RING finger, HC subclass, found in apoptosis protein c-IAP1, c-IAP2, livin, and similar proteins; The cellular inhibitor of apoptosis protein c-IAPs function as ubiquitin E3 ligases that mediate the ubiquitination of substrates involved in apoptosis, nuclear factor-kappaB (NF-kappaB) signaling, and oncogenesis. Unlike other IAPs, such as XIAP, c-IAPs exhibit minimal binding to caspases and may not play an important role in the inhibition of these proteases. c-IAP1, also known as baculoviral IAP repeat-containing protein BIRC2, IAP-2, RING finger protein 48, or TNFR2-TRAF-signaling complex protein 2, is a potent regulator of the tumor necrosis factor (TNF) receptor family and NF-kappaB signaling pathways in the cytoplasm. It can also regulate E2F1 transcription factor-mediated control of cyclin transcription in the nucleus. c-IAP2, also known as BIRC3, IAP-1, apoptosis inhibitor 2 (API2), or IAP homolog C, also influences ubiquitin-dependent pathways that modulate innate immune signalling by activation of NF-kappaB. c-IAPs contain three N-terminal baculoviral IAP repeat (BIR) domains that enable interactions with proteins, a ubiquitin-association (UBA) domain that is responsible for the binding of polyubiquitin (polyUb), a caspase activation and recruitment domain (CARD) that serves as a protein interaction surface, and a C3HC4-type RING-HC finger at the carboxyl terminus that is required for ubiquitin ligase activity. Livin, also known as baculoviral IAP repeat-containing protein 7 (BIRC7), kidney inhibitor of apoptosis protein (KIAP), melanoma inhibitor of apoptosis protein (ML-IAP), or RING finger protein 50, was identified as the melanoma IAP. It plays crucial roles in apoptosis, cell proliferation, and cell cycle control. Its anti-apoptotic activity is regulated by the inhibition of caspase-3, -7, and -9. Its E3 ubiquitin-ligase-like activity promotes degradation of Smac/DIABLO, a critical endogenous regulator of all IAPs. Unlike other family members, mammalian livin contains a single BIR domain and a C3HC4-type RING-HC finger. The UBA domain can be detected in non-mammalian homologs of livin.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*..
gi 564362256 546 LRKLQEERTCKVCMDREVSLVFIPCGHLVVCKECAPSLRKCPICRGTIKGTVRTFLS 602
Cdd:cd16713    1 LRRLQEERTCKVCMDKEVSIVFIPCGHLVVCTECAPSLRKCPICRATIKGTVRTFLS 57

Baculoviral inhibition of apoptosis protein repeat domain; Found in inhibitors of apoptosis proteins (IAPs) and other proteins. In higher eukaryotes, BIR domains inhibit apoptosis by acting as direct inhibitors of the caspase family of protease enzymes. In yeast, BIR domains are involved in regulating cytokinesis. This novel fold is stabilized by zinc tetrahedrally coordinated by one histidine and three cysteine residues and resembles a classical zinc finger.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 564362256 170 KARLLTYQTWPLS-FLSPAELAKAGFYYTGPGDRVACFACGGKLSNWDRKDDPLSEHRRHFPSCPFLK 236
Cdd:cd00022    1 EARLKTFKNWPISlKVTPEKLAEAGFYYTGRGDEVKCFFCGLELKNWEPGDDPWEEHKRWSPNCPFVL 68

UBA domain found in baculoviral IAP repeat-containing protein BIRC2, BIRC3 and similar proteins; The subfamily includes cellular inhibitor of apoptosis protein 1 (c-IAP1) and c-IAP2. c-IAPs function as ubiquitin E3 ligases that mediate the ubiquitination of the substrates involved in apoptosis, nuclear factor-kappaB (NF-kappaB)signaling, and oncogenesis. Unlike other apoptosis proteins (IAPs), such as XIAP, c-IAPs exhibit minimal binding to caspases and may not play an important role in the inhibition of these proteases. c-IAP1, also called baculoviral IAP repeat-containing protein BIRC2, IAP-2, RING finger protein 48, or TNFR2-TRAF-signaling complex protein 2, is a potent regulator of the tumor necrosis factor (TNF) receptor family and NF-kappaB signaling pathways in the cytoplasm. It can also regulate E2F1 transcription factor-mediated control of cyclin transcription in the nucleus. c-IAP2, also called BIRC3, IAP-1, apoptosis inhibitor 2 (API2), or IAP homolog C, also influences ubiquitin-dependent pathways that modulate innate immune signalling by activation of NF-kappaB. c-IAPs contain three N-terminal baculoviral IAP repeat (BIR) domains that enable interactions with proteins, a ubiquitin-association (UBA) domain that is responsible for the binding of binds polyubiquitin (polyUb), a caspase activation and recruitment domain (CARD) that serves as a protein interaction surface, and a RING domain at the carboxyl terminus that is required for ubiquitin ligase activity.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|
gi 564362256 376 MNTPVVKAALDMGFSRSLVRQTVQRQILATGENYRTVSDLVIGLLDAEDE 425
Cdd:cd14394    1 MNTPVVKSALEMGFNRRLVKQTVQSKILTSGENYKTVNDLVSDLLSAEDE 50

