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 198041993  332 SLCDICMCSISVFEDPVDMPCGHDFCRGCWESFLNLKIQEGEAHNIFCPAYECFQLVP 389
Cdd:cd16774     1 PLCDICMCSISVFEDPVDMPCGHEFCRACWEGYLNLKIQEGEAHNIFCPAYDCFQLVP 58

Ankyrin repeat [Signal transduction mechanisms];

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 198041993   14 NGDENLACQIYENNPQLKESL-----DPNVSYgepYQHNTPLHYAARHGMNRILgTFLFGRDGNPNKRNVHNETSMHLLC 88
Cdd:COG0666    86 GGNTLLHAAARNGDLEIVKLLleagaDVNARD---KDGETPLHLAAYNGNLEIV-KLLLEAGADVNAQDNDGNTPLHLAA 161

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 198041993   89 MGpqimisegtlhprlarpveddfRRADCLQMILrwkgaklDQGeyerAAIDAVDNKKNTPLHYAAASGMKACVELLVKH 168
Cdd:COG0666   162 AN----------------------GNLEIVKLLL-------EAG----ADVNARDNDGETPLHLAAENGHLEIVKLLLEA 208

                         170       180       190
                  ....*....|....*....|....*....|...
gi 198041993  169 GGDLFAENENKDTPCDCAEKQHHKDLALSLESQ 201
Cdd:COG0666   209 GADVNAKDNDGKTALDLAAENGNLEIVKLLLEA 241

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 198041993  332 SLCDICMCSISVFEDPVDMPCGHDFCRGCWESFLNLKIQEGEAHNIFCPAYECFQLVP 389
Cdd:cd16774     1 PLCDICMCSISVFEDPVDMPCGHEFCRACWEGYLNLKIQEGEAHNIFCPAYDCFQLVP 58

Ankyrin repeat [Signal transduction mechanisms];

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 198041993   14 NGDENLACQIYENNPQLKESL-----DPNVSYgepYQHNTPLHYAARHGMNRILgTFLFGRDGNPNKRNVHNETSMHLLC 88
Cdd:COG0666    86 GGNTLLHAAARNGDLEIVKLLleagaDVNARD---KDGETPLHLAAYNGNLEIV-KLLLEAGADVNAQDNDGNTPLHLAA 161

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 198041993   89 MGpqimisegtlhprlarpveddfRRADCLQMILrwkgaklDQGeyerAAIDAVDNKKNTPLHYAAASGMKACVELLVKH 168
Cdd:COG0666   162 AN----------------------GNLEIVKLLL-------EAG----ADVNARDNDGETPLHLAAENGHLEIVKLLLEA 208

                         170       180       190
                  ....*....|....*....|....*....|...
gi 198041993  169 GGDLFAENENKDTPCDCAEKQHHKDLALSLESQ 201
Cdd:COG0666   209 GADVNAKDNDGKTALDLAAENGNLEIVKLLLEA 241

Ariadne domain; This entry represents the Ariadne domain found in the Ariadne subfamily E3 ubiquitin ligase proteins. The C-terminal Ariadne domain adopts an elongated four-helix bundle consisting of an antiparallel arrangement of seven-to-ten-turn long helices. The Ariadne domain is straddled on one side by the IBR domain, and on the other by the RING2 domain. Notably, the Ariadne domain embraces the surface of RING2 containing the catalytic Cys357. The ariadne Domain Masks the HHARI Catalytic Cys357 and Inhibits Intrinsic E3 Activity.

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 198041993   585 EAEKKHKRFQ-ELDRFMHYYTRYKNHEHSYQLEQRLLKTAKEKmeqLSRaLKETEGGCPDTTFIEDAVHVLLKTRRILKC 663
Cdd:pfam19422    3 DREKKAERAKrDLYRYMHYHNRYKAHTDSFKLESKLKETIQEK---ISI-LEERDSKLRDFSWVTNGLYRLFRSRRVLSY 78

                           90       100       110       120       130
                   ....*....|....*....|....*....|....*....|....*....|..
gi 198041993   664 SYPYGFFL------------EPKSTKKEIFELMQTDLEMVTEDLAQKVNRPY 703
Cdd:pfam19422   79 SYPFAFYMfgdelfkdemtkEEREIKQNLFEDQQQQLEANVEKLSKFLEEPF 130

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 198041993   502 EAYEDAANCLWLLTNSK----PCANCKSPIQKNEGCN---HMQCAKCKYDFCWICLEEWkkHSSST 560
Cdd:pfam01485    1 EKYEKLLLKSYVESDPNlkwcPTPDCGYIIELTDGCSntsHVTCSKCGHEFCFNCKEEW--HEGLT 64

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

                            10        20        30        40        50        60
                    ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 198041993    502 EAYEDAANCLWLLTNSK----PCANCKSPI--QKNEGCNHMQCAKCKYDFCWICLEEWkkHSSST 560
Cdd:smart00647    1 EKYERLLLESYVESNPDlkwcPAPDCSAAIivTEEEGCNRVTCPKCGFSFCFRCKVPW--HSPVS 63

zinc finger of C3HC4-type, RING; This is a family of primate-specific Ret finger protein-like (RFPL) zinc-fingers of the C3HC4 type. Ret finger protein-like proteins are primate-specific target genes of Pax6, a key transcription factor for pancreas, eye and neocortex development. This domain is likely to be DNA-binding. This zinc-finger domain together with the RDM domain, pfam11002, forms a large zinc-finger structure of the RING/U-Box superfamily. RING-containing proteins are known to exert an E3 ubiquitin protein ligase activity with the zinc-finger structure being mandatory for binding to the E2 ubiquitin-conjugating enzyme.

