Replication and Recombination Factors Contributing to Recombination-Dependent Bypass of DNA Lesions by Template Switch

• DOI: 10.1371/journal.pgen.1001205
• Publication Date: 2010-11-11T21:34:44Z
• Authors: Fabio Vanoli; Marco Fumasoni; Barnabas Szakal; Laurent Maloisel; Dana Branzei
• Keywords: Replication protein A; DNA clamp; Postreplication repair

Damage tolerance mechanisms mediating damage-bypass and gap-filling are crucial for genome integrity. A major damage pathway involves recombination is referred to as template switch. Template switch intermediates were visualized by 2D gel electrophoresis in the proximity of replication forks X-shaped structures involving sister chromatid junctions. The homologous factor Rad51 required formation/stabilization these intermediates, but its mode action remains be investigated. By using a combination genetic physical approaches, we show that factors Rad55 Rad57, not Rad59, formation intermediates. replication-proficient recombination-defective rfa1-t11 mutant normal triggering checkpoint response following DNA impaired X-structure formation. Exo1 nuclease also has stimulatory roles this process. kinase, Rad53, X-molecule phosphorylates robustly damage. Although phosphorylation thought activate recombinational repair under conditions genotoxic stress, find phosphomutants do affect efficiency We examined polymerase implicated synthesis step Deficiencies translesion polymerases formation, whereas δ, bulk synthesis, plays an important role. Our data indicate subset factors, together with promote then preferentially dissolved Sgs1 helicase association Top3 topoisomerase rather than resolved Holliday Junction nucleases. results allow us propose choreography through which different players contribute distinguish process from other recombination-mediated processes promoting repair.