Src homology 2 (SH2) domain found in the Cbl-b TKB domain; SH2 found in the Cbl-b TKB domain. The Cbl (for Casitas B-lineage lymphoma) family of E3 ubiquitin ligases contains three members Cbl, Cbl-b and Cbl-c. The founding member Cbl was discovered first as the oncogenic protein v-Cbl, a Gag-fusion transforming protein of Cas NS-1 retrovirus, which causes pre- and pro-B lymphomas in mice. The N-terminus of the Cbl proteins is composed of a tyrosine kinase-binding (TKB) domain, also called phosphotyrosine binding (PTB) domain, a short linker region and the RING-type zinc finger. In addition, Cbl and Cbl-b contain a leucine zipper motif and a proline-rich domain in the C-terminus. The TKB domain consists of a four-helix bundle (4H), a calcium-binding EF hand and a divergent SH2 domain. Cbl-b plays a role in early hematopoietic development and is a negative regulator of T-cell receptor, B-cell receptor and high affinity immunoglobulin epsilon receptor signal transduction pathways. It also negatively regulates insulin-like growth factor 1 signaling during muscle atrophy caused by unloading and is involved in EGFR ubiquitination and internalization. Diseases associated with defects in Cbl-b include: multiple sclerosis, autoimmune diseases, including type 1 diabetes, and a craniofacial phenotype. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217346635 248 RNWNFLAVTHPGYMAFLTYDEVKARLQKYSTKPGSYIFRLSCTRLGQWAIGYVTGDGNILQTIPHNKPLFQALIDGSREG 327
Cdd:cd09920     1 RNWQVLAVTHPGYMAFLTYDEVKARLQKFRDKPGSYVFRLSCTRLGQWAIGYVTADGKILQTIPQNKSLCQALIDGSREG 80

                          90
                  ....*....|....*..
gi 2217346635 328 FYLYPDGRSYNPDLTGL 344
Cdd:cd09920    81 FYLYPDGRLDNPDLSGA 97

RING finger, HC subclass, found in E3 ubiquitin-protein ligase Cbl-b and similar proteins; Cbl-b, also known as Casitas B-lineage lymphoma proto-oncogene b, RING finger protein 56 (RNF56), SH3-binding protein Cbl-b, or signal transduction protein Cbl-b, has been identified as a regulator of antigen-specific, T cell-intrinsic, peripheral immune tolerance, a state also known as clonal anergy. It may inhibit activation of the p85 subunit of phosphoinositide 3-kinase (PI3K), protein kinase C-theta (PKC-theta), and phospholipase C-gamma1 (PLC-gamma1) and negatively regulates T-cell receptor-induced transcription factor nuclear factor kappaB (NF-kappaB) activation. In addition, Cbl-b may target multiple signaling molecules involved in transforming growth factor (TGF)-beta-mediated transactivation pathways. Cbl-b contains a tyrosine-kinase-binding domain (TKB, also known as the phosphotyrosine binding PTB domain, is composed of a four helix-bundle, a Ca2+ binding EF-hand and a highly variant SH2 domain), a proline rich domain, a nuclear localization signal, a C3HC4-type RING-HC finger and an ubiquitin-associated (UBA) domain.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 2217346635 351 DHIKVTQEQYELYCEMGSTFQLCKICAENDKDVKIEPCGHLMCTSCLTAWQESDGQGCPFCRCEIKGTEPIIVDPF 426
Cdd:cd16709     1 DHIKVTQEQYELYCEMGSTFQLCKICAENDKDVKIEPCGHLMCTSCLTAWQESDGQGCPFCRCEIKGTEPIIVDPF 76

Src homology 2 (SH2) domain found in the Cbl-b TKB domain; SH2 found in the Cbl-b TKB domain. The Cbl (for Casitas B-lineage lymphoma) family of E3 ubiquitin ligases contains three members Cbl, Cbl-b and Cbl-c. The founding member Cbl was discovered first as the oncogenic protein v-Cbl, a Gag-fusion transforming protein of Cas NS-1 retrovirus, which causes pre- and pro-B lymphomas in mice. The N-terminus of the Cbl proteins is composed of a tyrosine kinase-binding (TKB) domain, also called phosphotyrosine binding (PTB) domain, a short linker region and the RING-type zinc finger. In addition, Cbl and Cbl-b contain a leucine zipper motif and a proline-rich domain in the C-terminus. The TKB domain consists of a four-helix bundle (4H), a calcium-binding EF hand and a divergent SH2 domain. Cbl-b plays a role in early hematopoietic development and is a negative regulator of T-cell receptor, B-cell receptor and high affinity immunoglobulin epsilon receptor signal transduction pathways. It also negatively regulates insulin-like growth factor 1 signaling during muscle atrophy caused by unloading and is involved in EGFR ubiquitination and internalization. Diseases associated with defects in Cbl-b include: multiple sclerosis, autoimmune diseases, including type 1 diabetes, and a craniofacial phenotype. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217346635 248 RNWNFLAVTHPGYMAFLTYDEVKARLQKYSTKPGSYIFRLSCTRLGQWAIGYVTGDGNILQTIPHNKPLFQALIDGSREG 327
Cdd:cd09920     1 RNWQVLAVTHPGYMAFLTYDEVKARLQKFRDKPGSYVFRLSCTRLGQWAIGYVTADGKILQTIPQNKSLCQALIDGSREG 80

