U-box domain, a modified RING finger, found in RING finger protein 37 (RNF37); RNF37, also known as KIAA0860, U-box domain-containing protein 5 (UBOX5), UbcM4-interacting protein 5 (UIP5), or ubiquitin-conjugating enzyme 7-interacting protein 5, is an E3 ubiquitin-protein ligase found exclusively in the nucleus as part of a nuclear dot-like structure. It interacts with the molecular chaperone VCP/p97 protein. RNF37 contains a U-box domain followed by a potential nuclear location signal (NLS), and a C-terminal C3HC4-type RING-HC finger. The U-box domain is a modified RING finger domain that lacks the hallmark metal-chelating cysteines and histidines of the latter, but is likely to adopt a RING finger-like conformation. The presence of the U-box, but not of the RING finger, is required for the E3 activity. The U-box domain can directly interact with several E2 enzymes, including UbcM2, UbcM3, UbcM4, UbcH5, and UbcH8, suggesting a similar function as the RING finger in the ubiquitination pathway. This model corresponds to the U-box domain.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|...
gi 7662344  260 PEEFLDPITLEIMPCPMLLPSGKVIDQSTLEKCNRSEATWGRVPSDPFTGVAF 312
Cdd:cd16660   1 PEEFLDPITCELMTLPVLLPSGKVVDQSTLEKYIKEEATWGRLPSDPFTGVPF 53

U-box domain, a modified RING finger, found in RING finger protein 37 (RNF37); RNF37, also known as KIAA0860, U-box domain-containing protein 5 (UBOX5), UbcM4-interacting protein 5 (UIP5), or ubiquitin-conjugating enzyme 7-interacting protein 5, is an E3 ubiquitin-protein ligase found exclusively in the nucleus as part of a nuclear dot-like structure. It interacts with the molecular chaperone VCP/p97 protein. RNF37 contains a U-box domain followed by a potential nuclear location signal (NLS), and a C-terminal C3HC4-type RING-HC finger. The U-box domain is a modified RING finger domain that lacks the hallmark metal-chelating cysteines and histidines of the latter, but is likely to adopt a RING finger-like conformation. The presence of the U-box, but not of the RING finger, is required for the E3 activity. The U-box domain can directly interact with several E2 enzymes, including UbcM2, UbcM3, UbcM4, UbcH5, and UbcH8, suggesting a similar function as the RING finger in the ubiquitination pathway. This model corresponds to the U-box domain.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|...
gi 7662344  260 PEEFLDPITLEIMPCPMLLPSGKVIDQSTLEKCNRSEATWGRVPSDPFTGVAF 312
Cdd:cd16660   1 PEEFLDPITCELMTLPVLLPSGKVVDQSTLEKYIKEEATWGRLPSDPFTGVPF 53

RING finger, HC subclass, found in RING finger protein 37 (RNF37); RNF37, also known as KIAA0860, U-box domain-containing protein 5 (UBOX5), UbcM4-interacting protein 5 (UIP5), or ubiquitin-conjugating enzyme 7-interacting protein 5, is an E3 ubiquitin-protein ligase found exclusively in the nucleus as part of a nuclear dot-like structure. It interacts with the molecular chaperone VCP/p97 protein. RNF37 contains a U-box domain followed by a potential nuclear location signal (NLS) and a C-terminal C3HC4-type RING-HC finger. The U-box domain is a modified RING finger domain that lacks the hallmark metal-chelating cysteines and histidines of the latter, and is likely to adopt a RING finger-like conformation. The presence of the U-box, but not of the RING finger, is required for the E3 activity. The U-box domain can directly interact with several E2 enzymes, including UbcM2, UbcM3, UbcM4, UbcH5, and UbcH8, suggesting a similar function as the RING finger in the ubiquitination pathway. This model corresponds to the RING-HC finger.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|..
gi 7662344  481 PECASCKRVFSPYFKKEPVYQLPCGHLLCRPCLGEKQRSLPMTCTACQRPVA 532
Cdd:cd16537   1 QGCASCSRAFSPYFKTEPVYRLPCGHLLCRPCLAEKQKSLAILCPTCNRPVA 52

zinc-RING finger domain;

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....
gi 7662344    486 CKRVFSPYFKKEPVYQLPCGHLLCRPCLGEKQRslPMTCTACQR 529
Cdd:pfam14634   2 CNKCFKELSKTRPFYLTSCGHIFCEECLTRLLQ--ERQCPICKK 43

