Nucleotide excision repair and homologous recombination systems commit differentially to the repair of DNA-protein crosslinks

Mol Cell. 2007 Oct 12;28(1):147-58. doi: 10.1016/j.molcel.2007.07.029.

Abstract

DNA-protein crosslinks (DPCs)-where proteins are covalently trapped on the DNA strand-block the progression of replication and transcription machineries and hence hamper the faithful transfer of genetic information. However, the repair mechanism of DPCs remains largely elusive. Here we have analyzed the roles of nucleotide excision repair (NER) and homologous recombination (HR) in the repair of DPCs both in vitro and in vivo using a bacterial system. Several lines of biochemical and genetic evidence show that both NER and HR commit to the repair or tolerance of DPCs, but differentially. NER repairs DPCs with crosslinked proteins of sizes less than 12-14 kDa, whereas oversized DPCs are processed exclusively by RecBCD-dependent HR. These results highlight how NER and HR are coordinated when cells need to deal with unusually bulky DNA lesions such as DPCs.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Azacitidine / metabolism
  • Chromosomes / genetics
  • Cross-Linking Reagents / metabolism
  • DNA / genetics
  • DNA / metabolism*
  • DNA Damage*
  • DNA Helicases / genetics
  • DNA Helicases / metabolism
  • DNA Repair*
  • DNA Replication*
  • Endodeoxyribonucleases / metabolism
  • Escherichia coli / metabolism
  • Escherichia coli Proteins / genetics
  • Escherichia coli Proteins / metabolism
  • Exodeoxyribonuclease V / genetics
  • Exodeoxyribonuclease V / metabolism
  • Formaldehyde / metabolism
  • Humans
  • Plasmids / genetics
  • Plasmids / metabolism
  • Recombination, Genetic*

Substances

  • Cross-Linking Reagents
  • Escherichia coli Proteins
  • RecG protein, E coli
  • Formaldehyde
  • DNA
  • Endodeoxyribonucleases
  • Exodeoxyribonuclease V
  • endodeoxyribonuclease uvrABC
  • Holliday junction DNA helicase, E coli
  • DNA Helicases
  • Azacitidine