Rad54 plays key roles in homologous recombination (HR) and double-strand break (DSB) repair in yeast, along with Rad51, Rad52, Rad55 and Rad57. Rad54 belongs to the Swi2/Snf2 family of DNA-stimulated ATPases. Rad51 nucleoprotein filaments catalyze DNA strand exchange and Rad54 augments this activity of Rad51. Mutations in the Rad54 ATPase domain (ATPase-) impair Rad54 function in vitro, sensitize yeast to killing by methylmethane sulfonate and reduce spontaneous gene conversion. We found that overexpression of ATPase- Rad54 reduced spontaneous direct repeat gene conversion and increased both spontaneous direct repeat deletion and spontaneous allelic conversion. Overexpression of ATPase- Rad54 decreased DSB-induced allelic conversion, but increased chromosome loss and DSB-dependent lethality. Thus, ATP hydrolysis by Rad54 contributes to genome stability by promoting high-fidelity DSB repair and suppressing spontaneous deletions. Overexpression of wild-type Rad54 did not alter DSB-induced HR levels, but conversion tract lengths were reduced. Interestingly, ATPase- Rad54 decreased overall HR levels and increased tract lengths. These tract length changes provide new in vivo evidence that Rad54 functions in the post-synaptic phase during recombinational repair of DSBs.
|Original language||English (US)|
|Number of pages||9|
|Journal||Nucleic Acids Research|
|State||Published - Jul 1 2002|
ASJC Scopus subject areas