APC10-like DOC1 domains in E3 ubiquitin ligases that mediate substrate ubiquitination; This family contains the single domain protein, APC10, a subunit of the anaphase-promoting complex (APC), as well as the DOC1 domain of multi-domain proteins present in E3 ubiquitin ligases. E3 ubiquitin ligases mediate substrate ubiquitination (or ubiquitylation), a component of the ubiquitin-26S proteasome pathway for selective proteolytic degradation. The APC, a multi-protein complex (or cyclosome), is a cell cycle-regulated, E3 ubiquitin ligase that controls important transitions in mitosis and the G1 phase by ubiquitinating regulatory proteins, thereby targeting them for degradation. APC10-like DOC1 domains such as those present in HECT (Homologous to the E6-AP Carboxyl Terminus) and Cullin-RING (Really Interesting New Gene) E3 ubiquitin ligase proteins, HECTD3, and CUL7, respectively, are also included in this hierarchy. CUL7 is a member of the Cullin-RING ligase family and functions as a molecular scaffold assembling a SCF-ROC1-like E3 ubiquitin ligase complex consisting of Skp1, CUL7, Fbx29 F-box protein, and ROC1 (RING-box protein 1) and promotes ubiquitination. CUL7 is a multi-domain protein with a C-terminal cullin domain that binds ROC1 and a centrally positioned APC10/DOC1 domain. HECTD3 contains a C-terminal HECT domain which contains the active site for ubiquitin transfer onto substrates, and an N-terminal APC10 domain which is responsible for substrate recognition and binding. An APC10/DOC1 domain homolog is also present in HERC2 (HECT domain and RLD2), a large multi-domain protein with three RCC1-like domains (RLDs), additional internal domains including zinc finger ZZ-type and Cyt-b5 (Cytochrome b5-like Heme/Steroid binding) domains, and a C-terminal HECT domain. Recent studies have shown that the protein complex HERC2-RNF8 coordinates ubiquitin-dependent assembly of DNA repair factors on damaged chromosomes. Also included in this hierarchy is an uncharacterized APC10/DOC1-like domain found in a multi-domain protein, which also contains CUB, zinc finger ZZ-type, and EF-hand domains. The APC10/DOC1 domain forms a beta-sandwich structure that is related in architecture to the galactose-binding domain-like fold; their sequences are quite dissimilar, however, and are not included here.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 767939565 1057 DKCWEKVEVSSNPHRASKLTDHNPKTYWESNGSTGSHYITLHMHRGVLVRQLTLLVASEDSSYMPARVVVFGGDSTSCIG 1136
Cdd:cd08665     1 DKCWEKVEVSSNPHRANKLTDGNPKTYWESNGSTGSHYINIHMHRGVVIRQLYMLVASEDSSYMPARVVVLGGDSPSCIT 80

                          90       100       110       120       130
                  ....*....|....*....|....*....|....*....|....*....|.
gi 767939565 1137 TELNTVNVMPSASRVILLENLNRFWPIIQIRIKRCQQGGIDTRVRGVEVLG 1187
Cdd:cd08665    81 TELNAVNVSPTASRVVLLENMTRFWPIIQIRIKRCQQGGIDTRVRGLEILG 131

Rcat domain found in cullin-9 (CUL-9) and similar proteins; CUL-9, also called UbcH7-associated protein 1 (H7-AP1), p53-associated parkin-like cytoplasmic protein, or PARC, is a cytoplasmic RBR-type E3 ubiquitin-protein ligase that function as a tumor suppressor and promotes p53-dependent apoptosis. It mediates the ubiquitination and degradation of cytosolic cytochrome c to promote survival in neurons and cancer cells. It is also a critical downstream effector of the 3M complex in the maintenance of microtubules and genome integrity. Moreover, CUL-9, together with CUL-7, forms homodimers and heterodimers, as well as some atypical cullin RING ligase complexes, which may exhibit ubiquitin ligase activity. CUL-9 contains a CPH domain (conserved in Cul7, PARC, and HERC2 proteins), a DOC (DOC1/APC10) domain, cullin homology domains linked with E3 ligase function, and a C-terminal RBR domain previously known as RING-BetweenRING-RING domain or TRIAD [two RING fingers and a DRIL (double RING finger linked)] domain. Based on current understanding of the structural biology of RBR ligases, the nomenclature of RBR has been changed to RING1-BRcat (benign-catalytic)-Rcat (required-for-catalysis) recently. The RBR domain uses an auto-inhibitory mechanism to modulate ubiquitination activity, as well as a hybrid mechanism that combines aspects from both RING and HECT E3 ligase functions to facilitate the ubiquitination reaction. This model corresponds to the Rcat domain of CUL-9 that is essential for RBR E3 ligase activity and adopts the same fold as the BRcat domain.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*...
gi 767939565 2166 HLAKLISKRCPSCQAPIEKNEGCLHMTCAKCNHGFCWRCLKSWKPNHKDYYNCSAMVS 2223
Cdd:cd20359     1 HLAKLISKRCPSCQAQIEKNEGCLHMTCAKCNHGFCWRCLKPWKPTHKDYYNCSAMVS 58

Mouse development and cellular proliferation protein Cullin-7; The Cullin Ring Ligase family member, Cul7, is required for normal mouse development and cellular proliferation. Cul7 has a CPH domain which is a p53 interaction domain. The CPH domain interaction surface of P53 is present in the tetramerization domain.

                           10        20        30        40        50
                   ....*....|....*....|....*....|....*....|....*....|....*
gi 767939565   366 RSEFSSRSGYGEYVQQTLQPGMRVRMLDDYEEISAGDEGEFRQSNNGI---PPVQ 417
Cdd:pfam11515    1 RSDFASRDDYAEYVRDNLAPGMRVRCCRDYEEVSAGDEGEVIQSNRGGlhdLNVQ 55

Cullin protein neddylation domain; This is the neddylation site of cullin proteins which are a family of structurally related proteins containing an evolutionarily conserved cullin domain. With the exception of APC2, each member of the cullin family is modified by Nedd8 and several cullins function in Ubiquitin-dependent proteolysis, a process in which the 26S proteasome recognises and subsequently degrades a target protein tagged with K48-linked poly-ubiquitin chains. Cullins are molecular scaffolds responsible for assembling the ROC1/Rbx1 RING-based E3 ubiquitin ligases, of which several play a direct role in tumorigenesis. Nedd8/Rub1 is a small ubiquitin-like protein, which was originally found to be conjugated to Cdc53, a cullin component of the SCF (Skp1-Cdc53/CUL1-F-box protein) E3 Ub ligase complex in Saccharomyces cerevisiae, and Nedd8 modification has now emerged as a regulatory pathway of fundamental importance for cell cycle control and for embryogenesis in metazoans. The only identified Nedd8 substrates are cullins. Neddylation results in covalent conjugation of a Nedd8 moiety onto a conserved cullin lysine residue.

