Resolving individual steps of Okazaki-fragment maturation at a millisecond timescale

High-resolution kinetic analysis and enzyme trapping assays reveal how PCNA coordinates 5′-flap generation and processing by Pol δ and FEN1 during Okazaki-fragment maturation. DNA polymerase delta (Pol δ) is responsible for elongation and maturation of Okazaki fragments. Pol δ and the flap endonuclease FEN1, coordinated by the PCNA clamp, remove RNA primers and produce ligatable nicks. We studied this process in the Saccharomyces cerevisiae...