TITLE:
Rad51 ATP binding but not hydrolysis is required to recruit Rad10 in synthesis-dependent strand annealing sites in S. cerevisiae
AUTHORS:
Justin Karlin, Paula L. Fischhaber
KEYWORDS:
Rad1; Rad10; Rad51; Synthesis Dependent Strand Annealing; Yeast; Double Strand Break Repair
JOURNAL NAME:
Advances in Biological Chemistry,
Vol.3 No.3,
June
25,
2013
ABSTRACT:
Several modes of eukaryotic of DNA double strand break
repair (DSBR) depend on synapsis of complementary DNA. The Rad51 ATPase, the S.
cerevisiae homolog of E. coli RecA, plays a key role in this process
by catalyzing homology searching and strand exchange between an invading DNA
strand and a repair template (e.g. sister chromatid or homologous chromosome).
Synthesis dependent strand annealing (SDSA), a mode of DSBR, requires Rad51.
Another repair enzyme, the Rad1-Rad10 endonuclease, acts in the final stages of
SDSA, hydrolyzing 3￠ overhanging
single-stranded DNA. Here we show in vivo by fluo-rescence microscopy that the ATP binding function of yeast Rad51 is required to recruit
Rad10 SDSA sites indicating that Rad51 pre-synaptic filament formation must
occur prior to the recruitment of Rad1-Rad10. Our data also show that Rad51 ATPase
activity, an important step in Rad51 filament disassembly, is not absolutely
required in order to recruit Rad1- Rad10 to DSB sites.