RING finger, HC subclass, found in apoptosis protein c-IAP1, c-IAP2, livin, and similar proteins; The cellular inhibitor of apoptosis protein c-IAPs function as ubiquitin E3 ligases that mediate the ubiquitination of substrates involved in apoptosis, nuclear factor-kappaB (NF-kappaB) signaling, and oncogenesis. Unlike other IAPs, such as XIAP, c-IAPs exhibit minimal binding to caspases and may not play an important role in the inhibition of these proteases. c-IAP1, also known as baculoviral IAP repeat-containing protein BIRC2, IAP-2, RING finger protein 48, or TNFR2-TRAF-signaling complex protein 2, is a potent regulator of the tumor necrosis factor (TNF) receptor family and NF-kappaB signaling pathways in the cytoplasm. It can also regulate E2F1 transcription factor-mediated control of cyclin transcription in the nucleus. c-IAP2, also known as BIRC3, IAP-1, apoptosis inhibitor 2 (API2), or IAP homolog C, also influences ubiquitin-dependent pathways that modulate innate immune signalling by activation of NF-kappaB. c-IAPs contain three N-terminal baculoviral IAP repeat (BIR) domains that enable interactions with proteins, a ubiquitin-association (UBA) domain that is responsible for the binding of polyubiquitin (polyUb), a caspase activation and recruitment domain (CARD) that serves as a protein interaction surface, and a C3HC4-type RING-HC finger at the carboxyl terminus that is required for ubiquitin ligase activity. Livin, also known as baculoviral IAP repeat-containing protein 7 (BIRC7), kidney inhibitor of apoptosis protein (KIAP), melanoma inhibitor of apoptosis protein (ML-IAP), or RING finger protein 50, was identified as the melanoma IAP. It plays crucial roles in apoptosis, cell proliferation, and cell cycle control. Its anti-apoptotic activity is regulated by the inhibition of caspase-3, -7, and -9. Its E3 ubiquitin-ligase-like activity promotes degradation of Smac/DIABLO, a critical endogenous regulator of all IAPs. Unlike other family members, mammalian livin contains a single BIR domain and a C3HC4-type RING-HC finger. The UBA domain can be detected in non-mammalian homologs of livin.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*..
gi 564362256 546 LRKLQEERTCKVCMDREVSLVFIPCGHLVVCKECAPSLRKCPICRGTIKGTVRTFLS 602
Cdd:cd16713    1 LRRLQEERTCKVCMDKEVSIVFIPCGHLVVCTECAPSLRKCPICRATIKGTVRTFLS 57

Baculoviral inhibition of apoptosis protein repeat domain; Found in inhibitors of apoptosis proteins (IAPs) and other proteins. In higher eukaryotes, BIR domains inhibit apoptosis by acting as direct inhibitors of the caspase family of protease enzymes. In yeast, BIR domains are involved in regulating cytokinesis. This novel fold is stabilized by zinc tetrahedrally coordinated by one histidine and three cysteine residues and resembles a classical zinc finger.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 564362256 256 AARVRTFSTWPSSALVHPQELASAGFYYTGHSDDVKCFCCDGGLRCWESGDDPWVEHAKWFPRCEYL 322
Cdd:cd00022    1 EARLKTFKNWPISLKVTPEKLAEAGFYYTGRGDEVKCFFCGLELKNWEPGDDPWEEHKRWSPNCPFV 67

Baculoviral inhibition of apoptosis protein repeat; Domain found in inhibitor of apoptosis proteins (IAPs) and other proteins. Acts as a direct inhibitor of caspase enzymes.

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 564362256   168 TEKARLLTYQTWP-LSFLSPAELAKAGFYYTGPGDRVACFACGGKLSNWDRKDDPLSEHRRHFPSCPFLK 236
Cdd:smart00238   1 SEEARLKTFQNWPyNSKCTPEQLAEAGFYYTGVGDEVKCFFCGGELDNWEPGDDPWEEHKKWSPNCPFVR 70

Inhibitor of Apoptosis domain; BIR stands for 'Baculovirus Inhibitor of apoptosis protein Repeat'. It is found repeated in inhibitor of apoptosis proteins (IAPs), and in fact it is also known as IAP repeat. These domains characteriztically have a number of invariant residues, including 3 conserved cysteines and one conserved histidine that coordinate a zinc ion. They are usually made up of 4-5 alpha helices and a three-stranded beta-sheet. BIR is also found in other proteins known as BIR-domain-containing proteins (BIRPs), such as Survivin.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 564362256  172 RLLTYQTWPLSFL---SPAELAKAGFYYTGPGDRVACFACGGKLSNWDRKDDPLSEHRRHFPSCPFLK 236
Cdd:pfam00653   1 RLATFENWPHSNKsppTPEELAEAGFYYTGTGDRVQCFYCGLELDGWEEGDDPWEEHKKHSPDCPFLK 68

Baculoviral inhibition of apoptosis protein repeat domain; Found in inhibitors of apoptosis proteins (IAPs) and other proteins. In higher eukaryotes, BIR domains inhibit apoptosis by acting as direct inhibitors of the caspase family of protease enzymes. In yeast, BIR domains are involved in regulating cytokinesis. This novel fold is stabilized by zinc tetrahedrally coordinated by one histidine and three cysteine residues and resembles a classical zinc finger.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 564362256  32 RLSTYSTFPAGVPVSERSLARAGFYYTGVNDKVKCFSCGLMLDNWKQGDSPIEKHRKLYPSCSFVQ 97
Cdd:cd00022    3 RLKTFKNWPISLKVTPEKLAEAGFYYTGRGDEVKCFFCGLELKNWEPGDDPWEEHKRWSPNCPFVL 68

Caspase recruitment domain; Motif contained in proteins involved in apoptotic signaling. Predicted to possess a DEATH (pfam00531) domain-like fold.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 564362256  445 LIRKNKMVLLQHLTPVTPILDCLLSARVITEQEYDAVKQKPHTL-QARTLIDTVLAKGNTAATSFRNSLQEIDPGLYRDI 523
Cdd:pfam00619   3 LLKKNRVALVERLGTLDGLLDYLLEKNVLTEEEEEKIKANPTRLdKARELLDLVLKKGPKACQIFLEALKEGDPDLASDL 82

                  .
gi 564362256  524 F 524
Cdd:pfam00619  83 E 83

Zinc finger, C3HC4 type (RING finger);

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 564362256  551 EERTCKVCMDREVSLVFIPCGHLVVCKECAPSLR----KCPICRGTIKGT 596
Cdd:pfam13920   1 EDLLCVICLDRPRNVVLLPCGHLCLCEECAERLLrkkkKCPICRQPIESV 50

Ring finger; E3 ubiquitin-protein ligase activity is intrinsic to the RING domain of c-Cbl and is likely to be a general function of this domain; Various RING fingers exhibit binding activity towards E2 ubiquitin-conjugating enzymes (Ubc' s)

                           10        20        30        40
                   ....*....|....*....|....*....|....*....|.
gi 564362256   555 CKVCMDR-EVSLVFIPCGHlVVCKECAPSL-----RKCPIC 589
Cdd:smart00184   1 CPICLEEyLKDPVILPCGH-TFCRSCIRKWlesgnNTCPIC 40