                            10        20        30        40        50        60        70        80
                    ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 767939565   1803 TLEQKRNLLSCLLVRILKAHGEkgLHIDQLVCLVLEAWQKGPNPpgtlghTVAggvactstDVLSCILHLLGQGYVKRRD 1882
Cdd:smart00884    1 VEEDRKLEIQAAIVRIMKSRKT--LSHSELVSEVIEQLKKRFKP------SVS--------DIKKRIESLIEREYLERDE 64

                    .
gi 767939565   1883 D 1883
Cdd:smart00884   65 D 65

APC10-like DOC1 domain of CUL7, subunit of the SCF-ROC1-like E3 ubiquitin ligase complex that mediates substrate ubiquitination; This model represents the APC10/DOC1 domain present in CUL7, a subunit of the SCF-ROC1-like E3 Ubiquitin (Ub) ligase complex, which mediates substrate ubiquitination (or ubiquitylation), and is a component of the ubiquitin-26S proteasome pathway for selective proteolytic degradation. CUL7 is a member of the Cullin-RING ligase family and functions as a molecular scaffold assembling the SCF-ROC1-like E3 Ub ligase complex consisting of the adapter protein Skp1, CUL7, the WD40 repeat-containing F-box Fbw8 (also known as Fbx29), and ROC1 (RING-box protein 1). CUL7 is a large protein with a C-terminal cullin domain that binds ROC1 and additional domains, including an APC10/DOC1 domain. While the Fbw8 protein is responsible for substrate protein recognition, the ROC1 RING domain recruits an Ub-charged E2 Ub-conjugating enzyme for substrate ubiquitination. It remains to be determined how CUL7 binds to the Skp1-Fbw8 heterodimer. The CUL7 E3 Ub ligase has been implicated in the proteasomal degradation of the cellular proteins, cyclin D1, an important regulator of the G1 to S-phase cell cycle progression, and insulin receptor substrate 1, a critical component of the signaling pathways downstream of the insulin and insulin-like growth factor 1 receptor. CUL7 appears to be an important regulator of placental development. Germ line mutations of CUL7 are linked to 3-M syndrome and Yakuts short stature syndrome.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 767939565 1057 DKCWEKVEVSSNPHRASKLTDHNPKTYWESNGSTGSHYITLHMHRGVLVRQLTLLVASEDSSYMPARVVVFGGDSTSCIG 1136
Cdd:cd08665     1 DKCWEKVEVSSNPHRANKLTDGNPKTYWESNGSTGSHYINIHMHRGVVIRQLYMLVASEDSSYMPARVVVLGGDSPSCIT 80

                          90       100       110       120       130
                  ....*....|....*....|....*....|....*....|....*....|.
gi 767939565 1137 TELNTVNVMPSASRVILLENLNRFWPIIQIRIKRCQQGGIDTRVRGVEVLG 1187
Cdd:cd08665    81 TELNAVNVSPTASRVVLLENMTRFWPIIQIRIKRCQQGGIDTRVRGLEILG 131

Rcat domain found in cullin-9 (CUL-9) and similar proteins; CUL-9, also called UbcH7-associated protein 1 (H7-AP1), p53-associated parkin-like cytoplasmic protein, or PARC, is a cytoplasmic RBR-type E3 ubiquitin-protein ligase that function as a tumor suppressor and promotes p53-dependent apoptosis. It mediates the ubiquitination and degradation of cytosolic cytochrome c to promote survival in neurons and cancer cells. It is also a critical downstream effector of the 3M complex in the maintenance of microtubules and genome integrity. Moreover, CUL-9, together with CUL-7, forms homodimers and heterodimers, as well as some atypical cullin RING ligase complexes, which may exhibit ubiquitin ligase activity. CUL-9 contains a CPH domain (conserved in Cul7, PARC, and HERC2 proteins), a DOC (DOC1/APC10) domain, cullin homology domains linked with E3 ligase function, and a C-terminal RBR domain previously known as RING-BetweenRING-RING domain or TRIAD [two RING fingers and a DRIL (double RING finger linked)] domain. Based on current understanding of the structural biology of RBR ligases, the nomenclature of RBR has been changed to RING1-BRcat (benign-catalytic)-Rcat (required-for-catalysis) recently. The RBR domain uses an auto-inhibitory mechanism to modulate ubiquitination activity, as well as a hybrid mechanism that combines aspects from both RING and HECT E3 ligase functions to facilitate the ubiquitination reaction. This model corresponds to the Rcat domain of CUL-9 that is essential for RBR E3 ligase activity and adopts the same fold as the BRcat domain.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*...
gi 767939565 2166 HLAKLISKRCPSCQAPIEKNEGCLHMTCAKCNHGFCWRCLKSWKPNHKDYYNCSAMVS 2223
Cdd:cd20359     1 HLAKLISKRCPSCQAQIEKNEGCLHMTCAKCNHGFCWRCLKPWKPTHKDYYNCSAMVS 58

Mouse development and cellular proliferation protein Cullin-7; The Cullin Ring Ligase family member, Cul7, is required for normal mouse development and cellular proliferation. Cul7 has a CPH domain which is a p53 interaction domain. The CPH domain interaction surface of P53 is present in the tetramerization domain.

                           10        20        30        40        50
                   ....*....|....*....|....*....|....*....|....*....|....*
gi 767939565   366 RSEFSSRSGYGEYVQQTLQPGMRVRMLDDYEEISAGDEGEFRQSNNGI---PPVQ 417
Cdd:pfam11515    1 RSDFASRDDYAEYVRDNLAPGMRVRCCRDYEEVSAGDEGEVIQSNRGGlhdLNVQ 55

In Between Ring fingers; the domains occurs between pairs og RING fingers

                            10        20        30        40        50        60
                    ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 767939565   2080 KYEKALLRGYVESCSNLTWCTNPqGCDRILCRQGL--GCGTTCSKCGWASCFNCSFPeAHYPASC 2142
Cdd:smart00647    2 KYERLLLESYVESNPDLKWCPAP-DCSAAIIVTEEegCNRVTCPKCGFSFCFRCKVP-WHSPVSC 64

IBR domain, a half RING-finger domain; The IBR (In Between Ring fingers) domain is often found to occur between pairs of ring fingers (pfam00097). This domain has also been called the C6HC domain and DRIL (for double RING finger linked) domain. Proteins that contain two Ring fingers and an IBR domain (these proteins are also termed RBR family proteins) are thought to exist in all eukaryotic organizms. RBR family members play roles in protein quality control and can indirectly regulate transcription. Evidence suggests that RBR proteins are often parts of cullin-containing ubiquitin ligase complexes. The ubiquitin ligase Parkin is an RBR family protein whose mutations are involved in forms of familial Parkinson's disease.

