FERM domain C-lobe of E3 ubiquitin ligase myosin regulatory light chain-interacting protein (MYLIP; also called inducible degrader of the LDL receptor, IDOL); MYLIP/IDOL is a regulator of the LDL receptor (LDLR) pathway via the nuclear receptor liver X receptor (LXR). In response to cellular cholesterol loading, the activation of LXR leads to the induction of MYLIP expression. MYLIP stimulates ubiquitination of the LDLR on its cytoplasmic tail, directing its degradation. The LXR-MYLIP-LDLR pathway provides a complementary pathway to sterol regulatory element-binding proteins for the feedback inhibition of cholesterol uptake. MYLIP has an N-terminal FERM domain and in some cases a C-terminal RING domain. The FERM domain has a cloverleaf tripart structure composed of: (1) FERM_N (A-lobe or F1); (2) FERM_M (B-lobe, or F2); and (3) FERM_C (C-lobe or F3). The C-lobe/F3 within the FERM domain is part of the PH domain family. The FERM domain is found in the cytoskeletal-associated proteins such as ezrin, moesin, radixin, 4.1R, and merlin. These proteins provide a link between the membrane and cytoskeleton and are involved in signal transduction pathways. The FERM domain is also found in protein tyrosine phosphatases (PTPs), the tyrosine kinases FAK and JAK, in addition to other proteins involved in signaling. This domain is structurally similar to the PH and PTB domains and consequently is capable of binding to both peptides and phospholipids at different sites.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 530381841   4 YGIEWHSVRDSEGQKLLIGVGPEGISICKDDFSPINRIAYPVVQMATQSGKNVYLTVTKESGNSIVLLFKMISTRAASGL 83
Cdd:cd13195    1 YGVEFFEVRNIEGQKLLIGVGPHGITICNDDFEVIERIPYTAIQMATSSGRVFTLTYLSDDGSVKVLEFKLPSTRAASGL 80

                         90       100       110
                 ....*....|....*....|....*....|.
gi 530381841  84 YRAITETHAFYRCDTVTSAVMMQYSRDLKGH 114
Cdd:cd13195   81 YRAITEKHAFYRCETVRSAVTDQFSRDLKGT 111

FERM domain C-lobe of E3 ubiquitin ligase myosin regulatory light chain-interacting protein (MYLIP; also called inducible degrader of the LDL receptor, IDOL); MYLIP/IDOL is a regulator of the LDL receptor (LDLR) pathway via the nuclear receptor liver X receptor (LXR). In response to cellular cholesterol loading, the activation of LXR leads to the induction of MYLIP expression. MYLIP stimulates ubiquitination of the LDLR on its cytoplasmic tail, directing its degradation. The LXR-MYLIP-LDLR pathway provides a complementary pathway to sterol regulatory element-binding proteins for the feedback inhibition of cholesterol uptake. MYLIP has an N-terminal FERM domain and in some cases a C-terminal RING domain. The FERM domain has a cloverleaf tripart structure composed of: (1) FERM_N (A-lobe or F1); (2) FERM_M (B-lobe, or F2); and (3) FERM_C (C-lobe or F3). The C-lobe/F3 within the FERM domain is part of the PH domain family. The FERM domain is found in the cytoskeletal-associated proteins such as ezrin, moesin, radixin, 4.1R, and merlin. These proteins provide a link between the membrane and cytoskeleton and are involved in signal transduction pathways. The FERM domain is also found in protein tyrosine phosphatases (PTPs), the tyrosine kinases FAK and JAK, in addition to other proteins involved in signaling. This domain is structurally similar to the PH and PTB domains and consequently is capable of binding to both peptides and phospholipids at different sites.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 530381841   4 YGIEWHSVRDSEGQKLLIGVGPEGISICKDDFSPINRIAYPVVQMATQSGKNVYLTVTKESGNSIVLLFKMISTRAASGL 83
Cdd:cd13195    1 YGVEFFEVRNIEGQKLLIGVGPHGITICNDDFEVIERIPYTAIQMATSSGRVFTLTYLSDDGSVKVLEFKLPSTRAASGL 80

                         90       100       110
                 ....*....|....*....|....*....|.
gi 530381841  84 YRAITETHAFYRCDTVTSAVMMQYSRDLKGH 114
Cdd:cd13195   81 YRAITEKHAFYRCETVRSAVTDQFSRDLKGT 111

Zinc finger, C3HC4 type (RING finger);

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 530381841  202 EAMLCMVCCEEEINSTFCPCGHTVCCESCAAQL----QSCPVCRSRVEHV 247
Cdd:pfam13920   1 EDLLCVICLDRPRNVVLLPCGHLCLCEECAERLlrkkKKCPICRQPIESV 50