                          90
                  ....*....|....*..
gi 2217346635 328 FYLYPDGRSYNPDLTGL 344
Cdd:cd09920    81 FYLYPDGRLDNPDLSGA 97

CBL proto-oncogene N-terminus, EF hand-like domain; Cbl is an adaptor protein that binds EGF receptors (or other tyrosine kinases) and SH3 domains, functioning as a negative regulator of many signaling pathways. The N-terminal domain is evolutionarily conserved, and is known to bind to phosphorylated tyrosine residues. The so called N-terminal domain is actually 3 structural domains, of which this is the central EF hand domain.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217346635 171 FRITKADAAEFWRKFFGDKTIVPWKVFRQCLHEVHQISSGLEAMALKSTIDLTCNDYISVFEFDIFTRLFQPWGSILRNW 250
Cdd:pfam02761   1 FRITKSEAAEFWKKSFGKRTIVPWKEFRTALQQVHGIESGLEAMALKSTIDLTCNDHISIFEFDVFTRLFQPWSTLLRNW 80

                  ....
gi 2217346635 251 NFLA 254
Cdd:pfam02761  81 NLLA 84

Prokaryotic RING finger family 4; RING finger family domain found sporadically in bacteria. The finger is fused to an N-terminal alpha-helical domain, ROT/Trove-like repeats and a C-terminal TerD domain. The architecture suggests a possible role in an RNA-processing complex.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*....
gi 2217346635 373 CKICAENDKDVKIEPCGHLMCTSCltaWQESDGQGCPFCRCEIKGTEPI 421
Cdd:pfam14447   1 CVLCGRNGTVHALIPCGHLVCRDC---FDGSDFSACPICRRRIDADDPF 46

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

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|.
gi 2217346635 373 CKICAENDKDVKIEPCGHLMCTSCL-TAWQESDGQGCPFCR 412
Cdd:COG5574   218 CFLCLEEPEVPSCTPCGHLFCLSCLlISWTKKKYEFCPLCR 258

Src homology 2 (SH2) domain found in the Cbl-b TKB domain; SH2 found in the Cbl-b TKB domain. The Cbl (for Casitas B-lineage lymphoma) family of E3 ubiquitin ligases contains three members Cbl, Cbl-b and Cbl-c. The founding member Cbl was discovered first as the oncogenic protein v-Cbl, a Gag-fusion transforming protein of Cas NS-1 retrovirus, which causes pre- and pro-B lymphomas in mice. The N-terminus of the Cbl proteins is composed of a tyrosine kinase-binding (TKB) domain, also called phosphotyrosine binding (PTB) domain, a short linker region and the RING-type zinc finger. In addition, Cbl and Cbl-b contain a leucine zipper motif and a proline-rich domain in the C-terminus. The TKB domain consists of a four-helix bundle (4H), a calcium-binding EF hand and a divergent SH2 domain. Cbl-b plays a role in early hematopoietic development and is a negative regulator of T-cell receptor, B-cell receptor and high affinity immunoglobulin epsilon receptor signal transduction pathways. It also negatively regulates insulin-like growth factor 1 signaling during muscle atrophy caused by unloading and is involved in EGFR ubiquitination and internalization. Diseases associated with defects in Cbl-b include: multiple sclerosis, autoimmune diseases, including type 1 diabetes, and a craniofacial phenotype. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217346635 248 RNWNFLAVTHPGYMAFLTYDEVKARLQKYSTKPGSYIFRLSCTRLGQWAIGYVTGDGNILQTIPHNKPLFQALIDGSREG 327
Cdd:cd09920     1 RNWQVLAVTHPGYMAFLTYDEVKARLQKFRDKPGSYVFRLSCTRLGQWAIGYVTADGKILQTIPQNKSLCQALIDGSREG 80

                          90
                  ....*....|....*..
gi 2217346635 328 FYLYPDGRSYNPDLTGL 344
Cdd:cd09920    81 FYLYPDGRLDNPDLSGA 97

CBL proto-oncogene N-terminus, EF hand-like domain; Cbl is an adaptor protein that binds EGF receptors (or other tyrosine kinases) and SH3 domains, functioning as a negative regulator of many signaling pathways. The N-terminal domain is evolutionarily conserved, and is known to bind to phosphorylated tyrosine residues. The so called N-terminal domain is actually 3 structural domains, of which this is the central EF hand domain.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217346635 171 FRITKADAAEFWRKFFGDKTIVPWKVFRQCLHEVHQISSGLEAMALKSTIDLTCNDYISVFEFDIFTRLFQPWGSILRNW 250
Cdd:pfam02761   1 FRITKSEAAEFWKKSFGKRTIVPWKEFRTALQQVHGIESGLEAMALKSTIDLTCNDHISIFEFDVFTRLFQPWSTLLRNW 80