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 767939565  2080 KYEKALLRGYVESCSNLTWCTNPqGCDRILCRQGLGCGT---TCSKCGWASCFNCSFPeAHYPASC 2142
Cdd:pfam01485    2 KYEKLLLKSYVESDPNLKWCPTP-DCGYIIELTDGCSNTshvTCSKCGHEFCFNCKEE-WHEGLTC 65

Cullin protein neddylation domain; This is the neddylation site of cullin proteins which are a family of structurally related proteins containing an evolutionarily conserved cullin domain. With the exception of APC2, each member of the cullin family is modified by Nedd8 and several cullins function in Ubiquitin-dependent proteolysis, a process in which the 26S proteasome recognises and subsequently degrades a target protein tagged with K48-linked poly-ubiquitin chains. Cullins are molecular scaffolds responsible for assembling the ROC1/Rbx1 RING-based E3 ubiquitin ligases, of which several play a direct role in tumorigenesis. Nedd8/Rub1 is a small ubiquitin-like protein, which was originally found to be conjugated to Cdc53, a cullin component of the SCF (Skp1-Cdc53/CUL1-F-box protein) E3 Ub ligase complex in Saccharomyces cerevisiae, and Nedd8 modification has now emerged as a regulatory pathway of fundamental importance for cell cycle control and for embryogenesis in metazoans. The only identified Nedd8 substrates are cullins. Neddylation results in covalent conjugation of a Nedd8 moiety onto a conserved cullin lysine residue.

                            10        20        30        40        50        60        70        80
                    ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 767939565   1803 TLEQKRNLLSCLLVRILKAHGEkgLHIDQLVCLVLEAWQKGPNPpgtlghTVAggvactstDVLSCILHLLGQGYVKRRD 1882
Cdd:smart00884    1 VEEDRKLEIQAAIVRIMKSRKT--LSHSELVSEVIEQLKKRFKP------SVS--------DIKKRIESLIEREYLERDE 64

                    .
gi 767939565   1883 D 1883
Cdd:smart00884   65 D 65

Cullin;

                            10        20        30        40        50        60        70        80
                    ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 767939565   1532 FEHFYQHYMADRLLSFGS----------SWLEgavlEQIGLCFPNRLpQLMLQSLSTSEELQRQF-HLFQLQRLDKlfle 1600
Cdd:smart00182    8 FEKYYKKHLAKRLILNRSasddaeenmiTKLK----QECGYEFTSKL-ERMFRDISLSKDLNQSFkDMLENNPSAK---- 78

                            90       100       110       120       130       140       150       160
                    ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 767939565   1601 qedeeekrleeeeeeeeeeeaekelfiedPSPAISILVLSPRCWPVSPLCYLYHprkcLPTEFCDALDRFSSFYSQSQNh 1680
Cdd:smart00182   79 -----------------------------PIIDLNVRVLTSGYWPTSSTEVEIN----LPQELEDALEEFEEFYLAKHS- 124

                           170       180
                    ....*....|....*....|....
gi 767939565   1681 pvldmgpHRRLQWTW-LGRAELQF 1703
Cdd:smart00182  125 -------GRKLTWLHsLGRGEVKA 141

APC10-like DOC1 domain of CUL7, subunit of the SCF-ROC1-like E3 ubiquitin ligase complex that mediates substrate ubiquitination; This model represents the APC10/DOC1 domain present in CUL7, a subunit of the SCF-ROC1-like E3 Ubiquitin (Ub) ligase complex, which mediates substrate ubiquitination (or ubiquitylation), and is a component of the ubiquitin-26S proteasome pathway for selective proteolytic degradation. CUL7 is a member of the Cullin-RING ligase family and functions as a molecular scaffold assembling the SCF-ROC1-like E3 Ub ligase complex consisting of the adapter protein Skp1, CUL7, the WD40 repeat-containing F-box Fbw8 (also known as Fbx29), and ROC1 (RING-box protein 1). CUL7 is a large protein with a C-terminal cullin domain that binds ROC1 and additional domains, including an APC10/DOC1 domain. While the Fbw8 protein is responsible for substrate protein recognition, the ROC1 RING domain recruits an Ub-charged E2 Ub-conjugating enzyme for substrate ubiquitination. It remains to be determined how CUL7 binds to the Skp1-Fbw8 heterodimer. The CUL7 E3 Ub ligase has been implicated in the proteasomal degradation of the cellular proteins, cyclin D1, an important regulator of the G1 to S-phase cell cycle progression, and insulin receptor substrate 1, a critical component of the signaling pathways downstream of the insulin and insulin-like growth factor 1 receptor. CUL7 appears to be an important regulator of placental development. Germ line mutations of CUL7 are linked to 3-M syndrome and Yakuts short stature syndrome.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 767939565 1057 DKCWEKVEVSSNPHRASKLTDHNPKTYWESNGSTGSHYITLHMHRGVLVRQLTLLVASEDSSYMPARVVVFGGDSTSCIG 1136
Cdd:cd08665     1 DKCWEKVEVSSNPHRANKLTDGNPKTYWESNGSTGSHYINIHMHRGVVIRQLYMLVASEDSSYMPARVVVLGGDSPSCIT 80

                          90       100       110       120       130
                  ....*....|....*....|....*....|....*....|....*....|.
gi 767939565 1137 TELNTVNVMPSASRVILLENLNRFWPIIQIRIKRCQQGGIDTRVRGVEVLG 1187
Cdd:cd08665    81 TELNAVNVSPTASRVVLLENMTRFWPIIQIRIKRCQQGGIDTRVRGLEILG 131

APC10-like DOC1 domains in E3 ubiquitin ligases that mediate substrate ubiquitination; This family contains the single domain protein, APC10, a subunit of the anaphase-promoting complex (APC), as well as the DOC1 domain of multi-domain proteins present in E3 ubiquitin ligases. E3 ubiquitin ligases mediate substrate ubiquitination (or ubiquitylation), a component of the ubiquitin-26S proteasome pathway for selective proteolytic degradation. The APC, a multi-protein complex (or cyclosome), is a cell cycle-regulated, E3 ubiquitin ligase that controls important transitions in mitosis and the G1 phase by ubiquitinating regulatory proteins, thereby targeting them for degradation. APC10-like DOC1 domains such as those present in HECT (Homologous to the E6-AP Carboxyl Terminus) and Cullin-RING (Really Interesting New Gene) E3 ubiquitin ligase proteins, HECTD3, and CUL7, respectively, are also included in this hierarchy. CUL7 is a member of the Cullin-RING ligase family and functions as a molecular scaffold assembling a SCF-ROC1-like E3 ubiquitin ligase complex consisting of Skp1, CUL7, Fbx29 F-box protein, and ROC1 (RING-box protein 1) and promotes ubiquitination. CUL7 is a multi-domain protein with a C-terminal cullin domain that binds ROC1 and a centrally positioned APC10/DOC1 domain. HECTD3 contains a C-terminal HECT domain which contains the active site for ubiquitin transfer onto substrates, and an N-terminal APC10 domain which is responsible for substrate recognition and binding. An APC10/DOC1 domain homolog is also present in HERC2 (HECT domain and RLD2), a large multi-domain protein with three RCC1-like domains (RLDs), additional internal domains including zinc finger ZZ-type and Cyt-b5 (Cytochrome b5-like Heme/Steroid binding) domains, and a C-terminal HECT domain. Recent studies have shown that the protein complex HERC2-RNF8 coordinates ubiquitin-dependent assembly of DNA repair factors on damaged chromosomes. Also included in this hierarchy is an uncharacterized APC10/DOC1-like domain found in a multi-domain protein, which also contains CUB, zinc finger ZZ-type, and EF-hand domains. The APC10/DOC1 domain forms a beta-sandwich structure that is related in architecture to the galactose-binding domain-like fold; their sequences are quite dissimilar, however, and are not included here.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 767939565 1058 KCW-EKVEVSSNPHRASKLTDHNPKTYWESNGSTGSHYITLHMHRGVLVRQLTLLVASEDSSYMPARVVVFGGDSTSCIg 1136
Cdd:cd08159     1 KCYtASIEVSSNPLPVSRLTDGNYDTYWQSDGSQGSHWIRLFMKKDVLIRVLAIFVDMADSSYMPSLVVVYGGHSPSDL- 79

