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 323510634 382 NLLKPCSLCEKRPRDGNIIHGRTGHLVTCFHCARRLKKAGASCPICKKEIQLVIKVFIA 440
Cdd:cd16784    1 NLLEPCSLCQKRPRNGNIVHGRTAHLVTCFHCARRLKKAGAPCPVCKKEIQMVIKIFIA 59

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 323510634 382 NLLKPCSLCEKRPRDGNIIHGRTGHLVTCFHCARRLKKAGASCPICKKEIQLVIKVFIA 440
Cdd:cd16784    1 NLLEPCSLCQKRPRNGNIVHGRTAHLVTCFHCARRLKKAGAPCPVCKKEIQMVIKIFIA 59

Zn-finger in Ran binding protein and others;

                          10        20        30
                  ....*....|....*....|....*....|
gi 323510634  250 SEDEWQCTECKKFNSPSKRYCFRCWALRKD 279
Cdd:pfam00641   1 REGDWDCSKCLVQNFATSTKCVACQAPKPD 30

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 323510634 382 NLLKPCSLCEKRPRDGNIIHGRTGHLVTCFHCARRLKKAGASCPICKKEIQLVIKVFIA 440
Cdd:cd16784    1 NLLEPCSLCQKRPRNGNIVHGRTAHLVTCFHCARRLKKAGAPCPVCKKEIQMVIKIFIA 59

p53-binding domain found in E3 ubiquitin-protein ligase MDM2 and similar proteins; MDM2, also known as double minute 2 protein (Hdm2), or oncoprotein MDM2, or p53-binding protein, exerts its oncogenic activity predominantly by binding the p53 tumor suppressor and blocking its transcriptional activity. It forms homo-oligomers and displays E3 ubiquitin ligase activity, catalyzing the attachment of ubiquitin to p53 as an essential step in the regulation of its expression levels in cells. Moreover, in response to ribosomal stress, MDM2-mediated p53 ubiquitination and degradation can be inhibited through the interaction with ribosomal proteins L5, L11, and L23. MDM2 also has a p53-independent role in tumorigenesis and cell growth regulation. In addition, it binds interferon (IFN) regulatory factor-2 (IRF-2), an IFN-regulated transcription factor, and mediates its ubiquitination. MDM2 contains an N-terminal p53-binding domain and a C-terminal zinc RING-finger domain conferring E3 ligase activity that is required for ubiquitination and nuclear export of p53. It is also responsible for the hetero-oligomerization of MDM2, which is crucial for the suppression of P53 activity during embryonic development, and the recruitment of E2 ubiquitin-conjugating enzymes. MDM2 also harbors a RanBP2-type zinc finger (zf-RanBP2) domain, as well as a nuclear localization signal (NLS) and a nuclear export signal (NES), near the central acidic region.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 323510634  26 QVRPKLPLLKILHAAGAQGEMFTVKEVMHYLGQYIMVKQLYDQQEQHMVYCGGDLLGELLGRQSFSVKDPSPLYDMLRKN 105
Cdd:cd17672    3 LVRPKPLLLKLLKSAGAQKDTFTMKEVLFYLGQYIMAKQLYDEKQQHIVHCSNDPLGDLFGVQSFSVKEHRRIYAMISRN 82

                 .
gi 323510634 106 L 106
Cdd:cd17672   83 L 83

Modified RING finger, HC subclass (C2H2C4-type), found in E3 ubiquitin-protein ligase MDM2 and similar proteins; MDM2, also known as double minute 2 protein (Hdm2), oncoprotein MDM2, or p53-binding protein, exerts its oncogenic activity predominantly by binding p53 tumor suppressor and blocking its transcriptional activity. It forms homo-oligomers and displays E3 ubiquitin ligase activity that catalyzes the attachment of ubiquitin to p53 as an essential step in the regulation of its levels in cells. Moreover, in response to ribosomal stress, MDM2-mediated p53 ubiquitination and degradation can be inhibited through its interaction with ribosomal proteins L5, L11, and L23. MDM2 can be phosphorylated in the DNA damage. Meanwhile, MDM2 has a p53-independent role in tumorigenesis and cell growth regulation. In addition, it binds interferon (IFN) regulatory factor-2 (IRF-2), an IFN-regulated transcription factor, and mediates its ubiquitination. MDM2 contains an N-terminal p53-binding domain, and a C-terminal modified C2H2C4-type RING-HC finger conferring E3 ligase activity that is required for ubiquitination and nuclear export of p53. It is also responsible for the hetero-oligomerization of MDM2, which is crucial for the suppression of P53 activity during embryonic development, and the recruitment of E2 ubiquitin-conjugating enzymes. MDM2 also harbors a RanBP2-type zinc finger (zf-RanBP2) domain, as well as a nuclear localization signal (NLS) and a nuclear export signal (NES), near the central acidic region. The zf-RanBP2 domain plays an important role in mediating MDM2 binding to ribosomal proteins and thus is involved in MDM2-mediated p53 suppression.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*..
gi 323510634 384 LKPCSLCEKRPRDGNIIHGRTGHLVTCFHCARRLKKAGASCPICKKEIQLVIKVFIA 440
Cdd:cd16783    1 IEPCVICQTRPKNGCIVHGKTGHLMACFTCAKKLKKRNKPCPVCRQPIQMIVLTYFP 57

