Related Experiment Video
Updated: Jun 18, 2026

Laser Micro-Irradiation to Study DNA Recruitment During S Phase
Published on: April 16, 2021
PCNA is required for initiation of recombination-associated DNA synthesis by DNA polymerase delta
Xuan Li1, Carrie M Stith, Peter M Burgers
1Department of Microbiology, University of California, Davis, 95616-8665, USA.
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.
Related Concept Videos
Homologous Recombination
Restarting Stalled Replication Forks
S-Cdk Initiates DNA Replication
Two states at the origin of replication
In eukaryotes, the initiation of replication occurs at many sites on the chromosomes, called the origins of replication.
S-Cdk Initiates DNA Replication
Two states at the origin of replication
In eukaryotes, the initiation of replication occurs at many sites on the chromosomes, called the origins of replication.
Conservative Site-specific Recombination and Phase Variation
The recognition sites for Cre recombinase called LoxP...
The Replisome
The synthesis of the leading and lagging strands is a highly coordinated process. To explain this, the “Trombone model” was proposed by Bruce Alberts in 1980. The DNA loop formation starts when a primer is synthesized on the parent lagging strand. The loop grows with the...