Uncharacterized conserved protein, contains RING Zn-finger [General function prediction only];

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|...
gi 530381841 201 KEAMLCMVCCEEEINSTFCPCGHTVcCESCAAQL------QSCPVCRSRVEHV 247
Cdd:COG5236   59 EENMNCQICAGSTTYSARYPCGHQI-CHACAVRLralymqKGCPLCRTETEAV 110

FERM domain C-lobe of E3 ubiquitin ligase myosin regulatory light chain-interacting protein (MYLIP; also called inducible degrader of the LDL receptor, IDOL); MYLIP/IDOL is a regulator of the LDL receptor (LDLR) pathway via the nuclear receptor liver X receptor (LXR). In response to cellular cholesterol loading, the activation of LXR leads to the induction of MYLIP expression. MYLIP stimulates ubiquitination of the LDLR on its cytoplasmic tail, directing its degradation. The LXR-MYLIP-LDLR pathway provides a complementary pathway to sterol regulatory element-binding proteins for the feedback inhibition of cholesterol uptake. MYLIP has an N-terminal FERM domain and in some cases a C-terminal RING domain. The FERM domain has a cloverleaf tripart structure composed of: (1) FERM_N (A-lobe or F1); (2) FERM_M (B-lobe, or F2); and (3) FERM_C (C-lobe or F3). The C-lobe/F3 within the FERM domain is part of the PH domain family. The FERM domain is found in the cytoskeletal-associated proteins such as ezrin, moesin, radixin, 4.1R, and merlin. These proteins provide a link between the membrane and cytoskeleton and are involved in signal transduction pathways. The FERM domain is also found in protein tyrosine phosphatases (PTPs), the tyrosine kinases FAK and JAK, in addition to other proteins involved in signaling. This domain is structurally similar to the PH and PTB domains and consequently is capable of binding to both peptides and phospholipids at different sites.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 530381841   4 YGIEWHSVRDSEGQKLLIGVGPEGISICKDDFSPINRIAYPVVQMATQSGKNVYLTVTKESGNSIVLLFKMISTRAASGL 83
Cdd:cd13195    1 YGVEFFEVRNIEGQKLLIGVGPHGITICNDDFEVIERIPYTAIQMATSSGRVFTLTYLSDDGSVKVLEFKLPSTRAASGL 80

                         90       100       110
                 ....*....|....*....|....*....|.
gi 530381841  84 YRAITETHAFYRCDTVTSAVMMQYSRDLKGH 114
Cdd:cd13195   81 YRAITEKHAFYRCETVRSAVTDQFSRDLKGT 111

FERM domain C-lobe of Protein 4.1 family; The protein 4.1 family includes four well-defined members: erythroid protein 4.1 (4.1R), the best known and characterized member, 4.1G (general), 4.1N (neuronal), and 4.1 B (brain). The less well understood 4.1O/FRMD3 is not a true member of this family and is not included in this hierarchy. Besides three highly conserved domains, FERM, SAB (spectrin and actin binding domain) and CTD (C-terminal domain), the proteins from this family contain several unique domains: U1, U2 and U3. FERM domains like other members of the FERM domain superfamily have a cloverleaf architecture with three distinct lobes: (1) FERM_N (A-lobe or F1); (2) FERM_M (B-lobe, or F2); and (3) FERM_C (C-lobe or F3). The C-lobe/F3 within the FERM domain is part of the PH domain family. The brain is a particularly rich source of protein 4.1 isoforms. The various 4.1R, 4.1G, 4.1N, and 4.1B mRNAs are all expressed in distinct patterns within the brain. It is likely that 4.1 proteins play important functional roles in the brain including motor coordination and spatial learning, postmitotic differentiation, and synaptic architecture and function. In addition they are found in nonerythroid, nonneuronal cells where they may play a general structural role in nuclear architecture and/or may interact with splicing factors. The FERM C domain is the third structural domain within the FERM domain. The FERM domain is found in the cytoskeletal-associated proteins such as ezrin, moesin, radixin, 4.1R, and merlin. These proteins provide a link between the membrane and cytoskeleton and are involved in signal transduction pathways. The FERM domain is also found in protein tyrosine phosphatases (PTPs) , the tyrosine kinases FAK and JAK, in addition to other proteins involved in signaling. This domain is structurally similar to the PH and PTB domains and consequently is capable of binding to both peptides and phospholipids at different sites.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 530381841   4 YGIEWHSVRDSEGQKLLIGVGPEGISICKDDFSpINRIAYPVVQMATQSGKNVYLTVTK-ESGNS-IVLLFKMISTRAAS 81
Cdd:cd13184    1 YGVDLHPAKDSEGVDIMLGVCSSGLLVYRDRLR-INRFAWPKVLKISYKRNNFYIKIRPgEFEQYeTTIGFKLPNHRAAK 79

