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RecA-mediated strand exchange traverses substitutional heterologies more easily than deletions or insertions.

ABSTRACT: RecA protein in bacteria and its eukaryotic homolog Rad51 protein are responsible for initiation of strand exchange between homologous DNA molecules. This process is crucial for homologous recombination, the repair of certain types of DNA damage and for the reinitiation of DNA replication on collapsed replication forks. We show here, using two different types of in vitro assays, that in the absence of ATP hydrolysis RecA-mediated strand exchange traverses small substitutional heterologies between the interacting DNAs, whereas small deletions or insertions block the ongoing strand exchange. We discuss evolutionary implications of RecA selectivity against insertions and deletions and propose a molecular mechanism by which RecA can exert this selectivity.

SUBMITTER: Bucka A

PROVIDER: S-EPMC55751 | biostudies-literature | 2001 Jun

REPOSITORIES: biostudies-literature

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RecA-mediated strand exchange traverses substitutional heterologies more easily than deletions or insertions.

Bucka A A Stasiak A A

Nucleic acids research 20010601 12

RecA protein in bacteria and its eukaryotic homolog Rad51 protein are responsible for initiation of strand exchange between homologous DNA molecules. This process is crucial for homologous recombination, the repair of certain types of DNA damage and for the reinitiation of DNA replication on collapsed replication forks. We show here, using two different types of in vitro assays, that in the absence of ATP hydrolysis RecA-mediated strand exchange traverses small substitutional heterologies betwee ...[more]

PMID: 11410652

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