Uninducible Mutants in the gal i Locus of Saccharomyces cerevisiae

Abstract

Uninducible galactose nonfermenter mutants of Saccharomyces cerevisiae have been isolated and mapped in the gal i locus. They appear to be analogous to the i ^s mutations found in the regulatory genes of the Escherichia coli lactose and galactose systems. The susceptibility to suppression by an ochre suppressor of an i allele in an i ^s i ⁻ double mutant suggests that the i locus in S. cerevisiae codes for a protein.