                         90
                 ....*....|....
gi 530381841  82 GLYRAITETHAFYR 95
Cdd:cd13184   80 RLWKVCVEHHTFFR 93

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.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*....
gi 530381841 194 QEKLRKLKEAMLCMVCCEEEINSTFCPCGHTVCCESCAAQLQSCPVCRSRVEHVQHVYL 252
Cdd:cd16714    5 EEKLRRLQEEKLCKICMDRNISIVFIPCGHLVTCKQCAEALDKCPICCTVITFKQKIFM 63

RING finger, HC subclass, found in inhibitor of apoptosis proteins (IAPs); IAPs are frequently overexpressed in cancer and associated with tumor cell survival, chemoresistance, disease progression, and poor prognosis. They function primarily as negative regulators of cell death. They regulate caspases and apoptosis through the inhibition of specific members of the caspase family of cysteine proteases. In addition, IAPs has been implicated in a multitude of other cellular processes, including inflammatory signalling and immunity, mitogenic kinase signalling, proliferation and mitosis, as well as cell invasion and metastasis. IAPs in this family includes cellular inhibitor of apoptosis protein c-IAP1 (BIRC2) and c-IAP2 (BIRC3), XIAP (BIRC4), BIRC7, and BIRC8, all of which 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), and a C3HC4-type RING-HC finger at the carboxyl terminus that is required for ubiquitin ligase activity. The UBA domain is only absent in mammalian homologs of BIRC7. Moreover, c-IAPs contains an additional caspase activation and recruitment domain (CARD) between the UBA and C3HC4-type RING-HC domains. The CARD domain may serve as a protein interaction surface.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|
gi 530381841 203 AMLCMVCCEEEINSTFCPCGHTVCCESCAAQLQSCPVCRS 242
Cdd:cd16510    1 EKLCKICMDREVNIVFLPCGHLVTCAQCAASLRKCPICRT 40

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.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*..
gi 530381841 205 LCMVCCEEEINSTFCPCGHTVCCESCAAQLQSCPVCRSRVEHVQHVY 251
Cdd:cd16500    2 LCKICMDAAIDCVLLECGHMVTCTDCGKKLSECPICRQYVVRVVHFF 48

Modified RING finger, HC subclass (C3HC5-type), found in neuralized-like protein NEURL1A, NEURL1B, and similar proteins; This subfamily includes Drosophila neuralized (D-neu) protein, and its two mammalian homologs, NEURL1A and NEURL1B. D-neu is a regulator of the developmentally important Notch signaling pathway. NEURL1A, also known as NEURL1, NEU, neuralized 1, or RING finger protein 67 (RNF67), is a mammalian homolog of D-neu. It functions as an E3 ubiquitin-protein ligase that directly interacts with and monoubiquitinates cytoplasmic polyadenylation element-binding protein 3 (CPEB3), an RNA binding protein and a translational regulator of local protein synthesis, which facilitates hippocampal plasticity and hippocampal-dependent memory storage. It also acts as a potential tumor suppressor that causes apoptosis and downregulates Notch target genes in medulloblastoma. NEURL1B, also known as neuralized-2 (NEUR2) or neuralized-like protein 3, is another mammalian homolog of D-neu protein. It functions as an E3 ubiquitin-protein ligase that interacts with and ubiquitinates Delta. Thus, it plays a role in the endocytic pathways for Notch signaling by working cooperatively with another E3 ligase, Mind bomb-1 (Mib1), in Delta endocytosis to hepatocyte growth factor-regulated tyrosine kinase substrate (Hrs)-positive vesicles. Members of this subfamily contain two neuralized homology regions (NHRs) responsible for Neural-ligand interactions and a modified C3HC5-type RING-HC finger required for ubiquitin ligase activity. The C3HC5-type RING-HC finger is distinguished from typical C3HC4-type RING-HC finger due to the existence of the additional cysteine residue in the middle portion of the RING finger domain.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|
gi 530381841 206 CMVCCEEEINSTFCPCGHTVCCESCAAQLQ----SCPVCRSRVEHVQHVY 251
Cdd:cd16647    4 CVICYERPVDTVLYRCGHMCMCYDCALQLKrrggSCPICRAPIKDVIKIY 53

