Conserved Protein Domain Family

cd16574: RING-HC_Topors 
RING finger, HC subclass, found in topoisomerase I-binding arginine/serine-rich protein (Topors) and similar proteins
Topors, also known as topoisomerase I-binding RING finger protein, tumor suppressor p53- binding protein 3, or p53-binding protein 3 (p53BP3), is a ubiquitously expressed nuclear E3 ubiquitin-protein ligase that can ligate both ubiquitin and small ubiquitin-like modifier (SUMO) to substrate proteins in the nucleus. It contains an N-terminal C3HC4-type RING-HC finger which ligates ubiquitin to its target proteins including DNA topoisomerase I, p53, NKX3.1, H2AX, and the AAV-2 Rep78/68 proteins. As a RING-dependent E3 ubiquitin ligase, Topors works with the E2 enzymes UbcH5a, UbcH5c, and UbcH6, but not with UbcH7, CDC34, or UbcH2b. Topors acts as a tumor suppressor in various malignancies. It regulates p53 modification, suggesting it may be responsible for astrocyte elevated gene-1 (AEG-1, also known as metadherin, or LYRIC) ubiquitin modification. Plk1-mediated phosphorylation of Topors inhibits Topors-mediated sumoylation of p53, whereas p53 ubiquitination is enhanced, leading to p53 degradation. It also functions as a negative regulator of the prostate tumor suppressor NKX3.1. Moreover, Topors is associated with promyelocytic leukemia nuclear bodies, and may be involved in the cellular response to camptothecin. It also plays a key role in the turnover of H2AX protein, discriminating the type of DNA damaging stress. Furthermore, Topors is a cilia-centrosomal protein associated with autosomal dominant retinal degeneration. Mutations in TOPORS cause autosomal dominant retinitis pigmentosa (adRP).
PSSM-Id: 319488
View PSSM: cd16574
Aligned: 29 rows
Threshold Bit Score: 66.888
Threshold Setting Gi: 124427796
Created: 2-May-2013
Updated: 18-Aug-2016
Aligned Rows:
Zn binding siteRING-HC finger
Feature 1:Zn binding site [ion binding site]
  • Comment:Based on the structural evidence that Homo sapiens RNF144A (1WIM) binds two Zn2+ ions through its C4C4-type RING finger.

Sequence Alignment
Format: Row Display: Color Bits: Type Selection:
                          10        20        30        40
Feature 1         #  #                # #  #  #          #  # 
gi 74752935   103 CPICLdrfd----nvsYLDRCLHKFCFRCVQEWSKnkaeCPLCK 142
gi 761951252   12 CSICLhtyk----draIVPTCSHEFCFGCILEWSEqsskCPLCN 51
gi 340380362   29 CPICLedyd----nkaFVNVCFHAFCYVCIVQWSEvsnkCPMCK 68
gi 124427796   12 CVICLnlms----nqvFMDQCNHSFCFECIRKWSEkshqCPQCR 51
gi 15230025   413 CGICLseedm-rrlkgTLDCCSHYFCFTCIMEWSKvesrCPLCK 455
gi 162697217   73 CGICLteee---vgrgKLDCCDHYFCFGCIMEWSKvesrCPICK 113
gi 928108986   44 CGICLteihrvdnprgRLNSCDHSFCSYCIKEWAKntnvCPLCK 87
gi 302765665   67 CGICFtddr----ergKLDCCDHFFCFGCIVEWSKlesrCPMCK 106
gi 470515796  128 CGICFeevk----ergVLDSCRHAFCFDCIHRWSKvansCPMCK 167
gi 545372465   46 CPICLgeifd-lrdkaVVISCMHVFCLACISRWSSlkksCPLCK 88

| Disclaimer | Privacy statement | Accessibility |
NCBI Home NCBI Search NCBI SiteMap