                  ....
gi 2217346635 251 NFLA 254
Cdd:pfam02761  81 NLLA 84

RING finger, HC subclass, found in E3 ubiquitin-protein ligase Cbl and similar proteins; Cbl, also known as Casitas B-lineage lymphoma proto-oncogene, proto-oncogene c-Cbl, RING finger protein 55 (RNF55), or signal transduction protein Cbl, is a multi-domain protein that acts as a key negative regulator of various receptor and non-receptor tyrosine kinase signaling. It contains a tyrosine kinase-binding domain (TKB, also known as the phosphotyrosine binding PTB domain, composed of a four helix-bundle, a Ca2+ binding EF-hand and a highly variant SH2 domain), a proline-rich domain, a C3HC4-type RING-HC finger, and an ubiquitin-associated (UBA) domain. TKB is responsible for the interactions with many tyrosine kinases, such as the colony-stimulating factor-1 (CSF-1) receptor, Syk/ZAP-70, and Src-family of protein tyrosine kinases. The proline-rich domain can recruit proteins with a SH3 domain. Moreover, Cbl functions as an E3 ubiquitin ligase that can bind ubiquitin-conjugating enzymes (E2s) through the RING-HC finger.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 2217346635 350 HDHIKVTQEQYELYCEMGSTFQLCKICAENDKDVKIEPCGHLMCTSCLTAWQESDGQGCPFCRCEIKGTEPIIVDPF 426
Cdd:cd16708     1 QDHIKVTQEQYELYCEMGSTFQLCKICAENDKDVKIEPCGHLMCTSCLTSWQESEGQGCPFCRCEIKGTEPIVVDPF 77

RING finger, HC subclass, found in Casitas B-lineage lymphoma (Cbl) proteins; The Cbl adaptor protein family contains a small class of RING-type E3 ubiquitin ligases with oncogenic activity, which is represented by three mammalian members, c-Cbl, Cbl-b and Cbl-c, as well as two invertebrate Cbl-family proteins, D-Cbl in Drosophila and Sli-1 in C. elegans. Cbl proteins function as potent negative regulators of various signaling cascades in a wide range of cell types. They play roles in ubiquitinating activated tyrosine kinases and targeting them for degradation. D-Cbl associates with the Drosophila epidermal growth factor receptor (EGFR) and overexpression of D-Cbl in the eye of Drosophila embryos inhibits EGFR-dependent photoreceptor cell development. Sli-1 is a negative regulator of the Let-23 receptor tyrosine kinase, an EGFR homolog, in vulva development. Cbl proteins in this subfamily consist of a highly conserved N-terminal half that includes a tyrosine-kinase-binding domain (TKB, also known as the phosphotyrosine binding PTB domain, composed of a four helix-bundle, a Ca2+ binding EF-hand and a highly variant SH2 domain) and a C3HC4-type RING-HC finger, both of which are required for Cbl-mediated downregulation of RTKs, and a divergent C-terminal region.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|...
gi 2217346635 370 FQLCKICAENDKDVKIEPCGHLMCTSCLTAWQESDGQGCPFCR 412
Cdd:cd16502     1 FQLCKICAENDKDVRIEPCGHLLCTPCLTSWQDSDGQTCPFCR 43

RING finger (Really Interesting New Gene) domain and U-box domain superfamily; 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 different Cys/His patterns while some lack a single Cys or His residue at typical Zn ligand positions (the fourth or eighth zinc ligand is prevalently exchanged for an Asp, which can indeed chelate Zn in a RING finger as well). C4C4-, C3HC3D-, C2H2C4-, and C3HC5-type RING fingers are closely related to RING-HC fingers. In contrast, C4HC3- (RING-CH alias RINGv), C3H3C2-, C3H2C2D-, C3DHC3-, and C4HC2H-type RING fingers are more closely related to RING-H2 fingers. However, not all RING finger-containing proteins display regular RING finger features, and the RING finger family has turned out to be multifarious. The degenerate RING fingers of the Siz/PIAS RING (SP-RING) family proteins and sporulation protein RMD5, are characterized by lacking the second, fifth, and sixth Zn2+ ion-coordinating residues. They bind only one Zn2+ ion. On the other hand, the RING fingers of the human APC11 and RBX1 proteins can bind a third Zn atom since they harbor four additional Zn ligands. U-box is a modified form of the RING finger domain that lacks metal chelating Cys and His residues. It resembles the cross-brace RING structure consisting of three beta-sheets and a single alpha-helix, which would be stabilized by salt bridges instead of chelated metal ions. U-box proteins are widely distributed among eukaryotic organisms and show a higher prevalence in plants than in other organisms. RING finger/U-box-containing proteins are 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 enable efficient transfer of ubiquitin from E2 to the substrates.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|..
gi 2217346635 373 CKICAENDKD---VKIEPCGHLMCTSCLTAWQESDGQGCPFC 411
Cdd:cd00162     1 CPICREEMNDrrpVVLLSCGHTFSRSAIARWLEGSKQKCPFC 42