RING finger, HC subclass, found in leucine-rich repeat and sterile alpha motif-containing protein 1 (LRSAM1) and similar proteins; LRSAM1, also known as Tsg101-associated ligase (TAL), or RIFLE, is an E3 ubiquitin-protein ligase that physically associates with, and selectively ubiquitylates, Tsg101, an E2-like molecule that regulates vesicular trafficking processes in yeast and mammals. It regulates a Tsg101-associated complex responsible for the sorting of cargo into cytoplasm-containing vesicles that bud at the multivesicular body and at the plasma membrane. LRSAM1 is a multidomain protein containing an N-terminal leucine-rich repeat (LRR), followed by several recognizable motifs, including an ezrin-radixin-moezin (ERM) domain, a coiled-coil (CC) region, a SAM domain, and a C-terminal C3HC4-type RING-HC finger domain.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|..
gi 530381841 206 CMVCCEEEINSTFCPCGHTVCCESCAAQLQSCPVCRSRVEHV 247
Cdd:cd16515    4 CVVCMDAESQVIFLPCGHVCCCQTCSSSLSTCPLCRADITQR 45

FERM domain C-lobe of FERM domain-containing protein 3 and 5 (FRMD3 and 5); FRMD3 (also called Band 4.1-like protein 4O/4.1O though it is not a true member of that family) is a novel putative tumor suppressor gene that is implicated in the origin and progression of lung cancer. In humans there are 5 isoforms that are produced by alternative splicing. Less is known about FRMD5, though there are 2 isoforms of the human protein are produced by alternative splicing. Both FRMD3 and FRMD5 contain a N-terminal FERM domain, followed by a FERM adjacent (FA) domain, and 4.1 protein C-terminal domain (CTD). The FERM domain has a cloverleaf tripart structure composed of: (1) FERM_N (A-lobe or F1); (2) FERM_M (B-lobe, or F2); and (3) FERM_C (C-lobe or F3). The C-lobe/F3 within the FERM domain is part of the PH domain family. The FERM domain is found in the cytoskeletal-associated proteins such as ezrin, moesin, radixin, 4.1R, and merlin. These proteins provide a link between the membrane and cytoskeleton and are involved in signal transduction pathways. The FERM domain is also found in protein tyrosine phosphatases (PTPs), the tyrosine kinases FAK and JAK, in addition to other proteins involved in signaling. This domain is structurally similar to the PH and PTB domains and consequently is capable of binding to both peptides and phospholipids at different sites.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 530381841   1 MENYGIEWHSVRDSEGQKLLIGVGPEGISICKDDfSPINRIAYPVVQMATQSGKNVYLTVTKESGNSIVLLFKMISTRAA 80
Cdd:cd13192   12 LETYGVDPHPVKDHRGNQLYLGFTHTGIVTFQGG-KRVHHFRWNDITKFNYEGKMFILHVMQKEEKKHTLGFKCPTPAAC 90

                         90
                 ....*....|....*
gi 530381841  81 SGLYRAITETHAFYR 95
Cdd:cd13192   91 KHLWKCAVEQQAFYT 105

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.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|.
gi 530381841 206 CMVCCEEEINSTFCPCGHTVCCESCAAQL-----QSCPVCRSRVEHVQHVY 251
Cdd:cd16518    3 CVVCFESEVVAALVPCGHNLFCMECANRIceksdPECPVCHTPVTQAIRIF 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.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|.
gi 530381841 206 CMVCCEEEINSTFCPCGHTVCCESCAAQL-----QSCPVCRSRVEHVQHVY 251
Cdd:cd16723   13 CVVCFESEVIAALVPCGHNLFCMECAIRIcgksePECPACHTPATQAIHIF 63

RING finger, HC subclass, found in Arabidopsis thaliana MND1-interacting protein 1 (MIP1) and similar proteins; This subfamily includes Arabidopsis thaliana MIP1, RING finger protein 4 (RF4) and RING finger protein 298 (RF298). MIP1 interacts with MND1, HOP2 and XRI1. RF4 and RF298 are putative E3 ubiquitin-protein ligase that may mediate E2-dependent protein ubiquitination. Members of this subfamily contain a typical C3HC4-type RING-HC finger.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*
gi 530381841 206 CMVCCEEEINSTFCPCGHTVCCESCAAQLQS-----CPVCRSRVE 245
Cdd:cd23128    6 CVMCMEEERSVVFLPCAHQVVCSGCNDLHEKkgmreCPSCRGEIQ 50

FERM C-terminal PH-like domain;

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 530381841   13 DSEGQKLLIGVGPEGISICKDDFSPINRIAYPVVQMATQSGKNVYLTVTKESGnSIVLLFKMISTRAASGLYRAITETHA 92
Cdd:pfam09380   1 DKEGTDLWLGVSAKGILVYEDNNKILNLFPWREIRKISFKRKKFLIKLRDKSS-EETLGFYTESSRACKYLWKLCVEQHT 79

                  ....
gi 530381841   93 FYRC 96
Cdd:pfam09380  80 FFRL 83

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.