U-box domain, a modified RING finger, found in RING finger protein 37 (RNF37); RNF37, also known as KIAA0860, U-box domain-containing protein 5 (UBOX5), UbcM4-interacting protein 5 (UIP5), or ubiquitin-conjugating enzyme 7-interacting protein 5, is an E3 ubiquitin-protein ligase found exclusively in the nucleus as part of a nuclear dot-like structure. It interacts with the molecular chaperone VCP/p97 protein. RNF37 contains a U-box domain followed by a potential nuclear location signal (NLS), and a C-terminal C3HC4-type RING-HC finger. The U-box domain is a modified RING finger domain that lacks the hallmark metal-chelating cysteines and histidines of the latter, but is likely to adopt a RING finger-like conformation. The presence of the U-box, but not of the RING finger, is required for the E3 activity. The U-box domain can directly interact with several E2 enzymes, including UbcM2, UbcM3, UbcM4, UbcH5, and UbcH8, suggesting a similar function as the RING finger in the ubiquitination pathway. This model corresponds to the U-box domain.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|...
gi 7662344  260 PEEFLDPITLEIMPCPMLLPSGKVIDQSTLEKCNRSEATWGRVPSDPFTGVAF 312
Cdd:cd16660   1 PEEFLDPITCELMTLPVLLPSGKVVDQSTLEKYIKEEATWGRLPSDPFTGVPF 53

RING finger, HC subclass, found in RING finger protein 37 (RNF37); RNF37, also known as KIAA0860, U-box domain-containing protein 5 (UBOX5), UbcM4-interacting protein 5 (UIP5), or ubiquitin-conjugating enzyme 7-interacting protein 5, is an E3 ubiquitin-protein ligase found exclusively in the nucleus as part of a nuclear dot-like structure. It interacts with the molecular chaperone VCP/p97 protein. RNF37 contains a U-box domain followed by a potential nuclear location signal (NLS) and a C-terminal C3HC4-type RING-HC finger. The U-box domain is a modified RING finger domain that lacks the hallmark metal-chelating cysteines and histidines of the latter, and is likely to adopt a RING finger-like conformation. The presence of the U-box, but not of the RING finger, is required for the E3 activity. The U-box domain can directly interact with several E2 enzymes, including UbcM2, UbcM3, UbcM4, UbcH5, and UbcH8, suggesting a similar function as the RING finger in the ubiquitination pathway. This model corresponds to the RING-HC finger.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|..
gi 7662344  481 PECASCKRVFSPYFKKEPVYQLPCGHLLCRPCLGEKQRSLPMTCTACQRPVA 532
Cdd:cd16537   1 QGCASCSRAFSPYFKTEPVYRLPCGHLLCRPCLAEKQKSLAILCPTCNRPVA 52

U-box domain, a modified RING finger, found in ubiquitin conjugation factor E4 B (UBE4B) and similar proteins; UBE4B, also known as UFD2a, is a U-box-type ubiquitin-protein ligase that functions as an E3 ubiquitin ligase and an E4 polyubiquitin chain elongation factor, which catalyzes formation of Lys27- and Lys33-linked polyubiquitin chains rather than the Lys48-linked chain. It is a mammalian homolog of yeast UFD2 ubiquitination factor and it participates in the proteasomal degradation of misfolded or damaged proteins through association with chaperones. It is located in common neuroblastoma deletion regions and may be subject to mutations in tumors. UBE4B has contradictory functions upon tumorigenesis as an oncogene or tumor suppressor in different types of cancers. It is essential for Hdm2 (also known as Mdm2)-mediated p53 degradation. It mediates p53 polyubiquitination and degradation, as well as inhibits p53-dependent transactivation and apoptosis, and thus plays an important role in regulating phosphorylated p53 following DNA damage. UBE4B is also associated with other pathways independent of the p53 family, such as polyglutamine aggregation and Wallerian degeneration, both of which are critical in neurodegenerative diseases. Moreover, UBE4B acts as a regulator of epidermal growth factor receptor (EGFR) degradation. It is recruited to endosomes in response to EGFR activation by binding to Hrs, a key component of endosomal sorting complex required for transport (ESCRT) 0, and then regulates endosomal sorting, affecting cellular levels of the EGFR and its downstream signaling. UBE4B contains a ubiquitin elongating factor core and a RING-like U-box domain at the C-terminus.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 7662344  258 DVPEEFLDPITLEIMPCPMLLPSGKVIDQSTLEKCNRSEatwgrvPSDPFTgvaftphSQPL------PHPSLKARIDHF 331
Cdd:cd16658   3 DAPDEFLDPLMDTLMTDPVILPSGTIMDRSIILRHLLNS------QTDPFN-------RQPLtedmlePVPELKERIQAW 69

