Unconventional ubiquitin recognition by the ubiquitin-binding motif within the Y family DNA polymerases iota and Rev1

Mol Cell. 2010 Feb 12;37(3):408-17. doi: 10.1016/j.molcel.2009.12.038.

Abstract

Translesion synthesis is an essential cell survival strategy to promote replication after DNA damage. The accumulation of Y family polymerases (pol) iota and Rev1 at the stalled replication machinery is mediated by the ubiquitin-binding motifs (UBMs) of the polymerases and enhanced by PCNA monoubiquitination. We report the solution structures of the C-terminal UBM of human pol iota and its complex with ubiquitin. Distinct from other ubiquitin-binding domains, the UBM binds to the hydrophobic surface of ubiquitin centered at L8. Accordingly, mutation of L8A, but not I44A, of ubiquitin abolishes UBM binding. Human pol iota contains two functional UBMs, both contributing to replication foci formation. In contrast, only the second UBM of Saccharomyces cerevisiae Rev1 binds to ubiquitin and is essential for Rev1-dependent cell survival and mutagenesis. Point mutations disrupting the UBM-ubiquitin interaction also impair the accumulation of pol iota in replication foci and Rev1-mediated DNA damage tolerance in vivo.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • DNA Damage
  • DNA Polymerase iota
  • DNA-Directed DNA Polymerase / chemistry*
  • DNA-Directed DNA Polymerase / metabolism
  • Humans
  • Molecular Sequence Data
  • Nucleotidyltransferases / chemistry
  • Nucleotidyltransferases / metabolism*
  • Protein Structure, Tertiary
  • Saccharomyces cerevisiae / genetics
  • Saccharomyces cerevisiae / metabolism
  • Saccharomyces cerevisiae Proteins / chemistry
  • Saccharomyces cerevisiae Proteins / metabolism*
  • Sequence Alignment
  • Ubiquitin / chemistry*
  • Ubiquitin / metabolism
  • Ubiquitination

Substances

  • Saccharomyces cerevisiae Proteins
  • Ubiquitin
  • Nucleotidyltransferases
  • REV1 protein, S cerevisiae
  • DNA-Directed DNA Polymerase
  • DNA Polymerase iota