RING finger, HC subclass, found in apoptosis protein c-IAP1, c-IAP2, livin, and similar proteins; The cellular inhibitor of apoptosis protein c-IAPs function as ubiquitin E3 ligases that mediate the ubiquitination of substrates involved in apoptosis, nuclear factor-kappaB (NF-kappaB) signaling, and oncogenesis. Unlike other IAPs, such as XIAP, c-IAPs exhibit minimal binding to caspases and may not play an important role in the inhibition of these proteases. c-IAP1, also known as baculoviral IAP repeat-containing protein BIRC2, IAP-2, RING finger protein 48, or TNFR2-TRAF-signaling complex protein 2, is a potent regulator of the tumor necrosis factor (TNF) receptor family and NF-kappaB signaling pathways in the cytoplasm. It can also regulate E2F1 transcription factor-mediated control of cyclin transcription in the nucleus. c-IAP2, also known as BIRC3, IAP-1, apoptosis inhibitor 2 (API2), or IAP homolog C, also influences ubiquitin-dependent pathways that modulate innate immune signalling by activation of NF-kappaB. c-IAPs contain three N-terminal baculoviral IAP repeat (BIR) domains that enable interactions with proteins, a ubiquitin-association (UBA) domain that is responsible for the binding of polyubiquitin (polyUb), a caspase activation and recruitment domain (CARD) that serves as a protein interaction surface, and a C3HC4-type RING-HC finger at the carboxyl terminus that is required for ubiquitin ligase activity. Livin, also known as baculoviral IAP repeat-containing protein 7 (BIRC7), kidney inhibitor of apoptosis protein (KIAP), melanoma inhibitor of apoptosis protein (ML-IAP), or RING finger protein 50, was identified as the melanoma IAP. It plays crucial roles in apoptosis, cell proliferation, and cell cycle control. Its anti-apoptotic activity is regulated by the inhibition of caspase-3, -7, and -9. Its E3 ubiquitin-ligase-like activity promotes degradation of Smac/DIABLO, a critical endogenous regulator of all IAPs. Unlike other family members, mammalian livin contains a single BIR domain and a C3HC4-type RING-HC finger. The UBA domain can be detected in non-mammalian homologs of livin.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*..
gi 564362256 546 LRKLQEERTCKVCMDREVSLVFIPCGHLVVCKECAPSLRKCPICRGTIKGTVRTFLS 602
Cdd:cd16713    1 LRRLQEERTCKVCMDKEVSIVFIPCGHLVVCTECAPSLRKCPICRATIKGTVRTFLS 57

Baculoviral inhibition of apoptosis protein repeat domain; Found in inhibitors of apoptosis proteins (IAPs) and other proteins. In higher eukaryotes, BIR domains inhibit apoptosis by acting as direct inhibitors of the caspase family of protease enzymes. In yeast, BIR domains are involved in regulating cytokinesis. This novel fold is stabilized by zinc tetrahedrally coordinated by one histidine and three cysteine residues and resembles a classical zinc finger.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 564362256 256 AARVRTFSTWPSSALVHPQELASAGFYYTGHSDDVKCFCCDGGLRCWESGDDPWVEHAKWFPRCEYL 322
Cdd:cd00022    1 EARLKTFKNWPISLKVTPEKLAEAGFYYTGRGDEVKCFFCGLELKNWEPGDDPWEEHKRWSPNCPFV 67

Baculoviral inhibition of apoptosis protein repeat; Domain found in inhibitor of apoptosis proteins (IAPs) and other proteins. Acts as a direct inhibitor of caspase enzymes.

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 564362256   168 TEKARLLTYQTWP-LSFLSPAELAKAGFYYTGPGDRVACFACGGKLSNWDRKDDPLSEHRRHFPSCPFLK 236
Cdd:smart00238   1 SEEARLKTFQNWPyNSKCTPEQLAEAGFYYTGVGDEVKCFFCGGELDNWEPGDDPWEEHKKWSPNCPFVR 70

Inhibitor of Apoptosis domain; BIR stands for 'Baculovirus Inhibitor of apoptosis protein Repeat'. It is found repeated in inhibitor of apoptosis proteins (IAPs), and in fact it is also known as IAP repeat. These domains characteriztically have a number of invariant residues, including 3 conserved cysteines and one conserved histidine that coordinate a zinc ion. They are usually made up of 4-5 alpha helices and a three-stranded beta-sheet. BIR is also found in other proteins known as BIR-domain-containing proteins (BIRPs), such as Survivin.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 564362256  172 RLLTYQTWPLSFL---SPAELAKAGFYYTGPGDRVACFACGGKLSNWDRKDDPLSEHRRHFPSCPFLK 236
Cdd:pfam00653   1 RLATFENWPHSNKsppTPEELAEAGFYYTGTGDRVQCFYCGLELDGWEEGDDPWEEHKKHSPDCPFLK 68

Baculoviral inhibition of apoptosis protein repeat domain; Found in inhibitors of apoptosis proteins (IAPs) and other proteins. In higher eukaryotes, BIR domains inhibit apoptosis by acting as direct inhibitors of the caspase family of protease enzymes. In yeast, BIR domains are involved in regulating cytokinesis. This novel fold is stabilized by zinc tetrahedrally coordinated by one histidine and three cysteine residues and resembles a classical zinc finger.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 564362256  32 RLSTYSTFPAGVPVSERSLARAGFYYTGVNDKVKCFSCGLMLDNWKQGDSPIEKHRKLYPSCSFVQ 97
Cdd:cd00022    3 RLKTFKNWPISLKVTPEKLAEAGFYYTGRGDEVKCFFCGLELKNWEPGDDPWEEHKRWSPNCPFVL 68