                          90       100       110       120       130
                  ....*....|....*....|....*....|....*....|....*....|
gi 767939565 1137 TELNTVNVMPSASRVILLENLNRFWPIIQIRIKRCQQGGIDTRVRGVEVL 1186
Cdd:cd08159    80 RELKDVNIRPSNGWVALLEDDTLKCPYIEIRIKRCRSDGIDTRIRGLRLL 129

Rcat domain found in cullin-9 (CUL-9) and similar proteins; CUL-9, also called UbcH7-associated protein 1 (H7-AP1), p53-associated parkin-like cytoplasmic protein, or PARC, is a cytoplasmic RBR-type E3 ubiquitin-protein ligase that function as a tumor suppressor and promotes p53-dependent apoptosis. It mediates the ubiquitination and degradation of cytosolic cytochrome c to promote survival in neurons and cancer cells. It is also a critical downstream effector of the 3M complex in the maintenance of microtubules and genome integrity. Moreover, CUL-9, together with CUL-7, forms homodimers and heterodimers, as well as some atypical cullin RING ligase complexes, which may exhibit ubiquitin ligase activity. CUL-9 contains a CPH domain (conserved in Cul7, PARC, and HERC2 proteins), a DOC (DOC1/APC10) domain, cullin homology domains linked with E3 ligase function, and a C-terminal RBR domain previously known as RING-BetweenRING-RING domain or TRIAD [two RING fingers and a DRIL (double RING finger linked)] domain. Based on current understanding of the structural biology of RBR ligases, the nomenclature of RBR has been changed to RING1-BRcat (benign-catalytic)-Rcat (required-for-catalysis) recently. The RBR domain uses an auto-inhibitory mechanism to modulate ubiquitination activity, as well as a hybrid mechanism that combines aspects from both RING and HECT E3 ligase functions to facilitate the ubiquitination reaction. This model corresponds to the Rcat domain of CUL-9 that is essential for RBR E3 ligase activity and adopts the same fold as the BRcat domain.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*...
gi 767939565 2166 HLAKLISKRCPSCQAPIEKNEGCLHMTCAKCNHGFCWRCLKSWKPNHKDYYNCSAMVS 2223
Cdd:cd20359     1 HLAKLISKRCPSCQAQIEKNEGCLHMTCAKCNHGFCWRCLKPWKPTHKDYYNCSAMVS 58

APC10-like DOC1 domain of HECTD3, a HECT E3 ubiquitin ligase protein that mediates substrate ubiquitination; This model represents the APC10/DOC1 domain present in HECTD3, a HECT (Homologous to the E6-AP Carboxyl Terminus) E3 ubiquitin ligase protein. HECT E3 ubiquitin ligases mediate substrate ubiquitination (or ubiquitylation), and are a component of the ubiquitin-26S proteasome pathway for selective proteolytic degradation. They also regulate the trafficking of many receptors, channels, transporters and viral proteins. HECTD3 (HECT domain-containing protein3) contains a C-terminal HECT domain with the active site for ubiquitin transfer onto substrates, and an N-terminal APC10/DOC1 domain, which is responsible for substrate recognition and binding. HECTD3 specifically recognizes the Trio-binding protein, Tara (Trio-associated repeat on actin), implicated in regulating actin cytoskeletal, cell motility and cell growth. Tara also binds to TRF1 and may participate in telomere maintenance and/or mitotic regulation through interacting with TRF1. HECTD3 interacts with and promotes the ubiquitination of Syntaxin 8, an endosomal syntaxin proposed to mediate distinct steps of endosomal protein trafficking. HECTD3-mediated Syntaxin 8 degradation has been suggested to contribute to the pathophysiology of neurodegenerative diseases.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 767939565 1061 EKVEVSS--NPHRASKLTDHNPKTYWESNGSTGSHYITLHMHRGVLVRQLTLLVASEDSSYMPARVVVFGGDSTSCigTE 1138
Cdd:cd08666     8 ESIEVSSytDDFNVSCLTDGDPDTYWESDGSQGQHWIRLHMKKGTIIKKLLLTVDATDDNYMPKRVAVYGGEGDNL--KK 85

                          90       100       110       120
                  ....*....|....*....|....*....|....*....|....*...
gi 767939565 1139 LNTVNV-MPSASRVILLENLNRFWPIIQIRIKRCQQGGIDTRVRGVEV 1185
Cdd:cd08666    86 LNDVSIdETLIGDVCILEDMTTHLPVIEIRIKECKDEGIDVRIRGIKI 133

RING finger, HC subclass, found in cullin-9 (CUL-9) and similar proteins; CUL-9, also known as UbcH7-associated protein 1 (H7-AP1), p53-associated parkin-like cytoplasmic protein, or PARC, is a cytoplasmic RBR-type E3 ubiquitin-protein ligase that is a tumor suppressor and promotes p53-dependent apoptosis. It mediates the ubiquitination and degradation of cytosolic cytochrome c to promote survival in neurons and cancer cells. It is also a critical downstream effector of the 3M complex in the maintenance of microtubules and genome integrity. Moreover, CUL-9, together with CUL-7, forms homodimers and heterodimers, as well as some atypical cullin RING ligase complexes, which may exhibit ubiquitin ligase activity. CUL-9 contains a CPH domain (Cul7, PARC, and HERC2), a DOC (DOC1/APC10) domain, cullin homology (CH) domains linked with E3 ligase function, and a C-terminal RBR domain previously known as RING-BetweenRING-RING domain or TRIAD [two RING fingers and a DRIL (double RING finger linked)] domain. Based on current understanding of the structural biology of RBR ligases, the nomenclature of RBR has been corrected as RING-BRcat (benign-catalytic)-Rcat (required-for-catalysis) recently. The RBR (RING1-BRcat-Rcat) domain uses an auto-inhibitory mechanism to modulate ubiquitination activity, as well as a hybrid mechanism that combines aspects from both RING and HECT E3 ligase function to facilitate the ubiquitination reaction. This model corresponds to the RING domain, a C3HC4-type RING-HC finger required for RBR-mediated ubiquitination.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 767939565 2007 DHCPVCVSPLGCDDDLPSLCCMHYCCKSCWNEYLTTRIEQNLVLNCTCPIADC 2059
Cdd:cd16624     1 THCPVCVSQLSPDEPLPTLCCMHYCCKSCWKEYLTTRIEQNLVLNCTCPITDC 53

