, caspase 8, and caspase 10. Moreover, they stabilize MDM2 by inhibiting MDM2 self-ubiquitination, as well as by targeting 14-3-3sigma for degradation. They work together with MDM2 to enhance p53 degradation, thereby inhibiting p53-mediated cell death. CARPs contain an N-terminal FYVE-like domain that can serve as a membrane-targeting or endosome localizing signal and a C-terminal C3HC4-type RING-HC finger domain.

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                ....*....|....*....|....*....|....*....|....*.
gi 42571929 293 CKLCNVKNVSVLLVPCRHLSLCKDCDVFTGVCPVCQSLKTSSVQVF 338
Cdd:cd16500   3 CKICMDAAIDCVLLECGHMVTCTDCGKKLSECPICRQYVVRVVHFF 48