Isolation and Characterization of Mutations in the β-Tubulin Gene of SACCHAROMYCES CEREVISIAE

摘要: Of 173 mutants of Saccharomyces cerevisiae resistant to the antimitotic drug benomyl (BenR), six also conferred cold-sensitivity for growth and three others temperature-sensitivity in absence benomyl. All benR mutations tested, including nine conditional-lethal mutations, were shown be same gene. This gene, TUB2, has previously been molecularly cloned identified as yeast structural gene encoding beta-tubulin. Four alleles TUB2 mapped particular restriction fragments within One these was sequenced, revealing a single amino acid change, from arginine histidine at position 241, which is responsible both BenR cold-sensitive lethal phenotypes. The terminal arrest morphology their restrictive temperature showed characteristic cell-division-cycle defect, suggesting requirement tubulin function primarily mitosis during vegetative cycle. genetically distal left arm chromosome VI, very near actin ACT1; no CDC (cell-division-cycle) loci have this location. thus first known encode cytoskeletal protein that S. cerevisiae.