Rcat domain found in two RING fingers and DRIL [double RING finger linked] 1 (TRIAD1); TRIAD1, also called ariadne-2 (ARI-2), protein ariadne-2 homolog, Ariadne RBR E3 ubiquitin protein ligase 2 (ARIH2), or UbcM4-interacting protein 48, is an RBR-type E3 ubiquitin-protein ligase that catalyzes the formation of polyubiquitin chains linked via lysine-48 as well as lysine-63 residues. Its auto-ubiquitylation can be catalyzed by the E2 conjugating enzyme UBCH7. TRIAD1 has been implicated in hematopoiesis, specifically in myelopoiesis, as well as in embryogenesis. It functions as a regulator of endosomal transport, and is required for the proper function of multivesicular bodies. It also acts as a novel ubiquitination target for proteasome-dependent degradation by murine double minute 2 (MDM2). As a proapoptotic protein, TRIAD1 promotes p53 activation, and inhibits MDM2-mediated p53 ubiquitination and degradation. Furthermore, TRIAD1 can inhibit the ubiquitination and proteasomal degradation of growth factor independence 1 (Gfi1), a transcriptional repressor essential for the function and development of many different hematopoietic lineages. TRIAD1 contains an RBR domain that was previously known as RING-BetweenRING-RING domain or TRIAD [two RING fingers and a DRIL (double RING finger linked)] domain. Based on current understanding of the structural biology of RBR ligases, the nomenclature of RBR has been changed to RING1-BRcat (benign-catalytic)-Rcat (required-for-catalysis) recently. The RBR domain uses an auto-inhibitory mechanism to modulate ubiquitination activity, as well as a hybrid mechanism that combines aspects from both RING and HECT E3 ligase functions to facilitate the ubiquitination reaction. This model corresponds to the Rcat domain of TRIAD1 that is essential for RBR E3 ligase activity and adopts the same fold as the BRcat domain.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*...
gi 767939565 2172 SKRCPSCQAPIEKNEGCLHMTCAKCNHGFCWRCLKSWKPNHKDYYNCS 2219
Cdd:cd20360     3 TKDCPKCHVCIEKNGGCNHMQCSKCKHEFCWMCLGDWKTHGSEYYECS 50

Rcat domain found in ankyrin repeat and IBR domain-containing protein 1 (ANKIB1) and similar proteins; ANKIB1 is an RBR-type E3 ubiquitin-protein ligase that may function as part of an E3 complex, which accepts ubiquitin from specific E2 ubiquitin-conjugating enzymes and then transfers it to substrates. It contains N-terminal ankyrin repeats, and an RBR domain that was previously known as RING-BetweenRING-RING domain or TRIAD [two RING fingers and a DRIL (double RING finger linked)] domain. Based on current understanding of the structural biology of RBR ligases, the nomenclature of RBR has been changed to RING1-BRcat (benign-catalytic)-Rcat (required-for-catalysis) recently. The RBR domain uses an auto-inhibitory mechanism to modulate ubiquitination activity, as well as a hybrid mechanism that combines aspects from both RING and HECT E3 ligase functions to facilitate the ubiquitination reaction. This model corresponds to the Rcat domain of ANKIB1 that is essential for RBR E3 ligase activity and adopts the same fold as the BRcat domain.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 767939565 2172 SKRCPSCQAPIEKNEGCLHMTCAKCNHGFCWRCLKSWK---PNHKDYYNC 2218
Cdd:cd20361     9 SKPCPNCKSPIQKNEGCNHMKCSKCKYDFCWVCLEEWKkhsSSTGGYFRC 58

Rcat domain found in E3 ubiquitin-protein ligase ARI7 and similar proteins; This subfamily contains probable RBR-type E3 ubiquitin-protein ligases (EC 2.3.2.31) including Arabidopsis thaliana ARI5, ARI6, ARI7, and ARI8, as well as Dictyostelium discoideum RbrA (also called Ariadne-like ubiquitin ligase). They may function as part of E3 complexes, which accept ubiquitin from E2 ubiquitin-conjugating enzymes and then transfer it to substrates. RbrA may be required for normal cell-type proportioning and cell sorting during multicellular development, and is also necessary for spore cell viability. Members of this subfamily contain an RBR domain that was previously known as RING-BetweenRING-RING domain or TRIAD [two RING fingers and a DRIL (double RING finger linked)] domain. Based on current understanding of the structural biology of RBR ligases, the nomenclature of RBR has been changed to RING1-BRcat (benign-catalytic)-Rcat (required-for-catalysis) recently. The RBR domain uses an auto-inhibitory mechanism to modulate ubiquitination activity, as well as a hybrid mechanism that combines aspects from both RING and HECT E3 ligase functions to facilitate the ubiquitination reaction. This model corresponds to the Rcat domain of ARI7-like proteins that are essential for RBR E3 ligase activity and adopt the same fold as the BRcat domain.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 767939565 2172 SKRCPSCQAPIEKNEGCLHMTC-AKCNHGFCWRCLKSWKpNHKD----YYNCS 2219
Cdd:cd22583     2 TKPCPKCKRPIEKNQGCMHMTCsPPCKHEFCWLCLGPWS-EHGErtggFYACN 53

Cullin family;

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 767939565  1485 SEQFARYIDQQIQGGLIGGAPGvemlgQLQRHLEPIMVL----SGLELattFEHFYQHYMADRLLSFGS----------S 1550
Cdd:pfam00888  353 PELLAKYIDDLLKKGLKGKSEE-----ELEEKLDKVITLfryiQDKDV---FEAFYKKHLAKRLLLGKSasddaersmiS 424

                           90       100       110       120       130       140       150       160
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 767939565  1551 WLEGAVleqiGLCFPNRLpQLMLQSLSTSEELQRQFhlfqlqrldKLFLEQEDEeekrleeeeeeeeeeeaekelfiEDP 1630
Cdd:pfam00888  425 KLKEEC----GSEFTSKL-EGMFKDMELSKDLMKEF---------KEHLSENKS-----------------------SKK 467

                          170       180       190       200       210       220       230       240
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 767939565  1631 SPAISILVLSPRCWPvsplcyLYHPRKC-LPTEFCDALDRFSSFYSQSQNHpvldmgphRRLQWTW-LGRAEL--QFGK- 1705
Cdd:pfam00888  468 GIDLSVNVLTSGAWP------TYLTSDFiLPPELEKAIERFEKFYLSKHSG--------RKLTWLHsLGTAELkaTFPKg 533

                          250       260       270       280       290
                   ....*....|....*....|....*....|....*....|....*....|.
gi 767939565  1706 --QILHVSTVQMWLLLKFNQT-EEVSVETLLKDSDLSPELLLQALVPLTSG 1753
Cdd:pfam00888  534 kkHELNVSTYQMAILLLFNDDgDSLSYEEIQEATGLPDEELKRTLQSLACA 584