                         10        20        30
                 ....*....|....*....|....*....|....*..
gi 530381841 205 LCMVCCEEEINSTFCPCGHTVCCESCAAQLQSCPVCR 241
Cdd:cd16787    2 DCVVCQNAPVNRVLLPCRHACVCDECFKRLQRCPMCR 38

RING finger, HC subclass, found in neuralized-like protein 3 (NEURL3) and similar proteins; NEURL3, also known as lung-inducible neuralized-related C3HC4 RING domain protein (LINCR), is a novel inflammation-induced E3 ubiquitin-protein ligase encoded by LINCR, a glucocorticoid-attenuated response gene induced in the lung during endotoxemia. It is expressed in alveolar epithelial type II cells, preferentially interacts with the ubiquitin-conjugating enzyme UbcH6, and generates polyubiquitin chains linked via non-canonical lysine residues. Overexpression of NEURL3 in the developing lung epithelium inhibits distal differentiation and induces cystic changes in the Notch signaling pathway. NEURL3 contains an N-terminal neuralized homology repeat (NHR) domain similar to the SPRY (SPla and the RYanodine receptor) domain and a C-terminal C3HC4-type RING-HC finger.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*.
gi 530381841 206 CMVCCEEEINSTFCPCGHTVCCESCAAQLQS----CPVCRSRVEHV 247
Cdd:cd16552    4 CAICFHHTANTRLVPCGHSHFCGSCAWHIFRdtarCPVCRWQIEEV 49

HC subclass of RING (RING-HC) finger and its variants; The RING finger is a specialized type of Zn-finger of 40 to 60 residues that binds two atoms of zinc. It is defined by the "cross-brace" motif that chelates zinc atoms by eight amino acid residues, typically Cys or His, arranged in a characteristic spacing. Canonical RING motifs have been categorized into two major subclasses, RING-HC (C3HC4-type) and RING-H2 (C3H2C3-type), according to their Cys/His content. There are also many variants of RING fingers. Some have a different Cys/His pattern. Some lack a single Cys or His residue at typical Zn ligand positions, especially, the fourth or eighth zinc ligand is prevalently exchanged for an Asp, which can chelate Zn in a RING finger as well. This family corresponds to the HC subclass of RING (RING-HC) fingers that are characterized by containing C3HC4-type canonical RING-HC fingers or noncanonical RING-HC finger variants, including C4C4-, C3HC3D-, C2H2C4-, and C3HC5-type modified RING-HC fingers. The canonical RING-HC finger has been defined as C-X2-C-X(9-39)-C-X(1-3)-H-X(2-3)-C-X2-C-X(4-48)-C-X2-C. It binds two Zn ions in a unique "cross-brace" arrangement, which distinguishes it from tandem zinc fingers and other similar motifs. RING-HC fingers can be found in a group of diverse proteins with a variety of cellular functions, including oncogenesis, development, viral replication, signal transduction, the cell cycle, and apoptosis. Many of them are ubiquitin-protein ligases (E3s) that serve as scaffolds for binding to ubiquitin-conjugating enzymes (E2s, also referred to as ubiquitin carrier proteins or UBCs) in close proximity to substrate proteins, which enables efficient transfer of ubiquitin from E2 to the substrates.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|..
gi 530381841 204 MLCMVCCEEEINSTFCPCGHtVCCESCAAQL-----QSCPVC 240
Cdd:cd16449    1 LECPICLERLKDPVLLPCGH-VFCRECIRRLlesgsIKCPIC 41