                           10        20        30        40
                   ....*....|....*....|....*....|....*....|....*..
gi 198041993   334 CDICMcsiSVFEDPVDMPCGHDFCRGCWESFLnlkiQEGEAHNIFCP 380
Cdd:pfam15227    1 CPICL---DYLEKPVSIECGHSFCLSCINSLQ----KEPDGESLLCP 40

Voltage-dependent potassium channel; Provisional

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|
gi 198041993  136 RAAIDA--VDNKKNTPLHYAAASGMKACVELLVKHGGDLFAENENKDTPC-DCAEKQHHK 192
Cdd:PLN03192  546 KAKLDPdiGDSKGRTPLHIAASKGYEDCVLVLLKHACNVHIRDANGNTALwNAISAKHHK 605

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 198041993  332 SLCDICMCSISVFEDPVDMPCGHDFCRGCWESFLNLKIQEGEAHNIFCPAYECFQLVP 389
Cdd:cd16774     1 PLCDICMCSISVFEDPVDMPCGHEFCRACWEGYLNLKIQEGEAHNIFCPAYDCFQLVP 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 198041993  516 NSKPCANCKSPIQKNEGCNHMQC-AKCKYDFCWICLEEWKKHSSSTGGYYRCTRY 569
Cdd:cd22583     1 NTKPCPKCKRPIEKNQGCMHMTCsPPCKHEFCWLCLGPWSEHGERTGGFYACNRY 55

Rcat 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. 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 Rcat domain of HHARI and similar proteins that are essential for RBR E3 ligase activity and adopts the same fold as the BRcat domain.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|.
gi 198041993  512 WLLTNSKPCANCKSPIQKNEGCNHMQC--AKCKYDFCWICLEEWKKHSSStggYYRCTRYE 570
Cdd:cd20356     1 WIAANTKECPKCHVTIEKNGGCNHMVCrnQNCKYEFCWVCLGPWEPHGSS---WYNCNRYD 58

Rcat domain found in RING finger protein 14 (RNF14); RNF14, also called androgen receptor (AR)-associated protein 54 (ARA54), HFB30, or Triad2 protein, is an RBR-type E3 ubiquitin-protein ligase that is highly expressed in the testis and interacts with class III E2s (UBE2E2, UbcH6, and UBE2E3). Its differential localization may play an important role in testicular development and spermatogenesis in humans. RNF14 functions as a transcriptional regulator of mitochondrial and immune function in muscles. It is a ligand-dependent AR co-activator that enhances AR-dependent transcriptional activation. It also may participate in enhancing cell cycle progression and cell proliferation via induction of cyclin D1. Moreover, RNF14 is crucial for colon cancer cell survival. It acts as a new enhancer of the Wnt-dependent transcriptional outputs that acts at the level of the T-cell factor/lymphoid enhancer factor (TCF/LEF)-beta-catenin complex. RNF14 contains an N-terminal RWD domain, and a C-terminal RBR 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 RNF14 that is essential for RBR E3 ligase activity and adopts the same fold as the BRcat domain.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|
gi 198041993  512 WLLTNSKPCANCKSPIQKNEGCNHMQCAKCKYDFCWICLE 551
Cdd:cd20354     8 WLEKNSKPCPGCGTLIEKIDGCNKMTCTKCRTYFCWLCLK 47

Ankyrin repeat [Signal transduction mechanisms];

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 198041993   14 NGDENLACQIYENNPQLKESL-----DPNVSYgepYQHNTPLHYAARHGMNRILgTFLFGRDGNPNKRNVHNETSMHLLC 88
Cdd:COG0666    86 GGNTLLHAAARNGDLEIVKLLleagaDVNARD---KDGETPLHLAAYNGNLEIV-KLLLEAGADVNAQDNDGNTPLHLAA 161

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 198041993   89 MGpqimisegtlhprlarpveddfRRADCLQMILrwkgaklDQGeyerAAIDAVDNKKNTPLHYAAASGMKACVELLVKH 168
Cdd:COG0666   162 AN----------------------GNLEIVKLLL-------EAG----ADVNARDNDGETPLHLAAENGHLEIVKLLLEA 208

                         170       180       190
                  ....*....|....*....|....*....|...
gi 198041993  169 GGDLFAENENKDTPCDCAEKQHHKDLALSLESQ 201
Cdd:COG0666   209 GADVNAKDNDGKTALDLAAENGNLEIVKLLLEA 241

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 198041993  517 SKPCANCKSPIQKNEGCNHMQCAKCKYDFCWICLEEWKkhsSSTGGYYRCT 567
Cdd:cd20359     7 SKRCPSCQAQIEKNEGCLHMTCAKCNHGFCWRCLKPWK---PTHKDYYNCS 54

Ariadne domain; This entry represents the Ariadne domain found in the Ariadne subfamily E3 ubiquitin ligase proteins. The C-terminal Ariadne domain adopts an elongated four-helix bundle consisting of an antiparallel arrangement of seven-to-ten-turn long helices. The Ariadne domain is straddled on one side by the IBR domain, and on the other by the RING2 domain. Notably, the Ariadne domain embraces the surface of RING2 containing the catalytic Cys357. The ariadne Domain Masks the HHARI Catalytic Cys357 and Inhibits Intrinsic E3 Activity.