RING finger, HC subclass, found in E3 ubiquitin-protein ligase XIAP, baculoviral IAP repeat-containing protein 8 (BIRC8) and similar proteins; XIAP, also known as baculoviral IAP repeat-containing protein 4 (BIRC4), IAP-like protein (ILP), inhibitor of apoptosis protein 3 (IAP-3), or X-linked inhibitor of apoptosis protein (X-linked IAP), is a potent suppressor of apoptosis that directly inhibits specific members of the caspase family of cysteine proteases, including caspase-3, -7, and -9. It promotes proteasomal degradation of caspase-3 and enhances its anti-apoptotic effect in Fas-induced cell death. The ubiquitin-protein ligase (E3) activity of XIAP also exhibits in the ubiquitination of second mitochondria-derived activator of caspases (Smac). The mitochondrial proteins, Smac/DIABLO and Omi/HtrA2, can inhibit the antiapoptotic activity of XIAP. XIAP has also been implicated in several intracellular signaling cascades involved in the cellular response to stress, such as the c-Jun N-terminal kinase (JNK), the nuclear factor-kappaB (NF-kappaB), and the transforming growth factor-beta (TGF-beta) pathways. Moreover, XIAP can regulate copper homeostasis by interacting with MURR1. BIRC8, also known as inhibitor of apoptosis-like protein 2, IAP-like protein 2, ILP-2, or testis-specific inhibitor of apoptosis, is a tissue-specific homolog of E3 ubiquitin-protein ligase XIAP. It has been implicated in the control of apoptosis in the testis by direct inhibition of caspase 9. Both XIAP and BIRC8 contain three N-terminal baculoviral IAP repeat (BIR) domains, a ubiquitin-association (UBA) domain and a C3HC4-type RING-HC finger at the carboxyl terminus.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....
gi 564362256 539 ALPMEEQLRKLQEERTCKVCMDREVSLVFIPCGHLVVCKECAPSLRKCPICRGTIKGTVRTFLS 602
Cdd:cd16714    1 EISTEEKLRRLQEEKLCKICMDRNISIVFIPCGHLVTCKQCAEALDKCPICCTVITFKQKIFMS 64

UBA domain found in baculoviral IAP repeat-containing protein BIRC2, BIRC3 and similar proteins; The subfamily includes cellular inhibitor of apoptosis protein 1 (c-IAP1) and c-IAP2. c-IAPs function as ubiquitin E3 ligases that mediate the ubiquitination of the substrates involved in apoptosis, nuclear factor-kappaB (NF-kappaB)signaling, and oncogenesis. Unlike other apoptosis proteins (IAPs), such as XIAP, c-IAPs exhibit minimal binding to caspases and may not play an important role in the inhibition of these proteases. c-IAP1, also called baculoviral IAP repeat-containing protein BIRC2, IAP-2, RING finger protein 48, or TNFR2-TRAF-signaling complex protein 2, is a potent regulator of the tumor necrosis factor (TNF) receptor family and NF-kappaB signaling pathways in the cytoplasm. It can also regulate E2F1 transcription factor-mediated control of cyclin transcription in the nucleus. c-IAP2, also called BIRC3, IAP-1, apoptosis inhibitor 2 (API2), or IAP homolog C, also influences ubiquitin-dependent pathways that modulate innate immune signalling by activation of NF-kappaB. c-IAPs contain three N-terminal baculoviral IAP repeat (BIR) domains that enable interactions with proteins, a ubiquitin-association (UBA) domain that is responsible for the binding of binds polyubiquitin (polyUb), a caspase activation and recruitment domain (CARD) that serves as a protein interaction surface, and a RING domain at the carboxyl terminus that is required for ubiquitin ligase activity.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|
gi 564362256 376 MNTPVVKAALDMGFSRSLVRQTVQRQILATGENYRTVSDLVIGLLDAEDE 425
Cdd:cd14394    1 MNTPVVKSALEMGFNRRLVKQTVQSKILTSGENYKTVNDLVSDLLSAEDE 50

Zinc finger, C3HC4 type (RING finger);

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 564362256  551 EERTCKVCMDREVSLVFIPCGHLVVCKECAPSLR----KCPICRGTIKGT 596
Cdd:pfam13920   1 EDLLCVICLDRPRNVVLLPCGHLCLCEECAERLLrkkkKCPICRQPIESV 50

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

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....
gi 564362256 555 CKVCMDREVSLVFIPCGHLVVCKECAPSLRKCPICRGTIKGTVR 598
Cdd:cd16515    4 CVVCMDAESQVIFLPCGHVCCCQTCSSSLSTCPLCRADITQRVR 47

UBA domain found in inhibitor of apoptosis proteins (IAPs); IAPs are frequently overexpressed in cancer and associated with tumor cell survival, chemoresistance, disease progression and poor prognosis. They function primarily as negative regulators of cell death. They regulate caspases and apoptosis through the inhibition of specific members of the caspase family of cysteine proteases. In addition, IAPs has been implicated in a multitude of other cellular processes, including inflammatory signalling and immunity, mitogenic kinase signalling, proliferation and mitosis, as well as cell invasion and metastasis. IAPs in this family includes cellular inhibitor of apoptosis protein c-IAP1 and c-IAP2, XIAP, and BIRC8, all of which contain three N-terminal baculoviral IAP repeat (BIR) domains that enable interactions with proteins, a ubiquitin-association (UBA) domain that is responsible for the binding of binds polyubiquitin (polyUb), and a RING domain at the carboxyl terminus that is required for ubiquitin ligase activity. c-IAPs contains an additional caspase activation and recruitment domain (CARD) between UBA and RING domains. CARD domain may serve as a protein interaction surface.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....
gi 564362256 379 PVVKAALDMGFSRSLVRQTVQRQILATGENYRTVSDLVIGLLDA 422
Cdd:cd14321    1 PVVQSALEMGFDRDRVRRAIERRLEETGRPFSTAEELVEAVLNA 44

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

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|..
gi 564362256 552 ERTCKVCMDREVSLVFIPCGHLVVCKECA-----PSLRKCPICRGTIKGTVR 598
Cdd:cd23128    3 ERECVMCMEEERSVVFLPCAHQVVCSGCNdlhekKGMRECPSCRGEIQERIR 54

