Recombination hotspots attenuate the coupled ATPase and translocase activities of an AddAB-type helicase-nuclease.

ABSTRACT: In all domains of life, the resection of double-stranded DNA breaks to form long 3'-ssDNA overhangs in preparation for recombinational repair is catalyzed by the coordinated activities of DNA helicases and nucleases. In bacterial cells, this resection reaction is modulated by the recombination hotspot sequence Chi. The Chi sequence is recognized in cis by translocating helicase-nuclease complexes such as the Bacillus subtilis AddAB complex. Binding of Chi to AddAB results in the attenuation of nuclease activity on the 3'-terminated strand, thereby promoting recombination. In this work, we used stopped-flow methods to monitor the coupling of adenosine triphosphate (ATP) hydrolysis and DNA translocation and how this is affected by Chi recognition. We show that in the absence of Chi sequences

SUBMITTER: Gilhooly NS 

PROVIDER: S-EPMC4027173 | biostudies-literature | 2014 May

REPOSITORIES: biostudies-literature