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PCNA is required for initiation of recombination-associated DNA synthesis by DNA polymerase delta.

ABSTRACT: Genetic recombination ensures proper chromosome segregation during meiosis and is essential for genome stability and tumor suppression. DNA synthesis after Rad51-mediated DNA strand invasion is a crucial step during recombination. PCNA is known as the processivity clamp for DNA polymerases. Here, we report the surprising observation that PCNA is specifically required to initiate recombination-associated DNA synthesis in the extension of the 3' end of the invading strand in a D loop. We show using a reconstituted system of yeast Rad51, Rad54, RPA, PCNA, RFC, and DNA polymerase delta that loading of PCNA by RFC targets DNA polymerase delta to the D loop formed by Rad51 protein, allowing efficient utilization of the invading 3' end and processive DNA synthesis. We conclude that PCNA has a specific role in the initiation of recombination-associated DNA synthesis and that DNA polymerase delta promotes recombination-associated DNA synthesis.

SUBMITTER: Li X

PROVIDER: S-EPMC2784891 | biostudies-literature | 2009 Nov

REPOSITORIES: biostudies-literature

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PCNA is required for initiation of recombination-associated DNA synthesis by DNA polymerase delta.

Li Xuan X Stith Carrie M CM Burgers Peter M PM Heyer Wolf-Dietrich WD

Molecular cell 20091101 4

Genetic recombination ensures proper chromosome segregation during meiosis and is essential for genome stability and tumor suppression. DNA synthesis after Rad51-mediated DNA strand invasion is a crucial step during recombination. PCNA is known as the processivity clamp for DNA polymerases. Here, we report the surprising observation that PCNA is specifically required to initiate recombination-associated DNA synthesis in the extension of the 3' end of the invading strand in a D loop. We show usin ...[more]

PMID: 19941829

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