RING finger, HC subclass, found in Arabidopsis thaliana protein XB3 homolog 5 (XBAT35) and similar proteins; XBAT35, also known as ankyrin repeat domain and RING finger-containing protein XBAT35, or RING-type E3 ubiquitin transferase XBAT35, has no E3 ubiquitin-protein ligase activity observed when associated with the E2 enzyme UBC8 in vitro. It contains a typical C3HC4-type RING-HC finger.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|.
gi 564362256 554 TCKVCMDREVSLVFIPCGHLVVCKECAPSL----RKCPICRGTIKGTVRTF 600
Cdd:cd23129    4 ECVVCMDAPRDAVCVPCGHVAGCMSCLKALmqssPLCPICRAPVRQVIKVY 54

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

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|...
gi 564362256 555 CKVCMDREVSLVFIPCGHLVVCKEC---APSLRKCPICRGTIK 594
Cdd:cd16648    4 CVICLSNPRSCVFLECGHVCSCIECyeaLPSPKKCPICRSFIK 46

RING finger, HC subclass, found in caspases-8 and -10-associated RING finger protein 2 (CARP-2) and similar proteins; CARP-2, also known as rififylin, caspase regulator CARP2, FYVE-RING finger protein Sakura (Fring), RING finger and FYVE-like domain-containing protein 1, RING finger protein 189 (RNF189), or RING finger protein 34-like, is an endosome-associated E3 ubiquitin-protein ligase that targets internalized receptor interacting kinase (RIP) for proteasome-mediated degradation. It acts as a negative regulator of tumor necrosis factor (TNF)-induced nuclear factor (NF)-kappaB activation. It also regulates the p53 signaling pathway by degrading 14-3-3sigma and stabilizing MDM2. As a caspase regulator, CARP2 does not localize to membranes in the cell and is involved in the negative regulation of apoptosis, specifically targeting two initiator caspases, caspase 8 and caspase 10. CARP2 contains an N-terminal FYVE-like domain and a C-terminal C3HC4-type RING-HC finger domain.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|
gi 564362256 551 EERTCKVCMDREVSLVFIPCGHLVVCKECAPSLRKCPICRGTIKGTVRTF 600
Cdd:cd16707    1 DENLCKICMDSPIDCVLLECGHMVTCTKCGKRMSECPICRQYVIRAVHVF 50

Modified RING finger, HC subclass (C3HC5-type), found in RING finger proteins, RNF26, RNF197 (CGRRF1), RNF156 (MGRN1), RNF157 and similar proteins; This subfamily corresponds to a group of RING finger proteins containing a modified C3HC5-type RING-HC finger, which is distinguished from typical C3HC4 RING-HC finger due to the existence of the additional cysteine residue in the middle portion of the RING finger domain. Cell growth regulator with RING finger domain protein 1 (CGRRF1), also known as cell growth regulatory gene 19 protein (CGR19) or RING finger protein 197 (RNF197), functions as a novel biomarker to monitor endometrial sensitivity and response to insulin-sensitizing drugs, such as metformin, in the context of obesity. RNF26 is an E3 ubiquitin ligase that temporally regulates virus-triggered type I interferon induction by increasing the stability of Mediator of IRF3 activation, MITA, also known as STING, through K11-linked polyubiquitination after viral infection and promoting degradation of IRF3, another important component required for virus-triggered interferon induction. Mahogunin ring finger-1 (MGRN1), also known as RING finger protein 156 (RNF156), is a cytosolic E3 ubiquitin-protein ligase that inhibits signaling through the G protein-coupled melanocortin receptors-1 (MC1R), -2 (MC2R) and -4 (MC4R) via ubiquitylation-dependent and -independent processes. It suppresses chaperone-associated misfolded protein aggregation and toxicity. RNF157 is a cytoplasmic E3 ubiquitin ligase predominantly expressed in the brain. It is a homolog of the E3 ligase MGRN1. In cultured neurons, it promotes neuronal survival in an E3 ligase-dependent manner. In contrast, it supports growth and maintenance of dendrites independent of its E3 ligase activity. RNF157 interacts with and ubiquitinates the adaptor protein APBB1 (amyloid beta precursor protein-binding, family B, member 1 or Fe65), which regulates neuronal survival, but not dendritic growth downstream of RNF157. The nuclear localization of APBB1 together with its interaction partner RNA-binding protein SART3 (squamous cell carcinoma antigen recognized by T cells 3 or Tip110) is crucial to trigger apoptosis.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|
gi 564362256 553 RTCKVCMDREVSLVFIPCGHLVVCKECAPSLR--KCPICR 590
Cdd:cd16649    1 GLCVVCLENPASVLLLPCRHLCLCEVCAKGLRgkTCPICR 40

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

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|.
gi 564362256 555 CKVCMDREVSLVFIPCGHLVVCKECAPSLRK-----CPICRGTIKGTVRTF 600
Cdd:cd16786    5 CTVCFDSEVDTVIYTCGHMCLCNSCGLKLKRqinacCPICRRVIKDVIKIY 55

Modified RING finger, HC subclass (C3HC5-type), found in cell growth regulator with RING finger domain protein 1 (CGRRF1) and similar proteins; CGRRF1, also known as cell growth regulatory gene 19 protein (CGR19) or RING finger protein 197 (RNF197), functions as a novel biomarker to monitor endometrial sensitivity and response to insulin-sensitizing drugs, such as metformin, in the context of obesity. CGRRF1 contains a C-terminal modified C3HC5-type RING-HC finger, which is distinguished from typical C3HC4 RING-HC finger due to the existence of the additional cysteine residue in the middle portion of the RING finger domain.