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
                  ....*....|....*....|....*....|....*....
gi 2217346635 373 CKICAENDKDVKIEPCGHLMCTSCLTAWQESDGQGCPFC 411
Cdd:cd16449     3 CPICLERLKDPVLLPCGHVFCRECIRRLLESGSIKCPIC 41

Zinc finger, C3HC4 type (RING finger);

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*....
gi 2217346635 371 QLCKICAENDKDVKIEPCGHL-MCTSCLTAWQESDGQgCPFCRCEIKGT 418
Cdd:pfam13920   3 LLCVICLDRPRNVVLLPCGHLcLCEECAERLLRKKKK-CPICRQPIESV 50

RING finger, HC subclass, found in RING finger protein 185 (RNF185) and similar proteins; RNF185 is an E3 ubiquitin-protein ligase of endoplasmic reticulum-associated degradation (ERAD) that targets cystic fibrosis transmembrane conductance regulator (CFTR). It controls the degradation of CFTR and CFTR F508del allele in a RING- and proteasome-dependent manner, but does not control that of other classical ERAD model substrates. It also negatively regulates osteogenic differentiation by targeting dishevelled2 (Dvl2), a key mediator of the Wnt signaling pathway, for degradation. Moreover, RNF185 regulates selective mitochondrial autophagy through interaction with the Bcl-2 family protein BNIP1. It also plays an important role in cell adhesion and migration through the modulation of cell migration by ubiquitinating paxillin. RNF185 contains a C3HC4-type RING-HC finger.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 2217346635 373 CKICAENDKDVKIEPCGHLMCTSCLTAWQES--DGQGCPFCRCEIKGTEPI 421
Cdd:cd16744     3 CNICLDTAKDAVVSLCGHLFCWPCLHQWLETrpNRQVCPVCKAGISRDKVI 53

RING finger, HC subclass, found in RING finger protein 5 (RNF5) and similar proteins; RNF5, also known as protein G16 or Ram1, is an E3 ubiquitin-protein ligase anchored to the outer membrane of the endoplasmic reticulum (ER). It acts at early stages of cystic fibrosis (CF) transmembrane conductance regulator (CFTR) biosynthesis and functions as a target for therapeutic modalities to antagonize mutant CFTR proteins in CF patients carrying the F508del allele. It also regulates the turnover of specific G protein-coupled receptors by ubiquitinating JNK-associated membrane protein (JAMP) and preventing proteasome recruitment. RNF5 limits basal levels of autophagy and influences susceptibility to bacterial infection through the regulation of ATG4B stability. It is also involved in the degradation of Pendrin, a transmembrane chloride/anion exchanger highly expressed in thyroid, kidney, and inner ear. RNF5 plays an important role in cell adhesion and migration. It can modulate cell migration by ubiquitinating paxillin. Furthermore, RNF5 interacts with virus-induced signaling adaptor (VISA) at mitochondria in a viral infection-dependent manner, and further targets VISA at K362 and K461 for K48-linked ubiquitination and degradation after viral infection. It also negatively regulates virus-triggered signaling by targeting MITA, also known as STING, for ubiquitination and degradation at the mitochondria. In addition, RNF5 determines breast cancer response to ER stress-inducing chemotherapies through the regulation of the L-glutamine carrier proteins SLC1A5 and SLC38A2 (SLC1A5/38A2). It also has been implicated in muscle organization and in recognition and processing of misfolded proteins. RNF5 contains a C3HC4-type RING-HC finger.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*
gi 2217346635 373 CKICAENDKDVKIEPCGHLMCTSCLTAWQES--DGQGCPFCRCEI 415
Cdd:cd16743     3 CNICLETARDAVVSLCGHLFCWPCLHQWLETrpERQECPVCKAGI 47

RING finger, HC subclass, found in RING finger protein RNF5, RNF185 and similar proteins; RNF5 and RNF185 are E3 ubiquitin-protein ligases that are anchored to the outer membrane of the endoplasmic reticulum (ER). RNF5 acts at early stages of cystic fibrosis (CF) transmembrane conductance regulator (CFTR) biosynthesis, and functions as a target for therapeutic modalities to antagonize mutant CFTR proteins in CF patients carrying the F508del allele. RNF185 controls the degradation of CFTR and CFTR F508del allele in a RING- and proteasome-dependent manner, but does not control that of other classical endoplasmic reticulum-associated degradation (ERAD) model substrates. Moreover, both RNF5 and RNF185 play important roles in cell adhesion and migration through the modulation of cell migration by ubiquitinating paxillin. Arabidopsis thaliana RING membrane-anchor proteins (AtRMAs) are also included in this family. They possess E3 ubiquitin-protein ligase activity and may play a role in the growth and development of Arabidopsis. All members of this family contain a C3HC4-type RING-HC finger.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|..
gi 2217346635 373 CKICAENDKDVKIEPCGHLMCTSCLTAWQE--SDGQGCPFCR 412
Cdd:cd16534     3 CNICLDTASDPVVTMCGHLFCWPCLYQWLEtrPDRQTCPVCK 44

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
                  ....*....|....*....|....*....|....*....|....*
gi 2217346635 373 CKICAENDKDVKIEPCGHL-MCTSCLTAWQESDGQgCPFCRCEIK 416
Cdd:cd16647     4 CVICYERPVDTVLYRCGHMcMCYDCALQLKRRGGS-CPICRAPIK 47