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 198041993   585 EAEKKHKRFQ-ELDRFMHYYTRYKNHEHSYQLEQRLLKTAKEKmeqLSRaLKETEGGCPDTTFIEDAVHVLLKTRRILKC 663
Cdd:pfam19422    3 DREKKAERAKrDLYRYMHYHNRYKAHTDSFKLESKLKETIQEK---ISI-LEERDSKLRDFSWVTNGLYRLFRSRRVLSY 78

                           90       100       110       120       130
                   ....*....|....*....|....*....|....*....|....*....|..
gi 198041993   664 SYPYGFFL------------EPKSTKKEIFELMQTDLEMVTEDLAQKVNRPY 703
Cdd:pfam19422   79 SYPFAFYMfgdelfkdemtkEEREIKQNLFEDQQQQLEANVEKLSKFLEEPF 130

Rcat domain of ATP-dependent RNA helicase DEAH12 and similar proteins; This group includes Arabidopsis thaliana ATP-dependent RNA helicases DEAH11 and DEAH12, which may be bifunctional proteins that function as DEAD-box RNA helicases (EC 3.6.4.13) and RBR-type E3 ubiquitin-protein ligases (EC 2.3.2.31). As RNA helicases, they may utilize the energy from ATP hydrolysis to unwind RNA (or DNA). DEAD-box RNA helicases participate in every aspect of RNA metabolism. As E3 ubiquitin-protein ligase, they may function as part of E3 complexes, which accept ubiquitin from specific E2 ubiquitin-conjugating enzymes and then transfer it to substrates. Other members of this group may not have an RNA helicase domain. All members 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 that is essential for RBR E3 ligase activity and adopts the same fold as the BRcat domain.

                          10        20        30
                  ....*....|....*....|....*....|....*.
gi 198041993  516 NSKPCANCKSPIQKNEGCNHMQCAKCKYDFCWICLE 551
Cdd:cd22585     1 DVKRCPKCKSLIEKIDGCNHVTCTRCGTHICWVCLK 36

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

                            10        20        30        40        50        60        70
                    ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 198041993    403 KRYLQFDIKAFVENNPAIKWCPTAGCERAVRLTKQGSNPSgsdtlsfpllrapaVDCGK-GHLFCWECLGEAHEPCDC 479
Cdd:smart00647    1 EKYERLLLESYVESNPDLKWCPAPDCSAAIIVTEEEGCNR--------------VTCPKcGFSFCFRCKVPWHSPVSC 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 198041993  518 KPCANCKSPIQKNEGCNHMQCaKCKYDFCWICLEEW 553
Cdd:cd22584     3 RRCPQCGHMVELSEGCNHMTC-RCGYEFCYLCGAPW 37

Rcat domain found in E3 ubiquitin-protein ligase ARI1 and similar proteins; This subfamily contains probable RBR-type E3 ubiquitin-protein ligases (EC 2.3.2.31) including Arabidopsis thaliana ARI1, ARI2, and ARI3. They may function as part of E3 complexes, which accept ubiquitin from E2 ubiquitin-conjugating enzymes and then transfer it to substrates. 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 ARI1-like proteins that are essential for RBR E3 ligase activity and adopt the same fold as the BRcat domain.

                          10        20        30
                  ....*....|....*....|....*....|....
gi 198041993  516 NSKPCANCKSPIQKNEGCNHMQCaKCKYDFCWIC 549
Cdd:cd22586     3 NTKLCPKCSKPVEKNGGCNLVTC-RCGQHFCWLC 35

Rcat domain found in the RING finger protein 19 (RNF19) subfamily; This subfamily includes RING finger protein RNF19A and RNF19B, which are transmembrane (TM) domain-containing RBR-type E3 ubiquitin-protein ligases. RNF19A, also called double ring-finger protein (Dorfin) or p38, localizes to the ubiquitylated inclusions in Parkinson's disease (PD), dementia with Lewy bodies (LBs), multiple system atrophy, and amyotrophic lateral sclerosis (ALS). It interacts with Psmc3, a protein component of the 19S regulatory cap of the 26S proteasome, and further participates in the ubiquitin-proteasome system in acrosome biogenesis, spermatid head shaping, and development of the head-tail coupling apparatus and tail. It modulates the ubiquitination and degradation of calcium-sensing receptor (CaR), which may contribute to a general mechanism for CaR quality control during biosynthesis. Moreover, RNF19A can also ubiquitylate mutant superoxide dismutase 1 (SOD1), the causative gene of familial ALS. It may associate with the endoplasmic reticulum-associated degradation (ERAD) pathway, which is related to the pathogenesis of neurodegenerative disorders, such as PD or Alzheimer's disease. It is also involved in the pathogenic process of PD and LB formation by ubiquitylation of synphilin-1. RNF19B, also called IBR domain-containing protein 3, or natural killer (NK) lytic-associated molecule (NKLAM), 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. 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. Both RNF19A and RNF19B contain 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 the RNF19 subfamily that is essential for RBR E3 ligase activity and adopts the same fold as the BRcat domain.