                         10        20        30
                 ....*....|....*....|....*....|....*.
gi 564362256 555 CKVCMDREVSLVFIPCGHLVVCKECAPSLRKCPICR 590
Cdd:cd16787    3 CVVCQNAPVNRVLLPCRHACVCDECFKRLQRCPMCR 38

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

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|..
gi 564362256 551 EER-TCKVCMDREVSLVFiPCGHlVVCKECAPSLRKCPICRGTIKGTVRTFL 601
Cdd:cd16728    2 EERiTCPICIDNHIKLVF-QCGH-GSCIECSSALKACPICRQAIRERIQIFV 51

Modified RING finger, HC subclass (C3HC5-type), found in mahogunin RING finger protein 1 (MGRN1), RING finger protein 157 (RNF157) and similar proteins; MGRN1, also known as RING finger protein 156 (RNF156), is a cytosolic E3 ubiquitin-protein ligase that inhibits signaling through the G protein-coupled melanocortin receptors-1 (MC1R), -2 (MC2R) and -4 (MC4R) via ubiquitylation-dependent and -independent processes. It suppresses chaperone-associated misfolded protein aggregation and toxicity. MGRN1 interacts with cytosolic prion proteins (PrPs) that are linked with neurodegeneration. It also interacts with expanded polyglutamine proteins, and suppresses misfolded polyglutamine aggregation and cytotoxicity. Moreover, MGRN1 inhibits melanocortin receptor signaling by competition with Galphas, suggesting a novel pathway for melanocortin signaling from the cell surface to the nucleus. MGRN1 also interacts with and ubiquitylates TSG101, a key component of the endosomal sorting complex required for transport (ESCRT)-I, and regulates endosomal trafficking. A null mutation in the gene encoding MGRN1 causes spongiform neurodegeneration, suggesting a link between dysregulation of endosomal trafficking and spongiform neurodegeneration. RNF157 is a cytoplasmic E3 ubiquitin ligase predominantly expressed in the brain. It is a homolog of the E3 ligase mahogunin ring finger-1 (MGRN1). In cultured neurons, it promotes neuronal survival in an E3 ligase-dependent manner. In contrast, it supports growth and maintenance of dendrites independent of its E3 ligase activity. RNF157 interacts with and ubiquitinates the adaptor protein APBB1 (amyloid beta precursor protein-binding, family B, member 1 or Fe65), which regulates neuronal survival, but not dendritic growth downstream of RNF157. The nuclear localization of APBB1 together with its interaction partner RNA-binding protein SART3 (squamous cell carcinoma antigen recognized by T cells 3 or Tip110) is crucial to trigger apoptosis. Both MGRN1 and RNF157 contain a modified C3HC5-type RING-HC finger, and a functionally uncharacterized region, known as domain associated with RING2 (DAR2), N-terminal to the RING finger. The C3HC5-type RING-HC finger is distinguished from typical C3HC4 RING-HC finger due to the existence of the additional cysteine residue in the middle portion of the RING finger domain.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|..
gi 564362256 553 RTCKVCMDREVSLVFIPCGHLVVCKECAPSLR----KCPICR 590
Cdd:cd16789    1 SECVICLSDPRDTAVLPCRHLCLCSDCAEVLRyqsnKCPICR 42

RING finger, HC subclass, found in Arabidopsis thaliana SP1-like protein 2 (SPL2) and similar proteins; SPL2, also known as RING-type E3 ubiquitin transferase SPL2, acts as an E3 ubiquitin-protein ligase that mediates E2-dependent protein ubiquitination. SPL2 contains a typical C3HC4-type RING-HC finger.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|..
gi 564362256 554 TCKVCMDREVSLVFIPCGHLVVCKECAPSLR-----KCPICR 590
Cdd:cd23145    5 LCVVCLLRRRRVAFIECGHRVCCELCARRVTreanpRCPVCR 46

RING finger, HC subclass, found in RNA-binding protein MEX3A; MEX3A, also known as RING finger and KH domain-containing protein 4 (RKHD4), is an RNA-binding phosphoprotein that localizes in P-bodies and stress granules, which are two structures involved in the storage and turnover of mRNAs. It has been implicated in the regulation of tumorigenesis. It controls the polarity and stemness of intestinal epithelial cells through the post-transcriptional regulation of the homeobox transcription factor CDX2, which plays a crucial role in intestinal cell fate specification, both during normal development and in tumorigenic processes involving intestinal reprogramming. Moreover, it exhibits a transforming activity when overexpressed in gastric epithelial cells. MEX3A contains two K homology (KH) domains that provide RNA-binding capacity, and a C-terminal C3HC4-type RING-HC finger. Like other MEX-3 family proteins, MEX3A shuttles between the nucleus and the cytoplasm via the CRM1-dependent export pathway.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|...
gi 564362256 553 RTCKVCMDREVSLVFIPCGHLVVCKECAPSL-----RKCPICRGTIKGTVRTF 600
Cdd:cd16720    3 RDCMVCFESEVTAALVPCGHNLFCMECAVRIcernePECPVCHALATQAIRIF 55

Modified RING finger, HC subclass (C3HC5-type), found in neuralized-like protein 1A (NEURL1A) and similar proteins; NEURL1A, also known as NEURL1, NEU, neuralized 1, or RING finger protein 67 (RNF67), is a mammalian homolog of the Drosophila neuralized (D-neu) protein. It functions as an E3 ubiquitin-protein ligase that directly interacts with and monoubiquitinates cytoplasmic polyadenylation element-binding protein 3 (CPEB3), an RNA binding protein and a translational regulator of local protein synthesis, which facilitates hippocampal plasticity and hippocampal-dependent memory storage. It also acts as a potential tumor suppressor that causes apoptosis and downregulates Notch target genes in the medulloblastoma. NEURL1A contains two neuralized homology regions (NHRs) responsible for Neural-ligand interactions and a modified C3HC5-type RING-HC finger required for ubiquitin ligase activity. The C3HC5-type RING-HC finger is distinguished from typical C3HC4-type RING-HC finger due to the existence of the additional cysteine residue in the middle portion of the RING finger domain.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|...
gi 564362256 555 CKVCMDREVSLVFIPCGHLVVCKECAPSLRK-----CPICRGTIKGTVRTFLS 602
Cdd:cd16785    7 CTICYENAVDTVIYTCGHMCLCYACGLRLKKmlnacCPICRRAIKDIIKTYRS 59