RING finger, HC subclass, found in checkpoint with forkhead and RING finger domains protein (CHFR); CHFR, also known as RING finger protein 196 (RNF196), is a checkpoint protein that delays entry into mitosis in response to stress. It functions as an E3 ubiquitin ligase that ubiquitinates and degrades its target proteins, such as Aurora-A, Plk1, Kif22, and PARP-1, which are critical for proper mitotic transitions. It also plays an important role in cell cycle progression and tumor suppression, and is negatively regulated by SUMOylation-mediated proteasomal ubiquitylation. Moreover, CHFR is involved in the early stage of the DNA damage response, which mediates the crosstalk between ubiquitination and poly-ADP-ribosylation. CHFR contains a fork head associated (FHA) domain and a C3HC4-type RING-HC finger.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*.
gi 2217346635 373 CKICAENDKD-VKIEPCGHLMCTSCLTAWQESDGQGCPFCRCEIKG 417
Cdd:cd16503     5 CSICQDLLHDcVSLQPCMHNFCAACYSDWMERSNTECPTCRATVQR 50

RING finger, H2 subclass, found in RING finger protein 103 (RNF103) and similar proteins; RNF103, also known as KF-1 or zinc finger protein 103 homolog (Zfp-103), is an endoplasmic reticulum (ER)-resident E3 ubiquitin-protein ligase that is widely expressed in many different organs, including brain, heart, kidney, spleen, and lung. It is involved in the ER-associated degradation (ERAD) pathway by interacting with components of the ERAD pathway, including Derlin-1 and VCP. RNF103 contains several hydrophobic regions at its N-terminal and middle regions, as well as a C-terminal C3H2C3-type RING-H2 finger.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*..
gi 2217346635 373 CKICAENDKD---VKIEPCGHLMCTSCLTAWQESDGQGCPFCRCEIK 416
Cdd:cd16473     7 CAICLENYQNgdlLRGLPCGHVFHQNCIDVWLERDNHCCPVCRWPVY 53

RING finger, H2 subclass, found in TRAF-interacting protein (TRAIP) and similar proteins; TRAIP, also known as RING finger protein 206 (RNF206) or TRIP, is a ubiquitously expressed nucleolar E3 ubiquitin ligase important for cellular proliferation and differentiation. It is found near mitotic chromosomes and functions as a regulator of the spindle assembly checkpoint. TRAIP interacts with tumor necrosis factor (TNF)-receptor-associated factor (TRAF) proteins and inhibits TNF-alpha-mediated nuclear factor (NF)-kappaB activation. It also interacts with two tumor suppressors CYLD and spleen tyrosine kinase (Syk), and DNA polymerase eta, which facilitates translesional synthesis after DNA damage. TRAIP contains an N-terminal C3H2C2-type RING-H2 finger and an extended coiled-coil domain.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....
gi 2217346635 372 LCKICAE---NDKDVKIEPCGHLMCTSCLTAWQESDgQGCPFCR 412
Cdd:cd16480     1 YCTICSDffdNSRDVAAIHCGHTFHYDCLLQWFDTS-RTCPQCR 43

RING finger, HC subclass, found in RING finger protein 141 (RNF141) and similar proteins; RNF141, also known as zinc finger protein 230 (ZNF230), is a RING finger protein present primarily in the nuclei of spermatogonia, the acrosome, and the tail of spermatozoa. It may have a broad function during early development of vertebrates. It plays an important role in spermatogenesis, including spermatogenic cell proliferation and sperm maturation, as well as motility and fertilization. It also exhibits DNA binding activity. RNF141/ZNF230 gene mutations may be associated with azoospermia. RNF141 contains a C3HC4-type RING finger domain that may function as an activator module in transcription.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|
gi 2217346635 373 CKICAENDKDVkIEPCGHLMCTSCLTAWQESDGQgCPFCR 412
Cdd:cd16545     3 CCICMDRKADL-ILPCAHSYCQKCIDKWSDRHRT-CPICR 40

Src homology 2 (SH2) domain; In general, SH2 domains are involved in signal transduction; they bind pTyr-containing polypeptide ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites. They are present in a wide array of proteins including: adaptor proteins (Nck1, Crk, Grb2), scaffolds (Slp76, Shc, Dapp1), kinases (Src, Syk, Fps, Tec), phosphatases (Shp-1, Shp-2), transcription factors (STAT1), Ras signaling molecules (Ras-Gap), ubiquitination factors (c-Cbl), cytoskeleton regulators (Tensin), signal regulators (SAP), and phospholipid second messengers (PLCgamma), amongst others.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 2217346635 258 PGYMAFLTYDEVKARLQkySTKPGSYIFRLSCTRLGQWAIGYVTGDGNILQTIPHNKPLFQALIDGSREGF 328
Cdd:cd00173     1 PWFHGSISREEAERLLR--GKPDGTFLVRESSSEPGDYVLSVRSGDGKVKHYLIERNEGGYYLLGGSGRTF 69