                          10        20        30
                  ....*....|....*....|....*....|....*..
gi 198041993  518 KPCANCKSPIQK-NEG-CNHMQCAKCKYDFCWICLEE 552
Cdd:cd20355     5 KPCPRCGALIIKmDDGsCNHMTCAVCGAEFCWLCMKE 41

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 198041993   502 EAYEDAANCLWLLTNSK----PCANCKSPIQKNEGCN---HMQCAKCKYDFCWICLEEWkkHSSST 560
Cdd:pfam01485    1 EKYEKLLLKSYVESDPNlkwcPTPDCGYIIELTDGCSntsHVTCSKCGHEFCFNCKEEW--HEGLT 64

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        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 198041993  417 NPAIKWCPTAGCERAVRLTKQGSNPSgsdtlsfpllrapaVDCGK-GHLFCWECLGEAHEPCDCQTW 482
Cdd:cd20335     1 NPNLRWCPTPDCGGVIRVEEPGDGPR--------------VTCPScGTSFCFKCKEEWHEGLTCEEY 53

RING finger, HC subclass, found in tripartite motif-containing protein TRIM25 and similar proteins; TRIM25, also known as estrogen-responsive finger protein (EFP), RING finger protein 147 (RNF147), or RING-type E3 ubiquitin transferase, is an E3 ubiquitin/ISG15 ligase that is induced by estrogen and is therefore particularly abundant in placenta and uterus. TRIM25 regulates various cellular processes through E3 ubiquitin ligase activity, transferring ubiquitin and ISG15 to target proteins. It mediates K63-linked polyubiquitination of retinoic acid inducible gene I (RIG-I) that is crucial for downstream antiviral interferon signaling. It is also required for melanoma differentiation-associated gene 5 (MDA5) and mitochondrial antiviral signaling (MAVS, also known as IPS-1, VISA, Cardiff) mediated activation of nuclear factor-kappaB (NF-kappaB) and interferon production. Upon UV irradiation, TRIM25 interacts with mono-ubiquitinated PCNA and promotes its ISG15 modification (ISGylation), suggesting a crucial role in termination of error-prone translesion DNA synthesis. TRIM25 also functions as a novel regulator of p53 and Mdm2. It enhances p53 and Mdm2 abundance by inhibiting their ubiquitination and degradation in 26S proteasomes. Meanwhile, it inhibits p53's transcriptional activity and dampens the response to DNA damage, and is essential for medaka development and this dependence is rescued by silencing of p53. Moreover, TRIM25 is involved in the host cellular innate immune response against retroviral infection. It interferes with the late stage of feline leukemia virus (FeLV) replication. Furthermore, TRIM25 acts as an oncogene in gastric cancer. Its blockade by RNA interference inhibits migration and invasion of gastric cancer cells through transforming growth factor-beta (TGF-beta) signaling, suggesting it presents a novel target for the detection and treatment of gastric cancer. In addition, TRIM25 acts as an RNA-specific activator for Lin28a/TuT4-mediated uridylation. TRIM25 belongs to the C-IV subclass of 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        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 198041993  334 CDICMCsisVFEDPVDMPCGHDFCRGC----WESflnlkiQEGEAHniFCPayEC 384
Cdd:cd16597     8 CSICLE---LFKDPVTLPCGHNFCGVCiektWDS------QHGSEY--SCP--QC 49

Ankyrin repeats (3 copies);

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 198041993    50 LHYAARHGMNRILgTFLFGRDGNPNKRNVHNETSMHLLCMGpqimisegtlhprlarpveddfRRADCLQMILrwkgakl 129
Cdd:pfam12796    1 LHLAAKNGNLELV-KLLLENGADANLQDKNGRTALHLAAKN----------------------GHLEIVKLLL------- 50

                           90       100       110       120
                   ....*....|....*....|....*....|....*....|....*..
gi 198041993   130 dqgeyERAAIDAVDNKKnTPLHYAAASGMKACVELLVKHGGDLFAEN 176
Cdd:pfam12796   51 -----EHADVNLKDNGR-TALHYAARSGHLEIVKLLLEKGADINVKD 91

RING finger, HC subclass, found in Arabidopsis thaliana protein ariadne homolog 6 (ARI6) and similar proteins; This subfamily includes ARI6 and ARI11. They might act as E3 ubiquitin-protein ligases, or as part of E3 complexes, which accept ubiquitin from specific E2 ubiquitin-conjugating enzymes and then transfer it to substrates. Members of this subfamily contain a typical C3HC4-type RING-HC finger.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|
gi 198041993  334 CDICMCSISVfEDPVDMPCGHDFCRGCWESFLNLKIQEGEA-HNIFCPAYECFQLVPVDV 392
Cdd:cd23141     4 CGICFESFPV-EEMRAASCGHYFCKTCWTGYIHTAISDGPGcLDLRCPDPSCPAAVGEDM 62