Caspase activation and recruitment domain found in Caspase-1 and related proteins; Caspase activation and recruitment domain (CARD) similar to those found in Caspase-1 (CASP1, ICE) and related proteins, including CARD-only proteins such as ICEBERG or CARD18, INCA (CARD17), CARD16 (COP1, PSEUDO-ICE), CARD8 (DACAR, NDPP1, TUCAN), and CARD12 (NLRC4), as well as ICE-like caspases such as CASP12, CASP5 (ICH-3) and CASP4 (TX, ICH-2). Caspases are aspartate-specific cysteine proteases with functions in apoptosis and immune signaling. CASP1 plays a central role in the cellular response to a wide variety of microbial and non-microbial stimuli, being activated by the inflammasome or the pyroptosome. CARD8 binds itself and the initiator caspase-9, interfering with the binding of APAF-1 and suppressing caspase-9 activation. CARD12 is a Nod-like receptor (NLR) that plays an important role in the innate immune response to Gram-negative bacteria. Caspase-4 (CASP4), -5 (CASP5), and -12 (CASP12) are inflammatory caspases implicated in inflammation and endoplasmic reticulum stress-induced apoptosis. In general, CARDs are death domains (DDs) found associated with caspases. They are known to be important in the signaling pathways for apoptosis, inflammation and host-defense mechanisms. DDs are protein-protein interaction domains found in a variety of domain architectures. Their common feature is that they form homodimers by self-association or heterodimers by associating with other members of the DD superfamily including PYRIN and DED (Death Effector Domain). They serve as adaptors in signaling pathways and can recruit other proteins into signaling complexes.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|...
gi 564362256 463 ILDCLLSARVITEQEYDAVKQKPHTL--QARTLIDTVLAKGNTAATSFRNSLQEIDPGLYRDI 523
Cdd:cd08325   21 LLDDLLEKNVLNEEEMEKIKEENNTIvdKARVLIDSVTEKGQMAGQIFIQHLCNRDKQLSSKL 83

RING finger, HC subclass, found in RING finger protein unkempt (UNK), unkempt-like (UNKL), and similar proteins; UNK, also known as zinc finger CCCH domain-containing protein 5, is a metazoan-specific zinc finger protein enriched in embryonic brains. It may play a broad regulatory role during the formation of the central nervous system (CNS). It is a sequence-specific RNA-binding protein required for early neuronal morphology. UNK is a neurogenic component of the mTOR pathway, and functions as a negative regulator of the timing of photoreceptor differentiation. It also specifically binds to Brg/Brm-associated factor BAF60b and promotes its ubiquitination in a Rac1-dependent manner. UNKL, also known as zinc finger CCCH domain-containing protein 5-like, is a putative E3 ubiquitin-protein ligase that may participate in a protein complex showing an E3 ligase activity regulated by RAC1. Both UNK and UNKL contain several tandem CCCH-type zinc fingers at the N-terminus, and a C3HC4-type RING-HC finger at its C-terminus.

                         10        20        30
                 ....*....|....*....|....*....|....*
gi 564362256 555 CKVCMDREVSLVFIPCGHLVVCKECAPSLRKCPIC 589
Cdd:cd16614    3 CMKCEERNRSVAVLPCQHYVLCEQCAETATECPYC 37

third RING finger, HC subclass, found in mind bomb 1 (MIB1) and similar proteins; MIB1, also known as DAPK-interacting protein 1 (DIP-1) or zinc finger ZZ type with ankyrin repeat domain protein 2, is a large, multi-domain E3 ubiquitin-protein ligase that promotes ubiquitination of the cytoplasmic tails of Notch ligands, and thus plays an essential role in controlling metazoan development by Notch signaling. It is also involved in Wnt/beta-catenin signaling and nuclear factor (NF)-kappaB signaling, and has been implicated in innate immunity, neuronal function, genomic stability, and cell death. MIB1 contains an MZM region with two Mib-Herc2 domains flanking a ZZ zinc finger, a REP region including two tandem Mib repeats, an ANK region that spans ankyrin repeats, and a RNG region consisting of three C3HC4-type RING-HC fingers. This model corresponds to the third RING-HC finger.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*.
gi 564362256 555 CKVCMDREVSLVFIpCGHlVVCKECAPSLRKCPICRGTIKGTVRTF 600
Cdd:cd16727    3 CPVCLDRLKNMIFL-CGH-GTCQLCGDRMSECPICRKAIEKRILLY 46

first RING finger, HC subclass, found in mind bomb 1 (MIB1) and similar proteins; MIB1, also known as DAPK-interacting protein 1 (DIP-1) or zinc finger ZZ type with ankyrin repeat domain protein 2, is a large, multi-domain E3 ubiquitin-protein ligase that promotes ubiquitination of the cytoplasmic tails of Notch ligands, and thus plays an essential role in controlling metazoan development by Notch signaling. It is also involved in Wnt/beta-catenin signaling and nuclear factor (NF)-kappaB signaling, and has been implicated in innate immunity, neuronal function, genomic stability, and cell death. MIB1 contains an MZM region with two Mib-Herc2 domains flanking a ZZ zinc finger, a REP region including two tandem Mib repeats, an ANK region that spans ankyrin repeats, and a RNG region consisting of three C3HC4-type RING-HC fingers. This model corresponds to the first RING-HC finger.

                         10        20        30
                 ....*....|....*....|....*....|....*.
gi 564362256 555 CKVCMDREVSLVFIPCGHLVVCKECAPSLRKCPICR 590
Cdd:cd16724    3 CMVCSDMKRDTLFGPCGHIATCSLCSPRVKKCLICK 38

RING finger, HC subclass, found in RNA-binding protein MEX3D; MEX3D, also known as RING finger and KH domain-containing protein 1 (RKHD1), RING finger protein 193 (RNF193), or TINO, is an RNA-binding phosphoprotein that controls the stability of the transcripts coding for the anti-apoptotic protein BCL-2, and negatively regulates BCL-2 in HeLa cells. MEX3D contains two K homology (KH) domains that provide RNA-binding capacity, and a C-terminal C3HC4-type RING-HC finger. Like other MEX-3 family proteins, MEX3D shuttles between the nucleus and the cytoplasm via the CRM1-dependent export pathway.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|...
gi 564362256 553 RTCKVCMDREVSLVFIPCGHLVVCKECA-----PSLRKCPICRGTIKGTVRTF 600
Cdd:cd16723   11 RECVVCFESEVIAALVPCGHNLFCMECAiricgKSEPECPACHTPATQAIHIF 63