Modified RING finger, HC subclass (C3HC5-type), found in mitochondrial-anchored protein ligase (MAPL) and similar proteins; MAPL, also known as MULAN, mitochondrial ubiquitin ligase activator of NFKB 1, E3 SUMO-protein ligase MUL1, E3 ubiquitin-protein ligase MUL1, growth inhibition and death E3 ligase (GIDE), putative NF-kappa-B-activating protein 266, or RING finger protein 218 (RNF218), is a multifunctional mitochondrial outer membrane protein involved in several processes specific to metazoan (multicellular animal) cells, such as NF-kappaB activation, innate immunity and antiviral signaling, suppression of PINK1/parkin defects, mitophagy in skeletal muscle, and caspase-dependent apoptosis. MAPL contains a unique BAM (beside a membrane)/GIDE (growth inhibition death E3 ligase) domain and a C-terminal modified cytosolic C3HC5-type RING-HC finger which is distinguished from typical C3HC4-type RING-HC finger due to the existence of the additional cysteine residue in the middle portion of the RING finger domain.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*....
gi 530381841 206 CMVCCEEEINSTFCPCGHTVCCESCAAQLQS---CPVCRSRVEHVQHVY 251
Cdd:cd16648    4 CVICLSNPRSCVFLECGHVCSCIECYEALPSpkkCPICRSFIKRVVPLY 52

first RING finger, HC subclass, found in mind bomb 2 (MIB2) and similar proteins; MIB2, also known as novel zinc finger protein (Novelzin), putative NF-kappa-B-activating protein 002N, skeletrophin, or zinc finger ZZ type with ankyrin repeat domain protein 1, is a large, multi-domain E3 ubiquitin-protein ligase that promotes ubiquitination of the cytoplasmic tails of Notch ligands. It promotes Delta ubiquitylation and endocytosis in Notch activation. Overexpression of MIB2 activates NF-kappaB and interferon-stimulated response element (ISRE) reporter activity. Moreover, MIB2 acts as a novel component of the activated B-cell CLL/lymphoma 10 (BCL10) complex and controls BCL10-dependent NF-kappaB activation. It also functions as a founder myoblast-specific protein that regulates myoblast fusion and muscle stability. MIB2 contains an MZM region with two Mib-Herc2 domains flanking a ZZ zinc finger, a REP region including two tandem Mib repeats, an ANK region that spans ankyrin repeats, and a RNG region consisting of two C3HC4-type RING-HC fingers. This model corresponds to the first RING-HC finger.

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gi 530381841 206 CMVCCEEEINSTFCPCGHTVCCESCAAQLQSCPVC 240
Cdd:cd16726    3 CLVCSELAALVRFEPCQHSIVCEECARRMKKCIKC 37

Modified RING finger, HC subclass (C3HC5-type), found in neuralized-like protein 1B (NEURL1B); NEURL1B, also known as neuralized-2 (NEUR2) or neuralized-like protein 3, is a mammalian homolog of the Drosophila neuralized (D-neu) protein. It functions as an E3 ubiquitin-protein ligase that interacts with and ubiquitinates Delta. Thus, it plays a role in the endocytic pathways for Notch signaling through working cooperatively with another E3 ligase, Mind bomb-1 (Mib1), in Delta endocytosis to hepatocyte growth factor-regulated tyrosine kinase substrate (Hrs)-positive vesicles. NEURL1B contains two neuralized homology regions (NHRs) responsible for Neural-ligand interactions and a modified C3HC5-type RING-HC finger required for ubiquitin ligase activity. The C3HC5-type RING-HC finger is distinguished from typical C3HC4-type 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 530381841 206 CMVCCEEEINSTFCPCGHTVCCESCAAQLQS-----CPVCRSRVEHVQHVYLP 253
Cdd:cd16786    5 CTVCFDSEVDTVIYTCGHMCLCNSCGLKLKRqinacCPICRRVIKDVIKIYRP 57

RING finger, HC subclass, found in mind bomb MIB1, MIB2, RGLG1, RGLG2, and similar proteins; MIBs are large, multi-domain E3 ubiquitin-protein ligases that promote ubiquitination of the cytoplasmic tails of Notch ligands. They are also responsible for TBK1 K63-linked ubiquitination and activation, promoting interferon production and controlling antiviral immunity. Moreover, MIBs selectively control responses to cytosolic RNA and regulate type I interferon transcription. Both MIB1 and MIB2 have similar domain architectures, which consist of two Mib-Herc2 domains flanking a ZZ zinc finger, a REP region including two tandem Mib repeats, an ANK region that spans ankyrin repeats, and a RNG region, where MIB1 and MIB2 contain three and two C3HC4-type RING-HC fingers, respectively. This model corresponds to the third RING-HC finger of MIB1, as well as the second RING-HC finger of MIB2. In addition to MIB1 and MIB2, the RING-HC fingers of RING domain ligase RGLG1, RGLG2 and similar proteins from plant are also included in this model. RGLG1 is a ubiquitously expressed E3 ubiquitin-protein ligase that interacts with UBC13 and, together with UBC13, catalyzes the formation of K63-linked polyubiquitin chains, which is involved in DNA damage repair. RGLG1 mediates the formation of canonical, K48-linked polyubiquitin chains that target proteins for degradation. It also regulates apical dominance by acting on the auxin transport proteins abundance. RGLG1 has overlapping functions with its closest sequelog, RGLG2. They both function as RING E3 ligases that interact with ethylene response factor 53 (ERF53) in the nucleus and negatively regulate the plant drought stress response. All RGLG proteins contain a Von Willebrand factor type A (vWA) domain and a C3HC4-type RING-HC finger.