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 198041993  518 KPCANCKSPIQKNEGCNHMQCAKCKYDFCWICLE 551
Cdd:cd20368     7 KRCPKCKVYIERDEGCAQMMCKNCKHAFCWYCLE 40

Rcat domain found in RING finger protein 19A (RNF19A); RNF19A, also called double ring-finger protein (Dorfin), or p38, is a transmembrane (TM) domain-containing RBR-type E3 ubiquitin-protein ligase that localizes to the ubiquitylated inclusions in Parkinson's disease (PD), dementia with Lewy bodies (LBs), multiple system atrophy, and amyotrophic lateral sclerosis (ALS). It interacts with Psmc3, a protein component of the 19S regulatory cap of the 26S proteasome, and further participates in the ubiquitin-proteasome system in acrosome biogenesis, spermatid head shaping, and development of the head-tail coupling apparatus and tail. It modulates the ubiquitination and degradation of calcium-sensing receptor (CaR), which may contribute to a general mechanism for CaR quality control during biosynthesis. Moreover, RNF19A can also ubiquitylate mutant superoxide dismutase 1 (SOD1), the causative gene of familial ALS. It may associate with endoplasmic reticulum-associated degradation (ERAD) pathway, which is related to the pathogenesis of neurodegenerative disorders, such as PD or Alzheimer's disease. It is also involved in the pathogenic process of PD and LB formation by ubiquitylation of synphilin-1. RNF19A 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 RNF19A that is essential for RBR E3 ligase activity and adopts the same fold as the BRcat domain.

                          10        20        30
                  ....*....|....*....|....*....|....*..
gi 198041993  518 KPCANCKSPIQK-NEG-CNHMQCAKCKYDFCWICLEE 552
Cdd:cd20370    10 KPCPRCAAYIIKmNDGsCNHMTCAVCGCEFCWLCMKE 46

Ankyrin repeats (many copies);

                           10        20        30        40
                   ....*....|....*....|....*....|....*....|....*....
gi 198041993   147 NTPLHYAAASGMKACVELLVKHGGDLFAENENKDTPCDCAEKQHHKDLA 195
Cdd:pfam13637    2 LTALHAAAASGHLELLRLLLEKGADINAVDGNGETALHFAASNGNVEVL 50

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

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*..
gi 198041993  334 CDICMcsiSVFEDPVDMPCGHDFCRGCWESFLnlkiqegEAHNIFCP 380
Cdd:cd16449     3 CPICL---ERLKDPVLLPCGHVFCRECIRRLL-------ESGSIKCP 39

ankyrin repeats; Ankyrin repeats are about 33 amino acids long and occur in at least four consecutive copies. They are involved in protein-protein interactions. The core of the repeat seems to be an helix-loop-helix structure.

                            10        20
                    ....*....|....*....|....*...
gi 198041993    147 NTPLHYAAASGMKACVELLVKHGGDLFA 174
Cdd:smart00248    3 RTPLHLAAENGNLEVVKLLLDKGADINA 30

RING finger, HC subclass, found in tripartite motif-containing protein 59 (TRIM59) and similar proteins; TRIM59, also known as RING finger protein 104 (RNF104) or tumor suppressor TSBF-1, is a putative E3 ubiquitin-protein ligase that functions as a novel multiple cancer biomarker for immunohistochemical detection of early tumorigenesis. It is upregulated in gastric cancer and promotes gastric carcinogenesis by interacting with and targeting the P53 tumor suppressor for its ubiquitination and degradation. It also acts as a novel accessory molecule involved in cytotoxicity of BCG-activated macrophages (BAM). Moreover, TRIM59 may serve as a multifunctional regulator for innate immune signaling pathways. It interacts with ECSIT and negatively regulates nuclear factor-kappaB (NF- kappa B) and interferon regulatory factor (IRF)-3/7-mediated signal pathways. TRIM59 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. In addition, TRIM59 contains a C-terminal transmembrane domain.

                          10        20        30
                  ....*....|....*....|....*....|....
gi 198041993  334 CDICMcsiSVFEDPVDMPCGHDFCRGCWESFLNL 367
Cdd:cd16763     6 CSVCY---SLFEDPRVLPCSHTFCRNCLENILQV 36