In Between Ring fingers; the domains occurs between pairs og RING fingers

                            10        20        30        40        50        60
                    ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 767939565   2080 KYEKALLRGYVESCSNLTWCTNPqGCDRILCRQGL--GCGTTCSKCGWASCFNCSFPeAHYPASC 2142
Cdd:smart00647    2 KYERLLLESYVESNPDLKWCPAP-DCSAAIIVTEEegCNRVTCPKCGFSFCFRCKVP-WHSPVSC 64

Rcat domain found in an uncharacterized subfamily of RBR proteins; This subfamily contains uncharacterized members of the RBR family, including Arabidopsis thaliana mutator-like transposase and hypothetical protein At2g19610/F3P11.21. The RBR family of RING-type E3 ligases are characterized by containing a RBR domain, which was previously known as RING-BetweenRING-RING domain or TRIAD [two RING fingers and a DRIL (double RING finger linked)] domain. It is composed of an extended RING domain (RING1) followed by an in-between RING (IBR) domain and the catalytic domain, which is structurally an IBR domain but is commonly designated RING2. Based on current understanding of the structural biology of RBR ligases, the nomenclature of RBR has been corrected as RING1-BRcat (benign-catalytic)-Rcat (required-for-catalysis) recently, where the IBR and RING2 domains have been renamed as BRcat and Rcat domains, respectively. The RBR domain uses an auto-inhibitory mechanism to modulate ubiquitination activity, as well as a hybrid mechanism that combines aspects from both RING and HECT E3 ligase functions to facilitate the ubiquitination reaction. RBR family members play roles in protein quality control and can indirectly regulate transcription. Evidence suggests that RBR proteins are often parts of cullin-containing ubiquitin ligase complexes. This model corresponds to the Rcat domain that is essential for RBR E3 ligase activity and adopts the same fold as the BRcat domain.

                          10        20        30
                  ....*....|....*....|....*....|....*.
gi 767939565 2173 KRCPSCQAPIEKNEGCLHMTCaKCNHGFCWRCLKSW 2208
Cdd:cd22584     3 RRCPQCGHMVELSEGCNHMTC-RCGYEFCYLCGAPW 37

APC10 subunit of the anaphase-promoting complex (APC) that mediates substrate ubiquitination; This model represents the single domain protein APC10, a subunit of the anaphase-promoting complex (APC), which is a multi-subunit E3 ubiquitin ligase. E3 ubiquitin ligases mediate substrate ubiquitination (or ubiquitylation), a vital component of the ubiquitin-26S proteasome pathway for selective proteolytic degradation. The APC (also known as the cyclosome), is a cell cycle-regulated E3 ubiquitin ligase that controls important transitions in mitosis and the G1 phase by ubiquitinating regulatory proteins, thereby targeting them for degradation. In mitosis, the APC initiates sister chromatid separation by ubiquitinating the anaphase inhibitor securin and triggers exit from mitosis by ubiquitinating cyclin B. The C-terminus of APC10 binds to CDC27/APC3, an APC subunit that contains multiple tetratrico peptide repeats. APC10 domains are homologous to the DOC1 domains present in the HECT (Homologous to the E6-AP Carboxyl Terminus) E3 ubiquitin ligase protein, and the Cullin-RING (Really Interesting New Gene) E3 ubiquitin ligase complex. The APC10/DOC1 domain forms a beta-sandwich structure that is related in architecture to the galactose-binding domain-like fold; their sequences are quite dissimilar, however, and are not included here.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 767939565 1075 LTDHNPKTYWESNGSTgSHYITLHMHRGVLVRQLTLLVA-SEDSSYMPARVVVFGGDSTSCIgTELNTVNV-MPSASRVI 1152
Cdd:cd08366    23 LRDDSLDTYWQSDGPQ-PHLINIQFSKKTDISAVALYLDyKLDESYTPSKISIRAGTSPHDL-QEVRTVELeEPNGWVHI 100

                          90       100       110
                  ....*....|....*....|....*....|....*....
gi 767939565 1153 LLENLNRFWPI----IQIRIKRCQQGGIDTRVRGVEVLG 1187
Cdd:cd08366   101 PLEDNRDGKPLrtffLQIAILSNHQNGRDTHIRQIKVYG 139

IBR domain, a half RING-finger domain; The IBR (In Between Ring fingers) domain is often found to occur between pairs of ring fingers (pfam00097). This domain has also been called the C6HC domain and DRIL (for double RING finger linked) domain. Proteins that contain two Ring fingers and an IBR domain (these proteins are also termed RBR family proteins) are thought to exist in all eukaryotic organizms. RBR family members play roles in protein quality control and can indirectly regulate transcription. Evidence suggests that RBR proteins are often parts of cullin-containing ubiquitin ligase complexes. The ubiquitin ligase Parkin is an RBR family protein whose mutations are involved in forms of familial Parkinson's disease.

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 767939565  2080 KYEKALLRGYVESCSNLTWCTNPqGCDRILCRQGLGCGT---TCSKCGWASCFNCSFPeAHYPASC 2142
Cdd:pfam01485    2 KYEKLLLKSYVESDPNLKWCPTP-DCGYIIELTDGCSNTshvTCSKCGHEFCFNCKEE-WHEGLTC 65

BRcat domain found in human homolog of Drosophila Ariadne (HHARI) and similar proteins; This subfamily includes Drosophila melanogaster protein ariadne-1 (ARI-1), and its eukaryotic homologs, such as HHARI. ARI-1 is a widely expressed Drosophila RING-finger protein that localizes mainly in the cytoplasm, and is required for neural development. It interacts with the ubiquitin-conjugating enzyme, UbcD10. HHARI is also called H7-AP2, monocyte protein 6 (MOP-6), protein ariadne-1 homolog, Ariadne RBR E3 ubiquitin protein ligase 1 (ARIH1), ariadne-1 (ARI-1), UbcH7-binding protein, UbcM4-interacting protein, or ubiquitin-conjugating enzyme E2-binding protein 1. It is an RBR-type E3 ubiquitin-protein ligase highly expressed in nuclei, where it is co-localized with nuclear bodies including Cajal, PML, and Lewy bodies. It interacts with the E2 conjugating enzymes UbcH7, UbcH8, UbcM4, and UbcD10 in human, mouse and fly, and modulates the ubiquitylation of substrate proteins including single-minded 2 (SIM2) and translation initiation factor 4E homologous protein (4EHP). It functions as a potent mediator of DNA damage-induced translation arrest, which protects stem and cancer cells against genotoxic stress by initiating a 4EHP-mediated mRNA translation arrest. HHARI contains an RBR domain that was previously known as RING-BetweenRING-RING domain or TRIAD [two RING fingers and a DRIL (double RING finger linked)] domain. Based on current understanding of the structural biology of RBR ligases, the nomenclature of RBR has been changed to RING1-BRcat (benign-catalytic)-Rcat (required-for-catalysis) recently. The RBR domain uses an auto-inhibitory mechanism to modulate ubiquitination activity, as well as a hybrid mechanism that combines aspects from both RING and HECT E3 ligase functions to facilitate the ubiquitination reaction. This model corresponds to the BRcat domain of HHARI and similar proteins that adopt the same fold as the Rcat domain while lacking the catalytic cysteine residue and ubiquitination activity.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 767939565 2074 SPEVISKYEKALLRGYVESCSNLTWCTNPqGCDRILCRQGLGC-GTTCsKCGWASCFNCSfPEAHYPASCGHMSQWV 2149
Cdd:cd20343     1 DSKVRLKYQHLITNSFVECNRLLKWCPAP-DCGHAVKVQYPDArPVTC-KCGHTFCFACG-ENWHEPVKCRLLKKWI 74