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gi 530381841 205 LCMVCCEEEINSTFCpCGHTVCCEsCAAQLQSCPVCR 241
Cdd:cd16520    2 LCPICMERKKNVVFL-CGHGTCQK-CAEKLKKCPICR 36

Modified RING finger, HC subclass (C3HC5-type), found in RING finger proteins, RNF26, RNF197 (CGRRF1), RNF156 (MGRN1), RNF157 and similar proteins; This subfamily corresponds to a group of RING finger proteins containing a 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. Cell growth regulator with RING finger domain protein 1 (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. RNF26 is an E3 ubiquitin ligase that temporally regulates virus-triggered type I interferon induction by increasing the stability of Mediator of IRF3 activation, MITA, also known as STING, through K11-linked polyubiquitination after viral infection and promoting degradation of IRF3, another important component required for virus-triggered interferon induction. Mahogunin ring finger-1 (MGRN1), also known as RING finger protein 156 (RNF156), is a cytosolic E3 ubiquitin-protein ligase that inhibits signaling through the G protein-coupled melanocortin receptors-1 (MC1R), -2 (MC2R) and -4 (MC4R) via ubiquitylation-dependent and -independent processes. It suppresses chaperone-associated misfolded protein aggregation and toxicity. RNF157 is a cytoplasmic E3 ubiquitin ligase predominantly expressed in the brain. It is a homolog of the E3 ligase MGRN1. In cultured neurons, it promotes neuronal survival in an E3 ligase-dependent manner. In contrast, it supports growth and maintenance of dendrites independent of its E3 ligase activity. RNF157 interacts with and ubiquitinates the adaptor protein APBB1 (amyloid beta precursor protein-binding, family B, member 1 or Fe65), which regulates neuronal survival, but not dendritic growth downstream of RNF157. The nuclear localization of APBB1 together with its interaction partner RNA-binding protein SART3 (squamous cell carcinoma antigen recognized by T cells 3 or Tip110) is crucial to trigger apoptosis.

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gi 530381841 205 LCMVCCEEEINSTFCPCGHTVCCESCAAQLQS--CPVCR 241
Cdd:cd16649    2 LCVVCLENPASVLLLPCRHLCLCEVCAKGLRGktCPICR 40

Modified RING finger, HC subclass (C2H2C4-type), found in E3 ubiquitin-protein ligase MDM2, protein MDM4 and similar proteins; MDM2 (also known as HDM2) and MDM4 (also known as MDMX or HDMX) are the primary p53 tumor suppressor negative regulators. They have non-redundant roles in the regulation of p53. MDM2 mainly functions to control p53 stability, while MDM4 controls p53 transcriptional activity. Both MDM2 and MDM4 contain an N-terminal p53-binding domain, a RanBP2-type zinc finger (zf-RanBP2) domain near the central acidic region, and a C-terminal modified C2H2C4-type RING-HC finger. Mdm2 can form homo-oligomers through its RING domain and displays E3 ubiquitin ligase activity that catalyzes the attachment of ubiquitin to p53 as an essential step in the regulation of its levels in cells. Despite its RING domain and structural similarity with MDM2, MDM4 does not homo-oligomerize and lacks ubiquitin-ligase function, but inhibits the transcriptional activity of p53. In addition, both their RING domains are responsible for the hetero-oligomerization, which is crucial for the suppression of P53 activity during embryonic development and the recruitment of E2 ubiquitin-conjugating enzymes. Moreover, MDM2 and MDM4 can be phosphorylated and destabilized in response to DNA damage stress. In response to ribosomal stress, MDM2-mediated p53 ubiquitination and degradation can be inhibited through the interaction with ribosomal proteins L5, L11, and L23. However, MDM4 is not bound to ribosomal proteins, suggesting its different response to regulation by small basic proteins such as ribosomal proteins and ARF.