                .
gi 7662344  332 L 332
Cdd:cd16658  70 I 70

U-box domain, a modified RING finger, found in ubiquitin conjugation factor E4 A (UBE4A) and similar proteins; This subfamily includes yeast ubiquitin fusion degradation protein 2 (UFD2p) and its mammalian homolog, UBE4A. Yeast UFD2p, also known as ubiquitin conjugation factor E4 or UB fusion protein 2, is a polyubiquitin chain conjugation factor (E4) in the ubiquitin fusion degradation (UFD) pathway which catalyzes elongation of the ubiquitin chain through Lys48 linkage. It binds to substrates conjugated with one to three ubiquitin molecules and catalyzes the addition of further ubiquitin moieties in the presence of ubiquitin-activating enzyme (E1), ubiquitin-conjugating enzyme (E2) and ubiquitin ligase (E3), yielding multiubiquitylated substrates that are targets for the 26S proteasome. UFD2p is implicated in cell survival under stress conditions and is essential for homoeostasis of unsaturated fatty acids. It interacts with UBL-UBA proteins Rad23 and Dsk2, which are involved in the endoplasmic reticulum-associated degradation, ubiquitin fusion degradation, and OLE-1 gene induction pathways. UBE4A is a U-box-type ubiquitin-protein ligase that is located in common neuroblastoma deletion regions and may be subject to mutations in tumors. It may have a specific role in different biochemical processes other than ubiquitination, including growth or differentiation. Members of this family contain an N-terminal ubiquitin elongating factor core and a RING-like U-box domain at the C-terminus.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 7662344  261 EEFLDPITLEIMPCPMLLPSGKV-IDQSTLEKCNRSEATwgrvpsDPFTGVAFTPhSQPLPHPSLKARIDHFLLQH 335
Cdd:cd16657   1 DEFLDPIMYTLMKDPVILPSSKVtVDRSTIKRHLLSDQT------DPFNRSPLTL-DMVIPNEELKQKIEEFLAEK 69

U-box domain, a modified RING finger, found in carboxyl terminus of HSP70-interacting protein (CHIP) and similar proteins; CHIP, also known as STIP1 homology and U box-containing protein 1 (STUB1), CLL-associated antigen KW-8, or Antigen NY-CO-7, is a multifunctional protein that functions both as a co-chaperone and an E3 ubiquitin-protein ligase. It couples protein folding and proteasome mediated degradation by interacting with heat shock proteins (e.g. HSC70) and ubiquitinating their misfolded client proteins, thereby targeting them for proteasomal degradation. It is also important for cellular differentiation and survival (or apoptosis), as well as susceptibility to stress. It targets a wide range of proteins, such as expanded ataxin-1, ataxin-3, huntingtin, and androgen receptor, which play roles in glucocorticoid response, tau degradation, and both p53 and cAMP signaling. CHIP contains an N-terminal tetratricopeptide repeat (TPR) domain responsible for protein-protein interaction, a highly charged middle coiled-coil (CC), and a C-terminal RING-like U-box domain acting as an ubiquitin ligase.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 7662344  259 VPEEFLDPITLEIMPCPMLLPSGKVIDQSTLEKCNRSEATWgrvpsDPFTGVAFTPhSQPLPHPSLKARIDHFLLQH 335
Cdd:cd16654   1 VPDYLCCKISFELMRDPVITPSGITYERKDIEEHLQRVGHF-----DPITREPLTQ-DQLIPNLALKEAIEAFLEEN 71

first U-box domain, a modified RING finger, found in Legionella pneumophila U-box protein LubX and similar proteins; LubX, also called RING-type E3 ubiquitin transferase LubX, is part of the large arsenal of effectors in Legionella pneumophila that are translocated into the host cytosol during infection. LubX acts as an E3 ubiquitin-protein ligase (EC 2.3.2.27) that interferes with the host's ubiquitination pathway. LubX contains two RING-like U-box domains. U-box 1 is critical to the ubiquitin ligase activity, and U-box 2 mediates interaction with host target. This model corresponds to the first one.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|.
gi 7662344  263 FLDPITLEIMPCPMLLPSGKVIDQSTLEKCNRSEatwgrvPSDPFTGVAFT 313
Cdd:cd23149   1 FTCPITSGFMEDPVITPSGFSYERSAIERWLETK------PEDPQTREPLT 45

