There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.
Abstract
Mitotic double-strand break (DSB)-induced gene conversion at MAT in Saccharomyces
cerevisiae was analyzed molecularly in mutant strains thermosensitive for essential
replication factors. The processivity cofactors PCNA and RFC are essential even to
synthesize as little as 30 nucleotides following strand invasion. Both PCNA-associated
DNA polymerases delta and epsilon are important for gene conversion, though a temperature-sensitive
Pol epsilon mutant is more severe than one in Pol delta. Surprisingly, mutants of
lagging strand replication, DNA polymerase alpha (pol1-17), DNA primase (pri2-1),
and Rad27p (rad27 delta) also greatly inhibit completion of DSB repair, even in G1-arrested
cells. We propose a novel model for DSB-induced gene conversion in which a strand
invasion creates a modified replication fork, involving leading and lagging strand
synthesis from the donor template. Replication is terminated by capture of the second
end of the DSB.