Modified RING finger, HC subclass (C3HC5-type), found in neuralized-like protein 1A (NEURL1A) and similar proteins; NEURL1A, also known as NEURL1, NEU, neuralized 1, or RING finger protein 67 (RNF67), is a mammalian homolog of the Drosophila neuralized (D-neu) protein. 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 the medulloblastoma. NEURL1A 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.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 2217346635 367 GSTFQLCKICAENDKDVKIEPCGHL-MCTSCLTAWQESDGQGCPFCRCEIK 416
Cdd:cd16785     1 GSWSDECTICYENAVDTVIYTCGHMcLCYACGLRLKKMLNACCPICRRAIK 51

RING finger, HC subclass, found in tripartite motif-containing protein 47 (TRIM47) and similar proteins; TRIM47, also known as gene overexpressed in astrocytoma protein (GOA) or RING finger protein 100 (RNF100), belongs to the C-IV subclass of the TRIM (tripartite motif) family of proteins that are defined by their N-terminal RBCC (RING, Bbox, and coiled coil) domains, including three consecutive zinc-binding domains, a C3HC4-type RING-HC finger, a B-box, and two coiled coil domains, as well as a B30.2/SPRY (SplA and ryanodine receptor) domain positioned C-terminal to the RBCC domain. It plays an important role in the process of dedifferentiation that is associated with astrocytoma tumorigenesis. This subfamily also includes RING finger protein 135 (RNF135). RNF135, also known as RIG-I E3 ubiquitin ligase (REUL) or Riplet, is a widely expressed E3 ubiquitin-protein ligase that consists of an N-terminal C3HC4-type RING-HC finger and C-terminal B30.2/SPRY and PRY motifs, but lacks the B-box and coiled-coil domains that are also typically present in TRIM proteins. RNF135 serves as a specific retinoic acid-inducible gene-I (RIG-I)-interacting protein that ubiquitinates RIG-I and specifically stimulates RIG-I-mediated innate antiviral activity to produce antiviral type-I interferon (IFN) during the early phase of viral infection. It also has been identified as a bio-marker and therapy target of glioblastoma. It associates with the ERK signal transduction pathway and plays a role in glioblastoma cell proliferation, migration and cell cycle.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|...
gi 2217346635 373 CKICAENDKDVKIEPCGHLMCTSCLTA-WQESDGQ--GCPFCR 412
Cdd:cd16604     3 CPICLDLLKDPVTLPCGHSFCMGCLGAlWGAGRGGraSCPLCR 45

RING finger, HC subclass, found in Saccharomyces cerevisiae POB3/SPT16 histone-associated protein 1 (ScPSH1) and similar proteins; ScPSH1 is a Cse4-specific E3 ubiquitin ligase that interacts with the kinetochore protein Pat1 and targets the degradation of budding yeast centromeric histone H3 variant, CENP-ACse4, which is essential for faithful chromosome segregation. ScPSH1 contains a C3HC4-type RING-HC finger and a DNA directed RNA polymerase domain.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*..
gi 2217346635 371 QLCKICAENDKDVKIEPCGHLMCTSCLTAWQES-DGQGCPFCRCEIK 416
Cdd:cd16568     5 QECIICHEYLYEPMVTTCGHTYCYTCLNTWFKSnRSLSCPDCRTKIT 51

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 2217346635 373 CKICAENDKDVKIEPCGHL-MCTSCltAWQE-SDGQGCPFCRCEIK 416
Cdd:cd16552     4 CAICFHHTANTRLVPCGHShFCGSC--AWHIfRDTARCPVCRWQIE 47

RING finger, HC subclass, found in RING finger protein 123 (RNF123) and similar proteins; RNF123, also known as Kip1 ubiquitination-promoting complex protein 1 (KPC1), is an E3 ubiquitin-protein ligase that mediates ubiquitination and proteasomal processing of the nuclear factor-kappaB 1 (NF-kappaB1) precursor p105 to the p50 active subunit that restricts tumor growth. It also regulates degradation of heterochromatin protein 1alpha (HP1alpha) and 1beta (HP1beta) in lamin A/C knock-down cells. Moreover, RNF123, together with Kip1 ubiquitylation-promoting complex 2 (KPC2), forms the Kip1 ubiquitination-promoting complex (KPC), acting as a cytoplasmic ubiquitin ligase that regulates degradation of the cyclin-dependent kinase inhibitor p27 (Kip1) at the G1 phase of the cell cycle. RNF123 may also function as a clinically relevant, peripheral state marker of depression. RNF123 contains a C3HC4-type RING-HC finger at the C-terminus.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*
gi 2217346635 371 QLCKICAENDKDVKIEPCGHLMCTSCLTAWQESDGQgCPFCRCEI 415
Cdd:cd16541     1 DLCPICYAHPIDAVFLPCGHKSCRSCINRHLMNNKE-CFFCKATI 44