Rcat domain found in RING finger protein 144A (RNF144A); RNF144A, also called UbcM4-interacting protein 4 (UIP4), or ubiquitin-conjugating enzyme 7-interacting protein 4, is a transmembrane (TM) domain-containing RBR-type E3 ubiquitin-protein ligase that targets DNA-dependent protein kinase catalytic subunit (DNA-PKcs), and thus promotes DNA damage-induced cell apoptosis. It is transcriptionally repressed by metastasis-associated protein 1 (MTA1) and inhibits MTA1-driven cancer cell migration and invasion. RNF144A contains an RBR domain followed by a potential single-TM domain. The RBR domain was previously known as RING-BetweenRING-RING domain or TRIAD [two RING fingers and a DRIL (double RING finger linked)] domain. Based on current understanding of the structural biology of RBR ligases, the nomenclature of RBR has been changed to RING1-BRcat (benign-catalytic)-Rcat (required-for-catalysis) recently. The RBR domain uses an auto-inhibitory mechanism to modulate ubiquitination activity, as well as a hybrid mechanism that combines aspects from both RING and HECT E3 ligase functions to facilitate the ubiquitination reaction. This model corresponds to the Rcat domain of RNF144A that is essential for RBR E3 ligase activity and adopts the same fold as the BRcat domain.

                          10        20        30
                  ....*....|....*....|....*....|....*
gi 767939565 2173 KRCPSCQAPIEKNEGCLHMTCAKCNHGFCWRCLKS 2207
Cdd:cd20368     7 KRCPKCKVYIERDEGCAQMMCKNCKHAFCWYCLES 41

Rcat domain found in RING finger protein 217 (RNF217); RNF217, also called IBR domain-containing protein 1 (IBRDC1), is a transmembrane (TM) domain-containing RBR-type E3 ubiquitin-protein ligase, with different splice variants, that is mainly expressed in testis and skeletal muscle. It interacts with the anti-apoptotic protein HAX1, and is adjacent to a translocation breakpoint involving ETV6 in childhood acute lymphoblastic leukemia (ALL). RNF217 contains an RBR domain followed by TMs. The RBR domain was previously known as RING-BetweenRING-RING domain or TRIAD [two RING fingers and a DRIL (double RING finger linked)] domain. Based on current understanding of the structural biology of RBR ligases, the nomenclature of RBR has been changed to RING1-BRcat (benign-catalytic)-Rcat (required-for-catalysis) recently. The RBR domain uses an auto-inhibitory mechanism to modulate ubiquitination activity, as well as a hybrid mechanism that combines aspects from both RING and HECT E3 ligase functions to facilitate the ubiquitination reaction. This model corresponds to the Rcat domain of RNF217 that is essential for RBR E3 ligase activity and adopts the same fold as the BRcat domain.

                          10        20        30
                  ....*....|....*....|....*....|..
gi 767939565 2173 KRCPSCQAPIEKNEGCLHMTCAKCNHGFCWRC 2204
Cdd:cd20350     6 QKCPKCKVYIQRSEGCDHMTCSQCNTNFCYRC 37

BRcat (benign-catalytic) and Rcat (required-for-catalysis) domains, part of the RBR (RING1-BRcat-Rcat) domain; The RBR family of RING-type E3 ligases are characterized by containing an RBR (RING1-BRcat-Rcat) domain, which was previously known as RING-BetweenRING-RING domain or TRIAD [two RING fingers and a DRIL (double RING finger linked)] domain. It is composed of an extended RING domain (RING1) followed by an in-between RING (IBR) domain and the catalytic domain, which is structurally an IBR domain but is commonly designated as RING2. Based on current understanding of the structural biology of RBR ligases, the nomenclature of RBRs has been changed to RING1-BRcat (benign-catalytic)-Rcat (required-for-catalysis), where the IBR and RING2 domains have been renamed as BRcat and Rcat domains, respectively. The RBR domain uses an auto-inhibitory mechanism to modulate ubiquitination activity, as well as a hybrid mechanism that combines aspects from both RING and HECT E3 ligase functions to facilitate the ubiquitination reaction. The BRcat domain adopts the same fold as the Rcat domain while lacking the catalytic cysteine residue and ubiquitination activity. RBR family members play roles in protein quality control and can indirectly regulate transcription. Evidence suggests that RBR proteins are often parts of cullin-containing ubiquitin ligase complexes.

                          10        20        30
                  ....*....|....*....|....*....|...
gi 767939565 2173 KRCPSCQAPIEKNEGCLHMTCAKCNHGFCWRCL 2205
Cdd:cd14799     3 KWCPKCHFGFEKERGCMHATCPQCRQEFCWRCK 35

Cullin protein neddylation domain; This is the neddylation site of cullin proteins which are a family of structurally related proteins containing an evolutionarily conserved cullin domain. With the exception of APC2, each member of the cullin family is modified by Nedd8 and several cullins function in Ubiquitin-dependent proteolysis, a process in which the 26S proteasome recognises and subsequently degrades a target protein tagged with K48-linked poly-ubiquitin chains. Cullins are molecular scaffolds responsible for assembling the ROC1/Rbx1 RING-based E3 ubiquitin ligases, of which several play a direct role in tumorigenesis. Nedd8/Rub1 is a small ubiquitin-like protein, which was originally found to be conjugated to Cdc53, a cullin component of the SCF (Skp1-Cdc53/CUL1-F-box protein) E3 Ub ligase complex in Saccharomyces cerevisiae, and Nedd8 modification has now emerged as a regulatory pathway of fundamental importance for cell cycle control and for embryogenesis in metazoans. The only identified Nedd8 substrates are cullins. Neddylation results in covalent conjugation of a Nedd8 moiety onto a conserved cullin lysine residue.

