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Resolution of converging replication forks by RecQ and topoisomerase III.

ABSTRACT: RecQ-like DNA helicases pair with cognate topoisomerase III enzymes to function in the maintenance of genomic integrity in many organisms. These proteins play roles in stabilizing stalled replication forks, the S phase checkpoint response, and suppressing genetic crossovers, and their inactivation results in hyper-recombination, gross chromosomal rearrangements, chromosome segregation defects, and human disease. Biochemical activities associated with these enzymes include the ability to resolve double Holliday junctions, a process thought to lead to the suppression of crossover formation. Using Escherichia coli RecQ and topoisomerase III, we demonstrate a second activity for this pair of enzymes that could account for their role in maintaining genomic stability: resolution of converging replication forks. This resolution reaction is specific for the RecQ-topoisomerase III pair and is mediated by interaction of both of these enzymes with the single-stranded DNA-binding protein SSB.

SUBMITTER: Suski C

PROVIDER: S-EPMC2459239 | biostudies-literature | 2008 Jun

REPOSITORIES: biostudies-literature

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Resolution of converging replication forks by RecQ and topoisomerase III.

Suski Catherine C Marians Kenneth J KJ

Molecular cell 20080601 6

RecQ-like DNA helicases pair with cognate topoisomerase III enzymes to function in the maintenance of genomic integrity in many organisms. These proteins play roles in stabilizing stalled replication forks, the S phase checkpoint response, and suppressing genetic crossovers, and their inactivation results in hyper-recombination, gross chromosomal rearrangements, chromosome segregation defects, and human disease. Biochemical activities associated with these enzymes include the ability to resolve ...[more]

PMID: 18570879

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