RING finger, HC subclass, found in helicase-like transcription factor (HLTF) and similar proteins; HLTF, also known as DNA-binding protein/plasminogen activator inhibitor 1 regulator, HIP116, RING finger protein 80, SWI/SNF-related matrix-associated actin-dependent regulator of chromatin subfamily A member 3, or sucrose nonfermenting protein 2-like 3, is a yeast RAD5 homolog found in mammals. It has both E3 ubiquitin ligase and DNA helicase activities, and plays a pivotal role in the template-switching pathway of DNA damage tolerance. It is involved in Lys-63-linked poly-ubiquitination of proliferating cell nuclear antigen (PCNA) at Lys-164 and in the regulation of DNA damage tolerance. It shows double-stranded DNA translocase activity with 3'-5' polarity, thereby facilitating regression of the replication fork. HLTF contains an N-terminal HIRAN (HIP116 and RAD5 N-terminal) domain, a SWI/SNF helicase domain that is divided into N- and C-terminal parts by an insertion of a C3HC4-type RING-HC finger involved in the poly-ubiquitination of PCNA.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....
gi 2217346635 373 CKICAENDKDVKIEPCGHLMCTSCLTAWQESDGQGCPFCRCEIK 416
Cdd:cd16509     6 CAICLDSLTNPVITPCAHVFCRRCICEVIQREKAKCPMCRAPLS 49

RING finger, HC subclass, found in Dictyostelium discoideum Ras guanine nucleotide exchange factor O (RasGEFO) and similar proteins; RasGEFO, also known as RasGEF domain-containing protein O, functions as a Ras guanine-nucleotide exchange factor (RasGEFs), activating Ras by catalyzing the replacement of GDP with GTP. RasGEFs are particularly important for signaling in development and chemotaxis in many organisms, including Dictyostelium. RasGEFO contains a C3HC4-type RING-HC finger that may be responsible for E3 ubiquitin ligase activity.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*...
gi 2217346635 373 CKICAENDKDVK-IEPCGHLMCTSCLTAwqESDGQGCPFCRCEIKGTE 419
Cdd:cd16507    12 CGICQNLFKDPNtLIPCGHAFCLDCLTT--NASIKNCIQCKVEYTTYI 57

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 2217346635 372 LCKICAENDKDVKIEPCGHLM-CTSCLTAWQEsdgqgCPFCR 412
Cdd:cd16500     2 LCKICMDAAIDCVLLECGHMVtCTDCGKKLSE-----CPICR 38

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 2217346635 373 CKICAENDKDVKIEPCGHL-MCTSCLTAWQESDGQGCPFCRCEIK 416
Cdd:cd23128     6 CVMCMEEERSVVFLPCAHQvVCSGCNDLHEKKGMRECPSCRGEIQ 50

RING finger, H2 subclass, found in RING finger protein 165 (RNF165) and similar proteins; RNF165, also known as Arkadia-like 2, Arkadia2, or Ark2C, is an E3 ubiquitin ligase with homology to the C-terminal half of RNF111. It is expressed specifically in the nervous system, and can serve to amplify neuronal responses to specific signals. It acts as a positive regulator of bone morphogenetic protein (BMP)-Smad signaling that is involved in motor neuron (MN) axon elongation. RNF165 contains two serine rich domains, a nuclear localization signal, an NRG-TIER domain, and a C-terminal C3H2C3-type RING-H2 finger that is responsible for the enhancement of BMP-Smad1/5/8 signaling in the spinal cord.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 2217346635 365 EMGSTFQLCKICA---ENDKDVKIEPCGHLMCTSCLTAWQESDgQGCPFCRCEIK 416
Cdd:cd16682     2 EESDTDEKCTICLsmlEDGEDVRRLPCMHLFHQLCVDQWLAMS-KKCPICRVDIE 55

RING finger, HC subclass, found in tripartite motif-containing protein 69 (TRIM69) and similar proteins; TRIM69, also known as RFP-like domain-containing protein trimless or RING finger protein 36 (RNF36), is a testis E3 ubiquitin-protein ligase that plays a specific role in apoptosis and may also play an important role in germ cell homeostasis during spermatogenesis. TRIM69 belongs to the C-IV subclass of the TRIM (tripartite motif) family of proteins that are defined by their N-terminal RBCC (RING, Bbox, and coiled coil) domains, including three consecutive zinc-binding domains, a C3HC4-type RING-HC finger, Bbox1 and Bbox2, and a coiled coil region, as well as a B30.2/SPRY (SplA and ryanodine receptor) domain positioned C-terminal to the RBCC domain.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*..
gi 2217346635 373 CKICAENDKDVKIEPCGHLMCTSCLTAWQESDGQG--CPFCRCEIKG 417
Cdd:cd16611     7 CPLCLDFFRDPVMLSCGHNFCQSCITGFWELQAEDttCPECRELCQY 53

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        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 2217346635 373 CKICAENDKDVKIEPCGHL-MCTSCLTAWQESdgQGCPFCRCEIKGTEPI 421
Cdd:cd16648     4 CVICLSNPRSCVFLECGHVcSCIECYEALPSP--KKCPICRSFIKRVVPL 51