                            10        20        30        40        50        60        70        80
                    ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 767939565   1803 TLEQKRNLLSCLLVRILKAHGEkgLHIDQLVCLVLEAWQKGPNPpgtlghTVAggvactstDVLSCILHLLGQGYVKRRD 1882
Cdd:smart00884    1 VEEDRKLEIQAAIVRIMKSRKT--LSHSELVSEVIEQLKKRFKP------SVS--------DIKKRIESLIEREYLERDE 64

                    .
gi 767939565   1883 D 1883
Cdd:smart00884   65 D 65

Anaphase-promoting complex, subunit 10 (APC10);

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 767939565  1075 LTDHNPKTYWESNGSTgSHYITLHMHRGVLVRQLTLLVASE-DSSYMPARVVVFGGDSTSCIgTELNTVNV-MPSA-SRV 1151
Cdd:pfam03256   45 LRDDNLDTYWQSDGSQ-PHLVNIQFRKKTPVKYVAIYLDYKlDESYTPSKISVRAGTGFNDL-QEVRVVDLeEPTGwVHI 122

                           90       100       110
                   ....*....|....*....|....*....|....*....
gi 767939565  1152 ILLENLNRFWPI--IQIRIKRCQQGGIDTRVRGVEVLGP 1188
Cdd:pfam03256  123 PLRDANGKPLRTfmLQIAVLSNHQNGRDTHVRQIKIYGP 161

BRcat (benign-catalytic) domain, part of the RBR (RING1-BRcat-Rcat) domain; The RBR family of RING-type E3 ligases are characterized by containing an RBR domain, which was previously known as RING-BetweenRING-RING domain or TRIAD [two RING fingers and a DRIL (double RING finger linked)] domain. It is composed of an extended RING domain (RING1) followed by an in-between RING (IBR) domain and the catalytic domain, which is structurally an IBR domain but is commonly designated as RING2. Based on current understanding of the structural biology of RBR ligases, the nomenclature of RBR has been changed to RING1-BRcat (benign-catalytic)-Rcat (required-for-catalysis) recently, where the IBR and RING2 domains have been renamed as BRcat and Rcat domains, respectively. The RBR domain uses an auto-inhibitory mechanism to modulate ubiquitination activity, as well as a hybrid mechanism that combines aspects from both RING and HECT E3 ligase functions to facilitate the ubiquitination reaction. The BRcat domain adopts the same fold as the Rcat domain while lacking the catalytic cysteine residue and ubiquitination activity. RBR family members play roles in protein quality control and can indirectly regulate transcription. Evidence suggests that RBR proteins are often parts of cullin-containing ubiquitin ligase complexes. The model corresponds to the BRcat domain.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 767939565 2093 CSNLTWCTNPqGCDRILCRQGLGCGT--TCSKCGWASCFNCSFpEAHYPASCGHM 2145
Cdd:cd20335     1 NPNLRWCPTP-DCGGVIRVEEPGDGPrvTCPSCGTSFCFKCKE-EWHEGLTCEEY 53

RING finger, HC subclass, found in ankyrin repeat and IBR domain-containing protein 1 (ANKIB1) and similar proteins; ANKIB1 is an RBR-type E3 ubiquitin-protein ligase that may function as part of an E3 complex, which accepts ubiquitin from specific E2 ubiquitin-conjugating enzymes and then transfers it to substrates. It contains an N-terminal ankyrin repeat domain and an RBR domain that was previously known as RING-BetweenRING-RING domain or TRIAD [two RING fingers and a DRIL (double RING finger linked)] domain. Based on current understanding of the structural biology of RBR ligases, the nomenclature of RBR has been corrected as RING-BRcat (benign-catalytic)-Rcat (required-for-catalysis) recently. The RBR (RING1-BRcat-Rcat) domain uses an auto-inhibitory mechanism to modulate ubiquitination activity, as well as a hybrid mechanism that combines aspects from both RING and HECT E3 ligase function to facilitate the ubiquitination reaction. This model corresponds to the RING domain, a C3HC4-type RING-HC finger required for RBR-mediated ubiquitination.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 767939565 2009 CPVCVSPLGCDDDLPSLCCMHYCCKSCWNEYLTTRIEQNLVLNCTCPIADC 2059
Cdd:cd16774     3 CDICMCSISVFEDPVDMPCGHEFCRACWEGYLNLKIQEGEAHNIFCPAYDC 53

RING finger, HC subclass, found in Saccharomyces cerevisiae histone E3 ligase 2 (HEL2) and similar proteins; HEL2 is an E3 ubiquitin-protein ligase that interacts with the E2 ubiquitin-conjugating enzyme UBC4 and histones H3 and H4. It plays an important role in regulating histone protein levels and also likely to contribute to the maintenance of genomic stability in the budding yeast. HEL2 can be phosphorylated by the DNA damage checkpoint kinase and histone protein regulator Rad53. This subfamily also includes Schizosaccharomyces pombe histone E3 ligase 1 (HEL1), also known as DNA-break-localizing protein 4 (dbl4), and Dictyostelium discoideum Ariadne-like ubiquitin ligase (RbrA). RbrA may act as an E3 ubiquitin-protein ligase that appears to be required for normal cell-type proportioning and cell sorting during multicellular development, and is also necessary for spore cell viability. Members of this subfamily contain an RBR domain that was previously known as RING-BetweenRING-RING domain or TRIAD [two RING fingers and a DRIL (double RING finger linked)] domain. Based on current understanding of the structural biology of RBR ligases, the nomenclature of RBR has been corrected as RING-BRcat (benign-catalytic)-Rcat (required-for-catalysis) recently. The RBR (RING1-BRcat-Rcat) domain uses an auto-inhibitory mechanism to modulate ubiquitination activity, as well as a hybrid mechanism that combines aspects from both RING and HECT E3 ligase function to facilitate the ubiquitination reaction. This model corresponds to the RING domain, a C3HC4-type RING-HC finger required for RBR-mediated ubiquitination.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 767939565 2009 CPVCvsplgCDD---DLPSLCCMHYCCKSCWNEYLTTRI-EQNLVLNCTCPIADC 2059
Cdd:cd16625     3 CPIC-----CDDgelETFSLECGHEFCVDCYSQYLTSKIkEEGEGCRITCPGEKC 52

Rcat domain found in RING finger protein 19B (RNF19B); RNF19B, also called IBR domain-containing protein 3, or natural killer (NK) lytic-associated molecule (NKLAM), is a transmembrane (TM) domain-containing RBR-type E3 ubiquitin-protein ligase that plays a role in controlling tumor dissemination and metastasis. It is involved in the cytolytic function of NK cells and cytotoxic T lymphocytes (CTLs). It interacts with ubiquitin conjugates UbcH7 and UbcH8, and ubiquitinates uridine kinase like-1 protein, targeting it for degradation. Moreover, RNF19B is a novel component of macrophage phagosomes and plays a role in macrophage anti-bacterial activity. It functions as a novel modulator of macrophage inducible nitric oxide synthase (iNOS) expression. RNF19B contains an RBR domain followed by three TMs. The RBR domain was previously known as RING-BetweenRING-RING domain or TRIAD [two RING fingers and a DRIL (double RING finger linked)] domain. Based on current understanding of the structural biology of RBR ligases, the nomenclature of RBR has been changed to RING1-BRcat (benign-catalytic)-Rcat (required-for-catalysis) recently. The RBR domain uses an auto-inhibitory mechanism to modulate ubiquitination activity, as well as a hybrid mechanism that combines aspects from both RING and HECT E3 ligase functions to facilitate the ubiquitination reaction. This model corresponds to the Rcat domain of RNF19B that is essential for RBR E3 ligase activity and adopts the same fold as the BRcat domain.

                          10        20        30
                  ....*....|....*....|....*....|....*.
gi 767939565 2173 KRCPSCQAPIEK-NEG-CLHMTCAKCNHGFCWRCLK 2206
Cdd:cd20371     5 KPCPRCSAYIIKmNDGsCNHMTCAVCGCEFCWLCMK 40