Molecular dissection of mitotic recombination in the yeast Saccharomyces cerevisiae.
Recombination plays a central role in the repair of broken chromosomes in all eukaryotes. We carried out a systematic study of mitotic recombination. Using several assays, we established the chronological sequence of events necessary to repair a single double-strand break. Once a chromosome is broken, yeast cells become immediately committed to recombinational repair. Recombination is completed within an hour and exhibits two kinetic gaps. By using this kinetic framework we also characterized the role played by several proteins in the recombinational process. In the absence of Rad52, the broken chromosome ends, both 5' and 3', are rapidly degraded. This is not due to the inability to recombine, since the 3' single-stranded DNA ends are stable in a strain lacking donor sequences. Rad57 is required for two consecutive strand exchange reactions. Surprisingly, we found that the Srs2 helicase also plays an early positive role in the recombination process.
Aylon
Yael
Y
Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Ramat Aviv 69978, Israel.
Liefshitz
Batia
B
Bitan-Banin
Gili
G
Kupiec
Martin
M
D000251:Adenosine Triphosphatases; D004247:DNA / Q000235:genetics; D004265:DNA Helicases / Q000502:physiology; D004260:DNA Repair / Q000235:genetics; D045643:DNA Repair Enzymes; D004271:DNA, Fungal / Q000096:biosynthesis; D004277:DNA, Single-Stranded / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D005656:Fungal Proteins / Q000235:genetics / Q000502:physiology; D005785:Gene Conversion; D008938:Mitosis; D051721:Rad52 DNA Repair and Recombination Protein; D011995:Recombination, Genetic; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology
D004271:DNA, Fungal; D004277:DNA, Single-Stranded; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; C497197:RAD52 protein, S cerevisiae; D051721:Rad52 DNA Repair and Recombination Protein; D029701:Saccharomyces cerevisiae Proteins; C061376:SRS2 protein, S cerevisiae; D004247:DNA; D000251:Adenosine Triphosphatases; C071451:RAD57 protein, S cerevisiae; D004265:DNA Helicases; D045643:DNA Repair Enzymes