RING finger, HC subclass, found in RING finger protein 138 (RNF138) and similar proteins; RNF138, also known as Nemo-like kinase-associated RING finger protein (NARF) or NLK-associated RING finger protein, is an E3 ubiquitin-protein ligase that plays an important role in glioma cell proliferation, apoptosis, and cell cycle. It specifically cooperates with the E2 conjugating enzyme E2-25K (Hip-2/UbcH1), regulates the ubiquitylation and degradation of T cell factor/lymphoid enhancer factor (TCF/LEF), and further suppresses Wnt-beta-catenin signaling. RNF138, together with three closely related proteins: RNF114, RNF125 and RNF166, forms a novel family of ubiquitin ligases with a C3HC4-type RING-HC finger, a C2HC-, and two C2H2-type zinc fingers, as well as a ubiquitin interacting motif (UIM).

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|..
gi 7662344  482 ECASCKRVFspyfkKEPVYQLPCGHLLCRPCLGEKQRSLPMTCTACQRPVAS 533
Cdd:cd16544   4 TCPVCQEVL-----KDPVELPPCRHIFCKACILLALRSSGARCPLCRGPVGK 50

Zinc finger, C3HC4 type (RING finger); The C3HC4 type zinc-finger (RING finger) is a cysteine-rich domain of 40 to 60 residues that coordinates two zinc ions, and has the consensus sequence: C-X2-C-X(9-39)-C-X(1-3)-H-X(2-3)-C-X2-C-X(4-48)-C-X2-C where X is any amino acid. Many proteins containing a RING finger play a key role in the ubiquitination pathway.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*
gi 7662344    483 CASCKRVFspyfkKEPVYQLPCGHLLCRPCLGEKQRSLPMTCTAC 527
Cdd:pfam00097   1 CPICLEEP-----KDPVTLLPCGHLFCSKCIRSWLESGNVTCPLC 40

RING finger, HC subclass, found in RING finger protein 125 (RNF125); RNF125, also known as T-cell RING activation protein 1 (TRAC-1), is an E3 ubiquitin-protein ligase that is predominantly expressed in lymphoid cells, and functions as a positive regulator of T cell activation. It also down-modulates HIV replication and inhibits pathogen-induced cytokine production. It negatively regulates type I interferon signaling, which conjugates Lys(48)-linked ubiquitination to retinoic acid-inducible gene-I (RIG-I) and subsequently leads to the proteasome-dependent degradation of RIG-I. Further, RNF125 conjugates ubiquitin to melanoma differentiation-associated gene 5 (MDA5), a family protein of RIG-I. It thus acts as a negative regulator of RIG-I signaling, and is a direct target of miR-15b in the context of Japanese encephalitis virus (JEV) infection. Moreover, RNF125 binds to and ubiquitinates JAK1, prompting its degradation and inhibition of receptor tyrosine kinase (RTK) expression. It also negatively regulates p53 function through physical interaction and ubiquitin-mediated proteasome degradation. Mutations in RNF125 may lead to overgrowth syndromes (OGS). RNF125, together with three closely related proteins: RNF114, RNF138 and RNF166, forms a novel family of ubiquitin ligases with a C3HC4-type RING-HC finger, a C2HC-, and two C2H2-type zinc fingers, as well as a ubiquitin interacting motif (UIM). The UIM of RNF125 binds K48-linked poly-ubiquitin chains and is, together with the RING domain, required for auto-ubiquitination.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|...
gi 7662344  482 ECASCKRVFspyfkKEPVyQLPCGHLLCRPCLGEKQRSLPMTCTACQRPVASQ 534
Cdd:cd16542   3 DCAVCLEVL-----HQPV-RTRCGHVFCRPCIATSLRNNTWTCPYCRAYLSSE 49