RING finger, HC subclass, found in tripartite motif-containing protein 62 (TRIM62) and similar proteins; TRIM62, also known as Ductal Epithelium Associated Ring Chromosome 1 (DEAR1), is a cytoplasmic E3 ubiquitin-protein ligase that was identified as a dominant regulator of acinar morphogenesis in the mammary gland. It is implicated in the inflammatory response of immune cells by regulating the Toll-like receptor 4 (TLR4) signaling pathway, leading to increased activity of the activator protein 1 (AP-1) transcription factor in primary macrophages. It is also involved in muscular protein homeostasis, especially during inflammation-induced atrophy, and may play a role in the pathogenesis of ICU-acquired weakness (ICUAW) by activating and maintaining inflammation in myocytes. Moreover, TRIM62 facilitates K27-linked poly-ubiquitination of CARD9 and also regulates CARD9-mediated anti-fungal immunity and intestinal inflammation. It also functions as a chromosome 1p35 tumor suppressor and negatively regulates transforming growth factor beta (TGFbeta)-driven epithelial-mesenchymal transition (EMT) by binding to and promoting the ubiquitination of SMAD3, a major effector of TGFbeta-mediated EMT. TRIM62 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
                  ....*....|....*....|....*....|.
gi 198041993  330 DTSLCDICMcsiSVFEDPVDMPCGHDFCRGC 360
Cdd:cd16608     5 DELLCSICL---SIYQDPVSLGCEHYFCRQC 32

Ankyrin repeat; Ankyrins are multifunctional adaptors that link specific proteins to the membrane-associated, spectrin- actin cytoskeleton. This repeat-domain is a 'membrane-binding' domain of up to 24 repeated units, and it mediates most of the protein's binding activities. Repeats 13-24 are especially active, with known sites of interaction for the Na/K ATPase, Cl/HCO(3) anion exchanger, voltage-gated sodium channel, clathrin heavy chain and L1 family cell adhesion molecules. The ANK repeats are found to form a contiguous spiral stack such that ion transporters like the anion exchanger associate in a large central cavity formed by the ANK repeat spiral, while clathrin and cell adhesion molecules associate with specific regions outside this cavity.

                           10        20        30
                   ....*....|....*....|....*....|..
gi 198041993   147 NTPLHYAAAS-GMKACVELLVKHGGDLFAENE 177
Cdd:pfam00023    3 NTPLHLAAGRrGNLEIVKLLLSKGADVNARDK 34

Rcat domain found in heme-oxidized IRP2 ubiquitin ligase 1 (HOIL-1) and similar proteins; HOIL-1 is also called RBCK1, HOIL-1L, RanBP-type and C3HC4-type zinc finger-containing protein 1, HBV-associated factor 4, Hepatitis B virus X-associated protein 4, RING finger protein 54 (RNF54), ubiquitin-conjugating enzyme 7-interacting protein 3, or UbcM4-interacting protein 28 (UIP28). Together with the E3 ubiquitin-protein ligase RNF31 (also known as HOIP) and SHANK-associated RH domain interacting protein (SHARPIN), it forms the E3-ligase complex (also known as linear-ubiquitin-chain assembly complex LUBAC) that regulates NF-kappaB activity and apoptosis through conjugation of linear polyubiquitin chains to NF-kappaB essential modulator (also known as NEMO or IKBKG). HOIL-1 plays a crucial role in TNF-alpha-mediated NF-kappaB activation. It also functions as an ubiquitin-protein ligase E3 that interacts with not only PKCbeta but also PKCzeta. It can recognize heme-oxidized IRP2 (iron regulatory protein2) and is thought to affect the turnover of oxidatively damaged proteins. HOIL-1 contains an N-terminal ubiqutin-like (UBL) domain and an Npl4 zinc-finger (NZF) domain, which regulate the interaction with the LUBAC subunit RNF31 and ubiquitin, respectively. The NZF domain belongs to RanBP2-type zinc finger (zf-RanBP2) domain superfamily. In addition, HOIL-1 has 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 HOIL1 that is essential for RBR E3 ligase activity and adopts the same fold as the BRcat domain.

                          10        20
                  ....*....|....*....|....*....
gi 198041993  520 CANCKSPIQKNEGCNHMQCAKCKYDFCWI 548
Cdd:cd20358    10 CPQCQVIVQKKDGCDWIRCSMCKTEICWV 38

