Analysis of mitotic and meiotic defects in Saccharomyces cerevisiae SRS2 DNA helicase mutants.

摘要: The hyper-gene conversion srs2-101 mutation of the SRS2 DNA helicase gene Saccharomyces cerevisiae has been reported to suppress UV sensitivity rad18 mutants. New alleles were recovered using this suppressor phenotype. have characterized with respect suppression sensitivity, hyperrecombination, reduction meiotic viability, and definition mutational change within gene. Variability in degree hyperrecombination found. that showed severest effects found be missense mutations consensus domains family proteins. effect I (ATP-binding) V (proposed binding) are reported. Some reduce spore viability 50% wild-type levels. This phenotype is not bypassed by spo13 mutation. Although srs2 homozygous diploids strains undergo normal commitment recombination, event delayed several hours mutant appear stall progression from meiosis II.