A Mutant Allele skt5 Affecting Protoplast Regeneration and Killer Toxin Resistance-Has Double Mutations in Its Wild-type Structural Gene in Saccharomyces cerevisiae

Abstract

Saccharomyces cerevisiae strains carrying the mutant allele skt5 are resistant to the killer toxin of Kluyveromyces lactis and are defective in protoplast regeneration. The DNA sequence analysis of the cloned mutant skt5 gene showed a nucleotide substitution (causing a glycine-to-glutamic acid substitution) and also a nucleotide insertion (causing a frameshift at the extreme carboxy-terminal region) in the structural region from its wild-type gene.