p53-binding domain found in MDM4 and similar proteins; MDM4, also known as double minute 4 protein, MDM2-like p53-binding protein, protein MDMX, HDMX, or p53-binding protein MDM4, exerts its oncogenic activity predominantly by binding the 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 through directly interacting with protein phosphatase 1 (PP1), which may increase its stability and thus inhibit p53 activity. MDM4 also has a p53-independent role in tumorigenesis and cell growth regulation. MDM4 contains an N-terminal p53-binding domain and a C-terminal zinc RING-finger domain 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        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 88702791  29 PKLPLLKILHAAGAQGEMFTVKEVMHYLGQYIMVKQLYDQQEQHMVYCGGDLLGELLGRQSFSVKDPSPLYDMLRKNLV 107
Cdd:cd17673   1 PKLPLLKILHAAGAQGEMFTVKEVMHYLGQYIMVKQLYDKQQQHIVYCGGDPLGELLGVQSFSVKDPSPLYDMLKRNLV 79

Zn-finger in Ran binding protein and others;

                          10        20        30
                  ....*....|....*....|....*....|
gi 88702791   300 SEDEWQCTECKKFNSPSKRYCFRCWALRKD 329
Cdd:pfam00641   1 REGDWDCSKCLVQNFATSTKCVACQAPKPD 30

p53-binding domain found in MDM4 and similar proteins; MDM4, also known as double minute 4 protein, MDM2-like p53-binding protein, protein MDMX, HDMX, or p53-binding protein MDM4, exerts its oncogenic activity predominantly by binding the 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 through directly interacting with protein phosphatase 1 (PP1), which may increase its stability and thus inhibit p53 activity. MDM4 also has a p53-independent role in tumorigenesis and cell growth regulation. MDM4 contains an N-terminal p53-binding domain and a C-terminal zinc RING-finger domain 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        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 88702791  29 PKLPLLKILHAAGAQGEMFTVKEVMHYLGQYIMVKQLYDQQEQHMVYCGGDLLGELLGRQSFSVKDPSPLYDMLRKNLV 107
Cdd:cd17673   1 PKLPLLKILHAAGAQGEMFTVKEVMHYLGQYIMVKQLYDKQQQHIVYCGGDPLGELLGVQSFSVKDPSPLYDMLKRNLV 79

Zinc finger, C3HC4 type (RING finger);

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 88702791   435 KPCSLCEKRPRdgNIIHGRTGHLVTCFHCARRLKKAGASCPICKKEIQLV 484
Cdd:pfam13920   3 LLCVICLDRPR--NVVLLPCGHLCLCEECAERLLRKKKKCPICRQPIESV 50

p53-binding domain found in MDM4 and similar proteins; MDM4, also known as double minute 4 protein, MDM2-like p53-binding protein, protein MDMX, HDMX, or p53-binding protein MDM4, exerts its oncogenic activity predominantly by binding the 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 through directly interacting with protein phosphatase 1 (PP1), which may increase its stability and thus inhibit p53 activity. MDM4 also has a p53-independent role in tumorigenesis and cell growth regulation. MDM4 contains an N-terminal p53-binding domain and a C-terminal zinc RING-finger domain 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        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 88702791  29 PKLPLLKILHAAGAQGEMFTVKEVMHYLGQYIMVKQLYDQQEQHMVYCGGDLLGELLGRQSFSVKDPSPLYDMLRKNLV 107
Cdd:cd17673   1 PKLPLLKILHAAGAQGEMFTVKEVMHYLGQYIMVKQLYDKQQQHIVYCGGDPLGELLGVQSFSVKDPSPLYDMLKRNLV 79

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 88702791  26 QVRPKLPLLKILHAAGAQGEMFTVKEVMHYLGQYIMVKQLYDQQEQHMVYCGGDLLGELLGRQSFSVKDPSPLYDMLRKN 105
Cdd:cd17672   3 LVRPKPLLLKLLKSAGAQKDTFTMKEVLFYLGQYIMAKQLYDEKQQHIVHCSNDPLGDLFGVQSFSVKEHRRIYAMISRN 82