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gi 530381841 205 LCMVCCEEEINSTFC--PCGHTVCCESCAAQL----QSCPVCRSRVEHV 247
Cdd:cd16646    2 LCVICLSRPRTAAIVhgKTGHQVACYTCAKKLkrrgKPCPVCRRPIQNV 50

RING finger, HC subclass, found in RING finger protein unkempt-like (UNKL) and similar proteins; 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. It shows high sequence similarity with RING finger protein unkempt (UNK), which is a metazoan-specific zinc finger protein enriched in embryonic brains, and may play a broad regulatory role during the formation of the central nervous system (CNS). UNKL contains several CCCH-type zinc fingers at the N-terminus, and a C3HC4-type RING-HC finger at its C-terminus.

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gi 530381841 206 CMVCCEEEINSTFCPCGHTVCCESCAAQLQSCPVCRSRV 244
Cdd:cd16772    3 CIVCQERDRSIVLQPCQHYVLCEHCAASKPECPYCKTKI 41

Modified RING finger, HC subclass (C3HC5-type), found in mahogunin RING finger protein 1 (MGRN1), RING finger protein 157 (RNF157) and similar proteins; MGRN1, also known as RING finger protein 156 (RNF156), is a cytosolic E3 ubiquitin-protein ligase that inhibits signaling through the G protein-coupled melanocortin receptors-1 (MC1R), -2 (MC2R) and -4 (MC4R) via ubiquitylation-dependent and -independent processes. It suppresses chaperone-associated misfolded protein aggregation and toxicity. MGRN1 interacts with cytosolic prion proteins (PrPs) that are linked with neurodegeneration. It also interacts with expanded polyglutamine proteins, and suppresses misfolded polyglutamine aggregation and cytotoxicity. Moreover, MGRN1 inhibits melanocortin receptor signaling by competition with Galphas, suggesting a novel pathway for melanocortin signaling from the cell surface to the nucleus. MGRN1 also interacts with and ubiquitylates TSG101, a key component of the endosomal sorting complex required for transport (ESCRT)-I, and regulates endosomal trafficking. A null mutation in the gene encoding MGRN1 causes spongiform neurodegeneration, suggesting a link between dysregulation of endosomal trafficking and spongiform neurodegeneration. RNF157 is a cytoplasmic E3 ubiquitin ligase predominantly expressed in the brain. It is a homolog of the E3 ligase mahogunin ring finger-1 (MGRN1). In cultured neurons, it promotes neuronal survival in an E3 ligase-dependent manner. In contrast, it supports growth and maintenance of dendrites independent of its E3 ligase activity. RNF157 interacts with and ubiquitinates the adaptor protein APBB1 (amyloid beta precursor protein-binding, family B, member 1 or Fe65), which regulates neuronal survival, but not dendritic growth downstream of RNF157. The nuclear localization of APBB1 together with its interaction partner RNA-binding protein SART3 (squamous cell carcinoma antigen recognized by T cells 3 or Tip110) is crucial to trigger apoptosis. Both MGRN1 and RNF157 contain a modified C3HC5-type RING-HC finger, and a functionally uncharacterized region, known as domain associated with RING2 (DAR2), N-terminal to the RING finger. The C3HC5-type RING-HC finger 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 530381841 205 LCMVCCEEEINSTFCPCGHTVCCESCAAQLQ----SCPVCR 241
Cdd:cd16789    2 ECVICLSDPRDTAVLPCRHLCLCSDCAEVLRyqsnKCPICR 42

Modified RING finger, HC subclass (C3HC5-type), found in RING finger protein 26 (RNF26) and similar proteins; RNF26 is an E3 ubiquitin ligase that temporally regulates virus-triggered type I interferon induction by increasing the stability of Mediator of IRF3 activation, MITA, also known as STING, through K11-linked polyubiquitination of MITA after viral infection, and promoting the degradation of IRF3, another important component required for virus-triggered interferon induction. Although RNF26 substrates of ubiquitination remain unclear at present, RNF26 upregulation in gastric cancer might be implicated in carcinogenesis through dysregulation of growth regulators. RNF26 contains an N-terminal leucine zipper domain and 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 530381841 205 LCMVCCEEEINSTFCPCGHTVCCESCAAQL-------QSCPVCRSRVEHVQHVY 251
Cdd:cd16788    7 KCVICQDQSKTVLILPCRHMCLCRQCANILlqqpvyrRNCPLCRTMILQTLDVY 60

RING-finger-containing E3 ubiquitin ligase [Posttranslational modification, protein turnover, chaperones];

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gi 530381841 188 QQTRVLQEKLRKlkeamlCMVCCEEEINSTFCPCGHTVCC-----ESCAAQLQSCPVCRSRV 244
Cdd:COG5574  206 NGLPFIPLADYK------CFLCLEEPEVPSCTPCGHLFCLsclliSWTKKKYEFCPLCRAKV 261