Caspase activation and recruitment domain similar to that found in Apoptotic Protease-Activating Factor 1; Caspase activation and recruitment domain (CARD) similar to that found in apoptotic protease-activating factor 1 (APAF-1), which is an activator of caspase-9. APAF-1 contains WD-40 repeats, a CARD, and an ATPase domain. Upon stimulation, APAF-1, together with caspase-9, forms the heptameric 'apoptosome', which leads to the processing and activation of caspase-9, starting a caspase cascade which leads to apoptosis. In general, CARDs are death domains (DDs) found associated with caspases. They are known to be important in the signaling pathways for apoptosis, inflammation, and host-defense mechanisms. DDs are protein-protein interaction domains found in a variety of domain architectures. Their common feature is that they form homodimers by self-association or heterodimers by associating with other members of the DD superfamily including PYRIN and DED (Death Effector Domain). They serve as adaptors in signaling pathways and can recruit other proteins into signaling complexes.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|...
gi 564362256 463 ILDCLLSARVITEQEYDAVKQKPhTLQART--LIDTVLAKGNTAATSFRNSLqeIDPGlYRDI 523
Cdd:cd08323   19 IMDHMISDGVLTLSEEEKVRAQP-TQQERAaaLIKIILRKDNDAYISFYNAL--LHEG-YKDL 77

Modified RING finger, HC subclass (C3HC5-type), found in RING finger protein 26 (RNF26) and similar proteins; RNF26 is an E3 ubiquitin ligase that temporally regulates virus-triggered type I interferon induction by increasing the stability of Mediator of IRF3 activation, MITA, also known as STING, through K11-linked polyubiquitination of MITA after viral infection, and promoting the degradation of IRF3, another important component required for virus-triggered interferon induction. Although RNF26 substrates of ubiquitination remain unclear at present, RNF26 upregulation in gastric cancer might be implicated in carcinogenesis through dysregulation of growth regulators. RNF26 contains an N-terminal leucine zipper domain and a C-terminal modified C3HC5-type RING-HC finger, which is distinguished from typical C3HC4 RING-HC finger due to the existence of the additional cysteine residue in the middle portion of the RING finger domain.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*
gi 564362256 550 QEERTCKVCMDREVSLVFIPCGHLVVCKECAPSL-------RKCPICRGTIKGTV 597
Cdd:cd16788    3 RDKKKCVICQDQSKTVLILPCRHMCLCRQCANILlqqpvyrRNCPLCRTMILQTL 57

RING finger, HC subclass, found in tripartite motif-containing protein TRIM21 and similar proteins; TRIM21, also known as 52 kDa Ro protein, 52 kDa ribonucleoprotein autoantigen Ro/SS-A, Ro(SS-A), RING finger protein 81 (RNF81), or Sjoegren syndrome type A antigen (SS-A), is a ubiquitously expressed E3 ubiquitin-protein ligase and a high affinity antibody receptor uniquely expressed in the cytosol of mammalian cells. As a cytosolic Fc receptor, TRIM21 binds the Fc of virus-associated antibodies and targets the complex in the cytosol for proteasomal degradation in a process known as antibody-dependent intracellular neutralization (ADIN), and provides an intracellular immune response to protect host defense against pathogen infection. It shows remarkably broad isotype specificity as it does not only bind IgG, but also IgM and IgA. Moreover, TRIM21 promotes the cytosolic DNA sensor cGAS and the cytosolic RNA sensor RIG-I sensing of viral genomes during infection by antibody-opsonized virus. It stimulates inflammatory signaling and activates innate transcription factors, such as nuclear factor-kappaB (NF-kappaB). TRIM21 also plays an essential role in p62-regulated redox homeostasis, suggesting it may be a viable target for treating pathological conditions resulting from oxidative damage. Furthermore, TRIM21 may have implications for various autoimmune diseases associated with uncontrolled antiviral signaling through the regulation of Nmi-IFI35 complex-mediated inhibition of innate antiviral response. TRIM21 belongs to the C-IV subclass of the TRIM (tripartite motif) family of proteins that are defined by their N-terminal RBCC (RING, Bbox, and coiled coil) domains, including three consecutive zinc-binding domains, a C3HC4-type RING-HC finger, Bbox1 and Bbox2, and a coiled coil region, as well as a B30.2/SPRY (SplA and ryanodine receptor) domain positioned C-terminal to the RBCC domain.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|
gi 564362256 546 LRKLQEERTCKVCMDREVSLVFIPCGHlVVCKECAPSLRK-----CPICR 590
Cdd:cd16596    3 LTMMWEEVTCPICLDPFVEPVSIECGH-SFCQECISQVGKgggsvCPVCR 51

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

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*..
gi 564362256 555 CKVCMDREVSLVFIPCGHLvVCKECAPSLRK-----CPICRGTIKGT 596
Cdd:cd16708   24 CKICAENDKDVKIEPCGHL-MCTSCLTSWQEsegqgCPFCRCEIKGT 69

Modified RING finger, HC subclass (C2H2C4-type), found in protein MDM4 and similar proteins; MDM4, also known as double minute 4 protein (Hdm4), MDM2-like p53-binding protein, protein MDMX, HDMX, or p53-binding protein MDM4, exerts its oncogenic activity predominantly by binding p53 tumor suppressor and blocking its transcriptional activity. MDM4 is phosphorylated and destabilized in response to DNA damage stress. It can also be specifically dephosphorylated by directly interacting with protein phosphatase 1 (PP1), which may increase its stability and thus inhibit p53 activity. Meanwhile, MDM4 has a p53-independent role in tumorigenesis and cell growth regulation. MDM4 contains an N-terminal p53-binding domain and a C-terminal modified C2H2C4-type RING-HC finger responsible for its hetero-oligomerization, which is crucial for the suppression of P53 activity during embryonic development and the recruitment of E2 ubiquitin-conjugating enzymes. MDM4 also harbors a RanBP2-type zinc finger (zf-RanBP2) domain near the central acidic region.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....
gi 564362256 555 CKVCM--DREVSLVFIPCGHLVVCKECAPSLRK----CPICRGTIKGTVRTFLS 602
Cdd:cd16784    6 CSLCQkrPRNGNIVHGRTAHLVTCFHCARRLKKagapCPVCKKEIQMVIKIFIA 59