RING finger, HC subclass, found in tripartite motif-containing proteins, TRIM7, TRIM11 and TRIM27, and similar proteins; TRIM7, TRIM11 and TRIM27, closely related tripartite motif-containing proteins, belong 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, Bbox2, and a coiled coil region, as well as a SPRY/B30.2 domain positioned C-terminal to the RBCC domain. TRIM7, also known as glycogenin-interacting protein (GNIP) or RING finger protein 90 (RNF90), is an E3 ubiquitin-protein ligase that mediates c-Jun/AP-1 activation by Ras signalling. Its phosphorylation and activation by MSK1 in response to direct activation by the Ras-Raf-MEK-ERK pathway can stimulate TRIM7 E3 ubiquitin ligase activity in mediating Lys63-linked ubiquitination of the AP-1 coactivator RACO-1, leading to RACO-1 protein stabilization. Moreover, TRIM7 binds and activates glycogenin, the self-glucosylating initiator of glycogen biosynthesis. TRIM11, also known as protein BIA1, or RING finger protein 92 (RNF92), is an E3 ubiquitin-protein ligase involved in the development of the central nervous system. It is overexpressed in high-grade gliomas and promotes proliferation, invasion, migration and glial tumor growth. TRIM11 acts as a potential therapeutic target for congenital central hypoventilation syndrome (CCHS) by mediating the degradation of CCHS-associated polyalanine-expanded Phox2b. TRIM11 modulates the function of neurogenic transcription factor Pax6 through the ubiquitin-proteosome system, and thus plays an essential role for Pax6-dependent neurogenesis. It also binds to and destabilizes a key component of the activator-mediated cofactor complex (ARC105), humanin, a neuroprotective peptide against Alzheimer's disease-relevant insults, and further regulates ARC105 function in transforming growth factor beta (TGFbeta) signaling. Moreover, TRIM11 negatively regulates retinoic acid-inducible gene-I (RIG-I)-mediated interferon-beta (IFNbeta) production and antiviral activity by targeting TANK-binding kinase-1 (TBK1). It may contribute to the endogenous restriction of retroviruses in cells. It enhances N-tropic murine leukemia virus (N-MLV) entry by interfering with Ref1 restriction. It also suppresses the early steps of human immunodeficiency virus HIV-1 transduction, resulting in decreased reverse transcripts. TRIM27, also known as RING finger protein 76 (RNF76), RET finger protein (RFP), or zinc finger protein RFP, is a nuclear E3 ubiquitin-protein ligase that is highly expressed in testis and in various tumor cell lines. Expression of TRIM27 is associated with prognosis of colon and endometrial cancers. TRIM27 was first identified as a fusion partner of the RET receptor tyrosine kinase. It functions as a transcriptional repressor and associates with several proteins involved in transcriptional activity, such as enhancer of polycomb 1 (Epc1), a member of the Polycomb group proteins, and Mi-2beta, a main component of the nucleosome remodeling and deacetylase (NuRD) complex, and the cell cycle regulator retinoblastoma protein (RB1). It also interacts with HDAC1, leading to downregulation of thioredoxin binding protein 2 (TBP-2), which inhibits the function of thioredoxin. Moreover, TRIM27 mediates Pax7-induced ubiquitination of MyoD in skeletal muscle atrophy. In addition, it inhibits muscle differentiation by modulating serum response factor (SRF) and Epc1. TRIM27 promotes a non-canonical polyubiquitination of PTEN, a lipid phosphatase that catalyzes PtdIns(3,4,5)P3 (PIP3) to PtdIns(4,5)P2 (PIP2). It is an IKKepsilon-interacting protein that regulates IkappaB kinase (IKK) function and negatively regulates signaling involved in the antiviral response and inflammation. TRIM27 also forms a protein complex with MBD4 or MBD2 or MBD3, and thus plays an important role in the enhancement of transcriptional repression through MBD proteins in tumorigenesis, spermatogenesis, and embryogenesis. It is a component of an estrogen receptor 1 (ESR1) regulatory complex that is involved in estrogen receptor-mediated transcription in MCF-7 cells.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|
gi 198041993  334 CDICMcsiSVFEDPVDMPCGHDFCRG----CWEsflnlkiqEGEAhNIFCPayECFQLVP 389
Cdd:cd16594     8 CPICL---DYFTDPVTLDCGHSFCRAciarCWE--------EPET-SASCP--QCRETCP 53

RING finger, HC subclass, found in tripartite motif-containing protein 77 (TRIM77) and similar proteins; TRIM77 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 two consecutive zinc-binding domains, a C3HC4-type RING-HC finger and Bbox2, as well as a SPRY/B30.2 domain positioned C-terminal to the RBCC domain.

                          10        20
                  ....*....|....*....|....*...
gi 198041993  335 DICMCSI--SVFEDPVDMPCGHDFCRGC 360
Cdd:cd16543     2 DQLTCSIclDLLKDPVTIPCGHSFCMNC 29

RING finger, HC subclass, found in the family of RING finger proteins RNF19A, RNF19B and similar proteins; The family includes RING finger protein RNF19A and RNF19B, both of which are transmembrane (TM) domain-containing RBR-type E3 ubiquitin-protein ligases. RNF19A, also known as double ring-finger protein (Dorfin) or p38, localizes to the ubiquitylated inclusions in Parkinson's disease (PD), dementia with Lewy bodies, multiple system atrophy, and amyotrophic lateral sclerosis (ALS). It interacts with Psmc3, a protein component of the 19S regulatory cap of the 26S proteasome, and further participates in the ubiquitin-proteasome system in acrosome biogenesis, spermatid head shaping, and development of the head-tail coupling apparatus and tail. It modulates the ubiquitination and degradation of calcium-sensing receptor (CaR), which may contribute to a general mechanism for CaR quality control during biosynthesis. Moreover, RNF19A can also ubiquitylate mutant superoxide dismutase 1 (SOD1), the causative gene of familial ALS. It may associate with endoplasmic reticulum-associated degradation (ERAD) pathway, which is related to the pathogenesis of neurodegenerative disorders, such as PD or Alzheimer's disease. RNF19B, also known as IBR domain-containing protein 3 or natural killer lytic-associated molecule (NKLAM), plays a role in controlling tumor dissemination and metastasis. It is involved in the cytolytic function of natural killer (NK) cells and cytotoxic T lymphocytes (CTLs). It interacts with ubiquitin conjugates UbcH7 and UbcH8, and ubiquitinates uridine kinase like-1 (URKL-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. Both RNF19A and RNF19B contain 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 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 198041993  334 CDICMCSISVFEDPVDMPCGHDFCRGCWESFLNLKIQEGEAhNIFCPayEC 384
Cdd:cd16629     3 CPLCLDDLSPEFFPILLSCEHRSCRDCLRQYLTIEISESRV-NISCP--EC 50

