Effects of mutations of RAD50, RAD51, RAD52, and related genes on illegitimate recombination in Saccharomyces cerevisiae.
To examine the mechanism of illegitimate recombination in Saccharomyces cerevisiae, we have developed a plasmid system for quantitative analysis of deletion formation. A can1 cyh2 cell carrying two negative selection markers, the CAN1 and CYH2 genes, on a YCp plasmid is sensitive to canavanine and cycloheximide, but the cell becomes resistant to both drugs when the plasmid has a deletion over the CAN1 and CYH2 genes. Structural analysis of the recombinant plasmids obtained from the resistant cells showed that the plasmids had deletions at various sites of the CAN1-CYH2 region and there were only short regions of homology (1-5 bp) at the recombination junctions. The results indicated that the deletion detected in this system were formed by illegitimate recombination. Study on the effect of several rad mutations showed that the recombination rate was reduced by 30-, 10-, 10-, and 10-fold in the rad52, rad50, mre11, and xrs2 mutants, respectively, while in the rad51, 54, 55, and 57 mutants, the rate was comparable to that in the wild-type strain. The rad52 mutation did not affect length of homology at junction sites of illegitimate recombination.
Tsukamoto
Y
Y
Department of Molecular Biology, Univesity of Tokyo, Japan.
Kato
J
J
Ikeda
H
H
D000251:Adenosine Triphosphatases; D001483:Base Sequence; D004265:DNA Helicases; D017931:DNA Primers; D004260:DNA Repair; D045643:DNA Repair Enzymes; D004271:DNA, Fungal; D004268:DNA-Binding Proteins / Q000235:genetics; D004706:Endodeoxyribonucleases; D005090:Exodeoxyribonucleases; D005656:Fungal Proteins / Q000235:genetics*; D017353:Gene Deletion; D005800:Genes, Fungal; D008969:Molecular Sequence Data; D010957:Plasmids; D051135:Rad51 Recombinase; D051721:Rad52 DNA Repair and Recombination Protein; D011995:Recombination, Genetic; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins
D017931:DNA Primers; D004271:DNA, Fungal; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; C086930:RAD50 protein, S cerevisiae; C497197:RAD52 protein, S cerevisiae; C087191:RAD55 protein, S cerevisiae; D051721:Rad52 DNA Repair and Recombination Protein; D029701:Saccharomyces cerevisiae Proteins; C086929:XRS2 protein, S cerevisiae; C495151:RAD51 protein, S cerevisiae; D051135:Rad51 Recombinase; D004706:Endodeoxyribonucleases; D005090:Exodeoxyribonucleases; C094191:MRE11 protein, S cerevisiae; D000251:Adenosine Triphosphatases; C075468:RAD54 protein, S cerevisiae; C071451:RAD57 protein, S cerevisiae; D004265:DNA Helicases; D045643:DNA Repair Enzymes