Zinc finger, C3HC4 type (RING finger);

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 323510634  385 KPCSLCEKRPRdgNIIHGRTGHLVTCFHCARRLKKAGASCPICKKEIQLV 434
Cdd:pfam13920   3 LLCVICLDRPR--NVVLLPCGHLCLCEECAERLLRKKKKCPICRQPIESV 50

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 323510634 387 CSLCEKRPRDGNIIhgRTGHLVTCFHCARRLKKAGASCPICKKEIQLVIKVF 438
Cdd:cd23129    5 CVVCMDAPRDAVCV--PCGHVAGCMSCLKALMQSSPLCPICRAPVRQVIKVY 54

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 323510634 387 CSLCEKRPRDGNIIhgRTGHLVTCFHCARRLKK-AGASCPICKKEIQLVIKVF 438
Cdd:cd16785    7 CTICYENAVDTVIY--TCGHMCLCYACGLRLKKmLNACCPICRRAIKDIIKTY 57

RING finger, HC subclass, 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 (BIRC2) and c-IAP2 (BIRC3), XIAP (BIRC4), BIRC7, 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 polyubiquitin (polyUb), and a C3HC4-type RING-HC finger at the carboxyl terminus that is required for ubiquitin ligase activity. The UBA domain is only absent in mammalian homologs of BIRC7. Moreover, c-IAPs contains an additional caspase activation and recruitment domain (CARD) between the UBA and C3HC4-type RING-HC domains. The CARD domain may serve as a protein interaction surface.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*
gi 323510634 385 KPCSLCekRPRDGNIIHGRTGHLVTCFHCARRLKKagasCPICKK 429
Cdd:cd16510    2 KLCKIC--MDREVNIVFLPCGHLVTCAQCAASLRK----CPICRT 40

RING finger, HC subclass, found in mind bomb MIB1, MIB2, RGLG1, RGLG2, and similar proteins; MIBs are large, multi-domain E3 ubiquitin-protein ligases that promote ubiquitination of the cytoplasmic tails of Notch ligands. They are also responsible for TBK1 K63-linked ubiquitination and activation, promoting interferon production and controlling antiviral immunity. Moreover, MIBs selectively control responses to cytosolic RNA and regulate type I interferon transcription. Both MIB1 and MIB2 have similar domain architectures, which consist of two Mib-Herc2 domains flanking a ZZ zinc finger, a REP region including two tandem Mib repeats, an ANK region that spans ankyrin repeats, and a RNG region, where MIB1 and MIB2 contain three and two C3HC4-type RING-HC fingers, respectively. This model corresponds to the third RING-HC finger of MIB1, as well as the second RING-HC finger of MIB2. In addition to MIB1 and MIB2, the RING-HC fingers of RING domain ligase RGLG1, RGLG2 and similar proteins from plant are also included in this model. RGLG1 is a ubiquitously expressed E3 ubiquitin-protein ligase that interacts with UBC13 and, together with UBC13, catalyzes the formation of K63-linked polyubiquitin chains, which is involved in DNA damage repair. RGLG1 mediates the formation of canonical, K48-linked polyubiquitin chains that target proteins for degradation. It also regulates apical dominance by acting on the auxin transport proteins abundance. RGLG1 has overlapping functions with its closest sequelog, RGLG2. They both function as RING E3 ligases that interact with ethylene response factor 53 (ERF53) in the nucleus and negatively regulate the plant drought stress response. All RGLG proteins contain a Von Willebrand factor type A (vWA) domain and a C3HC4-type RING-HC finger.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*
gi 323510634 387 CSLCEKRPRdgNIIHGrTGHlVTCFHCARRLKKagasCPICKKEI 431
Cdd:cd16520    3 CPICMERKK--NVVFL-CGH-GTCQKCAEKLKK----CPICRKPI 39