Role of allosteric switch residue histidine 195 in maintaining active-site asymmetry in presynaptic filaments of bacteriophage T4 UvsX recombinase.

ABSTRACT: Recombinases of the highly conserved RecA/Rad51 family play central roles in homologous recombination and DNA double-stranded break repair. RecA/Rad51 enzymes form presynaptic filaments on single-stranded DNA (ssDNA) that are allosterically activated to catalyze ATPase and DNA strand-exchange reactions. Information is conveyed between DNA- and ATP-binding sites, in part, by a highly conserved glutamine residue (Gln194 in Escherichia coli RecA) that acts as an allosteric switch. The T4 UvsX protein is a divergent RecA ortholog and contains histidine (His195) in place of glutamine at the allosteric switch position. UvsX and RecA catalyze similar strand-exchange reactions, but differ in other properties. UvsX produces both ADP and AMP as products of its ssDNA-dependent ATPase activity--a prop

SUBMITTER: Farb JN 

PROVIDER: S-EPMC2888526 | biostudies-literature | 2009 Jan

REPOSITORIES: biostudies-literature