PCNA is required for initiation of recombination-associated DNA synthesis by DNA polymerase delta.
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.
Li
Xuan
X
Department of Microbiology, University of California, Davis, 95616-8665, USA.
Stith
Carrie M
CM
Burgers
Peter M
PM
Heyer
Wolf-Dietrich
WD
D004247:DNA / Q000096:biosynthesis*; D004265:DNA Helicases; D004258:DNA Polymerase III / Q000378:metabolism*; D045643:DNA Repair Enzymes / Q000378:metabolism; D004259:DNA-Directed DNA Polymerase / Q000378:metabolism; D009690:Nucleic Acid Conformation; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism*; D051135:Rad51 Recombinase / Q000378:metabolism; D011995:Recombination, Genetic; D051818:Replication Protein C / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000201:enzymology*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism; D000099270:Y-Family DNA Polymerases
D004247:DNA; D004265:DNA Helicases; D004258:DNA Polymerase III; D045643:DNA Repair Enzymes; D004259:DNA-Directed DNA Polymerase; D018809:Proliferating Cell Nuclear Antigen; D051135:Rad51 Recombinase; D051818:Replication Protein C; D029701:Saccharomyces cerevisiae Proteins; C112338:Rad30 protein; D000099270:Y-Family DNA Polymerases; C075468:RAD54 protein, S cerevisiae