                .
gi 88702791 106 L 106
Cdd:cd17672  83 L 83

Modified RING finger, HC subclass (C2H2C4-type), found in E3 ubiquitin-protein ligase MDM2, protein MDM4 and similar proteins; MDM2 (also known as HDM2) and MDM4 (also known as MDMX or HDMX) are the primary p53 tumor suppressor negative regulators. They have non-redundant roles in the regulation of p53. MDM2 mainly functions to control p53 stability, while MDM4 controls p53 transcriptional activity. Both MDM2 and MDM4 contain an N-terminal p53-binding domain, a RanBP2-type zinc finger (zf-RanBP2) domain near the central acidic region, and a C-terminal modified C2H2C4-type RING-HC finger. Mdm2 can form homo-oligomers through its RING domain 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. Despite its RING domain and structural similarity with MDM2, MDM4 does not homo-oligomerize and lacks ubiquitin-ligase function, but inhibits the transcriptional activity of p53. In addition, both their RING domains are responsible for the hetero-oligomerization, which is crucial for the suppression of P53 activity during embryonic development and the recruitment of E2 ubiquitin-conjugating enzymes. Moreover, MDM2 and MDM4 can be phosphorylated and destabilized in response to DNA damage stress. In response to ribosomal stress, MDM2-mediated p53 ubiquitination and degradation can be inhibited through the interaction with ribosomal proteins L5, L11, and L23. However, MDM4 is not bound to ribosomal proteins, suggesting its different response to regulation by small basic proteins such as ribosomal proteins and ARF.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|.
gi 88702791 436 PCSLCEKRPRDGNIIHGRTGHLVTCFHCARRLKKAGASCPICKKEIQLVIK 486
Cdd:cd16646   2 LCVICLSRPRTAAIVHGKTGHQVACYTCAKKLKRRGKPCPVCRRPIQNVIK 52

Modified RING finger, HC subclass (C3HC5-type), found in neuralized-like protein NEURL1A, NEURL1B, and similar proteins; This subfamily includes Drosophila neuralized (D-neu) protein, and its two mammalian homologs, NEURL1A and NEURL1B. D-neu is a regulator of the developmentally important Notch signaling pathway. NEURL1A, also known as NEURL1, NEU, neuralized 1, or RING finger protein 67 (RNF67), is a mammalian homolog of D-neu. 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 medulloblastoma. NEURL1B, also known as neuralized-2 (NEUR2) or neuralized-like protein 3, is another mammalian homolog of 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 by working cooperatively with another E3 ligase, Mind bomb-1 (Mib1), in Delta endocytosis to hepatocyte growth factor-regulated tyrosine kinase substrate (Hrs)-positive vesicles. Members of this subfamily contain 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 88702791 436 PCSLCEKRPRDGNIIhgRTGHLVTCFHCARRLKKAGASCPICKKEIQLVIKVF 488
Cdd:cd16647   3 ECVICYERPVDTVLY--RCGHMCMCYDCALQLKRRGGSCPICRAPIKDVIKIY 53

Zn-finger in Ran binding protein and others;

                          10        20        30
                  ....*....|....*....|....*....|
gi 88702791   300 SEDEWQCTECKKFNSPSKRYCFRCWALRKD 329
Cdd:pfam00641   1 REGDWDCSKCLVQNFATSTKCVACQAPKPD 30

SWIB/MDM2 domain family; The SWIB/MDM2 protein domain, short for SWI/SNF complex B/MDM2, has been found in both SWI/SNF complex B (SWIB) and the negative regulator of the p53 tumor suppressor MDM2, which are homologous and share a common fold. The SWIB domain is a conserved region found within proteins in the SWI/SNF (SWItch/Sucrose Non-Fermentable) family of complexes. SWI/SNF complex proteins display helicase and ATPase activities and are thought to regulate transcription of certain genes by altering the chromatin structure around those genes. The mammalian complexes are made up of 9-12 proteins called BAFs (BRG1-associated factors). MDM2 is an inhibitor of p53 tumor repressor. It binds to the transactivation domain and down-regulates the ability of p53 to activate transcription. This family corresponds to the SWIB domain and the p53 binding domain of MDM2.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 88702791  32 PLLKILHAAgaqgEMFTVKEVMHYLGQYIMVKQLYDQQEQHMVYCggdllgELLGRQSFSVKD--PSPLYDMLRKN 105
Cdd:cd00855   4 ELEALLKSY----ETFTLKEILQALWQYIKKKNLMDPDDPSIVVC------DERLRQLFEVPSfpFSEIPKALKKH 69

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
                ....*....|....*....|....*....|....*
gi 88702791 455 GHLVTCFHCARRLKK-AGASCPICKKEIQLVIKVF 488
Cdd:cd16786  21 GHMCLCNSCGLKLKRqINACCPICRRVIKDVIKIY 55

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 88702791 437 CSLCEKRPRdgNIIHGrTGHlVTCFHCARRLKKagasCPICKKEI 481
Cdd:cd16520   3 CPICMERKK--NVVFL-CGH-GTCQKCAEKLKK----CPICRKPI 39

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 88702791 437 CSLCEKRPRDGNIIHgrTGHLVTCFHCARRLKK-AGASCPICKK 479
Cdd:cd23145   6 CVVCLLRRRRVAFIE--CGHRVCCELCARRVTReANPRCPVCRQ 47