Recombination mediator and Rad51 targeting activities of a human BRCA2 polypeptide

Joseph San Filippo, Peter Chi, Michael G. Sehorn, Julia Etchin, Lumir Krejci, Patrick Sung

Research output: Contribution to journalArticlepeer-review

104 Scopus citations


BRCA2 likely exerts its tumor suppressor function by enhancing the efficiency of the homology-directed repair of injured chromosomes. To help define the DNA repair role of BRCA2, we expressed and purified a polypeptide, BRC3/4-DBD, that harbors its BRC3 and BRC4 repeats and DNA binding domain. BRC3/4-DBD interacted with hRad51 and bound DNA with a distinct preference for single-stranded (ss) DNA. Importantly we demonstrated by biochemical means and electron microscopy that BRC3/4-DBD nucleates hRad51 onto ssDNA and acts as a recombination mediator in enabling hRad51 to utilize replication protein A-coated ssDNA as recombination substrate. These functions of BRC3/4-DBD required both the BRC repeats and the BRCA2 DNA binding domain. The results thus clarify the role of BRCA2 in Rad51-dependent DNA recombination and repair, and the experimental strategies described herein should be valuable for systematically deciphering this BRCA2 function.

Original languageEnglish (US)
Pages (from-to)11649-11657
Number of pages9
JournalJournal of Biological Chemistry
Issue number17
StatePublished - Apr 28 2006
Externally publishedYes

ASJC Scopus subject areas

  • Molecular Biology
  • Biochemistry
  • Cell Biology


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