RING finger, HC subclass, found in tripartite motif-containing protein TRIM4 and similar proteins; TRIM4 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, Bbox2, and a coiled coil region, as well as a SPRY/B30.2 domain positioned C-terminal to the RBCC domain. TRIM4, also known as RING finger protein 87 (RNF87), is a cytoplasmic E3 ubiquitin-protein ligase that has recently evolved and is present only in higher mammals. It transiently interacts with mitochondria, induces mitochondrial aggregation and sensitizes the cells to hydrogen peroxide (H2O2) induced death. Its interaction with peroxiredoxin 1 (PRX1) is critical for the regulation of H2O2 induced cell death. Moreover, TRIM4 functions as a positive regulator of RIG-I-mediated type I interferon induction. It regulates the K63-linked ubiquitination of RIG-1 and assembly of antiviral signaling complex at the mitochondria.

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gi 198041993  334 CDICMcsiSVFEDPVDMPCGHDFCRGC 360
Cdd:cd16590     9 CPICL---DYFQDPVSIECGHNFCRGC 32

RING finger, HC subclass, found in tripartite motif-containing protein 13 (TRIM13) and similar proteins; TRIM13, also known as B-cell chronic lymphocytic leukemia tumor suppressor Leu5, leukemia-associated protein 5, putative tumor suppressor RFP2, RING finger protein 77 (RNF77), or Ret finger protein 2, is an endoplasmic reticulum (ER) membrane anchored E3 ubiquitin-protein ligase that interacts with proteins localized to the ER, including valosin-containing protein (VCP), a protein indispensable for ER-associated degradation (ERAD). It also targets the known ER proteolytic substrate CD3-delta, but not the N-end rule substrate Ub-R-YFP (yellow fluorescent protein) for degradation. Moreover, TRIM13 regulates ubiquitination and degradation of NEMO to suppress tumor necrosis factor (TNF) induced nuclear factor-kappaB (NF- kappa B) activation. It is also involved in NF-kappaB p65 activation and nuclear factor of activated T-cells (NFAT)-dependent activation of c-Rel upon T-cell receptor engagement. Furthermore, TRIM13 negatively regulates melanoma differentiation-associated gene 5 (MDA5)-mediated type I interferon production. It also regulates caspase-8 ubiquitination, translocation to autophagosomes, and activation during ER stress induced cell death. Meanwhile, TRIM13 enhances ionizing radiation-induced apoptosis by increasing p53 stability and decreasing AKT kinase activity through MDM2 and AKT degradation. TRIM13 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. In addition, TRIM13 contains a C-terminal transmembrane domain.

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gi 198041993  334 CDICMCsisVFEDPVDMPCGHDFCRGCWESFL 365
Cdd:cd16762     6 CPICCC---LFDDPRVLPCSHNFCKKCLEGIL 34

Modified RING finger, HC subclass (C3HC3D-type), found in tumor necrosis factor (TNF) receptor-associated factor 7 (TRAF7) and similar proteins; TRAF7, also known as RING finger and WD repeat-containing protein 1 or RING finger protein 119 (RNF119), is an E3 ubiquitin-protein ligase involved in signal transduction pathways that lead either to activation or repression of NF-kappaB transcription factor by promoting K29-linked ubiquitination of several cellular targets, including the NF-kappaB essential modulator (NEMO) and the p65 subunit of NF-kappaB transcription factor. It is also involved in K29-linked polyubiquitination that has been implicated in lysosomal degradation of proteins. Moreover, TRAF7 is required for K48-linked ubiquitination of p53, a key tumor suppressor and a master regulator of various signaling pathways, such as those related to apoptosis, cell cycle and DNA repair. It is also required for tumor necrosis factor alpha (TNFalpha)-induced Jun N-terminal kinase activation and promotes cell death by regulating polyubiquitination and lysosomal degradation of c-FLIP protein. Furthermore, TRAF7 functions as small ubiquitin-like modifier (SUMO) E3 ligase involved in other post-translational modification, such as sumoylation. It binds to and stimulates sumoylation of the proto-oncogene product c-Myb, a transcription factor regulating proliferation and differentiation of hematopoietic cells. It potentiates MEKK3-induced AP1 and CHOP activation and induces apoptosis. Meanwhile, TRAF7 mediates MyoD1 regulation of the pathway and cell-cycle progression in myoblasts. It also plays a role in Toll-like receptors (TLR) signaling. TRAF7 contains an N-terminal domain with a modified C3HC3D-type RING-HC finger and an adjacent zinc finger, and a unique C-terminal domain that comprises a coiled coil domain and seven WD40 repeats.

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gi 198041993  334 CDICMcsiSVFEDPVDMPCGHDFCRGCWESFLNLK 368
Cdd:cd16644     8 CPLCQ---RVFKDPVITSCGHTFCRRCALTAPGEK 39