RING finger, HC subclass, found in tripartite motif-containing protein 40 (TRIM40) and similar proteins; TRIM40, also known as probable E3 NEDD8-protein ligase or RING finger protein 35 (RNF35), is highly expressed in the gastrointestinal tract including the stomach, small intestine, and large intestine. It enhances neddylation of inhibitor of nuclear factor kappaB kinase subunit gamma (IKKgamma), inhibits the activity of nuclear factor-kappaB (NF-kappaB)-mediated transcription, and thus prevents inflammation-associated carcinogenesis in the gastrointestinal tract. TRIM40 belongs to the C-V subclass of the TRIM (tripartite motif) family of proteins that are defined by an N-terminal RBCC (RING, Bbox, and coiled coil) domain, including three consecutive zinc-binding domains, a C3HC4-type RING-HC finger, Bbox1 and Bbox2, and a coiled coil region, as well as an uncharacterized region positioned C-terminal to the RBCC domain.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*
gi 2217346635 372 LCKICAENDKDVKIEPCGHLMCTSCLTAWQE----SDGQGCPFCR 412
Cdd:cd16583     7 VCPICQEPLKEAVSTDCGHLFCRMCLTQHAKkasaSGVFSCPVCR 51

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.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*
gi 2217346635 373 CKICAENDKDVKIEPCGHL-MCTSCltAWQ-ESdgqgCPFCRCEI 415
Cdd:cd16566     5 CTLCFDKVADTELRPCGHSgFCMEC--ALQlET----CPLCRQPI 43

RING finger, H2 subclass, found in RING finger protein 111 (RNF111) and similar proteins; RNF111, also known as Arkadia, is a nuclear E3 ubiquitin-protein ligase that targets intracellular effectors and modulators of transforming growth factor beta (TGF-beta)/Nodal-related signaling for polyubiquitination and proteasome-dependent degradation. It acts as an amplifier of Nodal signals, and enhances the dorsalizing activity of limiting amounts of Xnr1, a Nodal homolog, and requires Nodal signaling for its function. The loss of RNF111 results in early embryonic lethality, with defects attributed to compromised Nodal signaling. RNF111 also regulates tumor metastasis by modulation of the TGF-beta pathway. Its ubiquitination can be modulated by the four and a half LIM-only protein 2 (FHL2) that activates TGF-beta signal transduction. Furthermore, RNF111 interacts with the clathrin-adaptor 2 (AP2) complex and regulates endocytosis of certain cell surface receptors, leading to modulation of epidermal growth factor (EGF) and possibly other signaling pathways. In addition, RNF111 has been identified as a small ubiquitin-like modifier (SUMO)-binding protein with clustered SUMO-interacting motifs (SIMs) that together form a SUMO-binding domain (SBD). It thus functions as a SUMO-targeted ubiquitin ligase (STUbL) that directly links nonproteolytic ubiquitylation and SUMOylation in the DNA damage response, as well as triggers degradation of signal-induced polysumoylated proteins, such as the promyelocytic leukemia protein (PML). The N-terminal half of RNF111 harbors three SIMs. Its C-terminal half show high sequence similarity with RING finger protein 165 (RNF165), where it contains two serine rich domains, two nuclear localization signals, an NRG-TIER domain, and a C-terminal C3H2C3-type RING-H2 finger that is required for polyubiqutination and proteasome-dependent degradation of phosphorylated forms of Smad2/3 and three major negative regulators of TGF-beta signaling, Smad7, SnoN and c-Ski.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 2217346635 369 TFQLCKICA---ENDKDVKIEPCGHLMCTSCLTAWQESDgQGCPFCRCEIK 416
Cdd:cd16681     9 TEEKCTICLsilEEGEDVRRLPCMHLFHQVCVDQWLITN-KKCPICRVDIE 58

RING finger, HC subclass, found in RING finger protein 219 (RNF219) and similar proteins; RNF219 may function as a modulator of late-onset Alzheimer's disease (LOAD) associated amyloid beta A4 precursor protein (APP) endocytosis and metabolism. It genetically interacts with apolipoprotein E epsilon4 allele (APOE4). Thus, a genetic variant of RNF219 was found to affect amyloid deposition in human brain and LOAD age-of-onset. Moreover, common genetic variants at the RNF219 locus had been associated with alternations in lipid metabolism, cognitive performance and central nervous system ventricle volume. RNF219 contains a C3HC4-type RING-HC finger.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|...
gi 2217346635 373 CKICAENDKDVKIEPCGHLMCTSCLTAWQESDGQgCPFCRCEI 415
Cdd:cd16562     4 CHICLGKVRQPVICSNNHVFCSSCMDVWLKNNNQ-CPACRVPI 45

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.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*
gi 2217346635 371 QLCKICAENDKDVkIEPCGHLMCTSCLTAWQEsdgqgCPFCRCEI 415
Cdd:cd16520     1 ILCPICMERKKNV-VFLCGHGTCQKCAEKLKK-----CPICRKPI 39

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.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*
gi 2217346635 373 CKICAENDKDVKIEPCGHL-MCTSCLTAWQESDGQGCPFCRCEIK 416
Cdd:cd16786     5 CTVCFDSEVDTVIYTCGHMcLCNSCGLKLKRQINACCPICRRVIK 49