title: MAL63 codes for a positive regulator of maltose fermentation in Saccharomyces cerevisiae.
abstract: Genetic analysis of the MAL6 locus has previously yielded mal6 mutants which fall into a single complementation group and which are noninducible for maltase and maltose permease. However, the strains used in these studies contained additional partially functional copies of MAL1 (referred to as MAL1g) and MAL3 (referred to as MAL3g). Using a strain lacking MALg genes, we have isolated two classes of mutants and these classes correspond to mutations in MAL63 and MAL61, two genes of the MAL6 complex. Disruptions of MAL63 are noninducible for maltase and maltose permease and for their corresponding mRNAs. The mal6 mutants are shown to map to MAL63. Inducer exclusion as a cause of the noninducible phenotype of the mal63 mutations has been eliminated by constructing a mal63 mutant in a strain constitutive for maltose permease; the strain remains noninducible. These results rigorously demonstrate that MAL63 is a regulatory gene which plays a positive role in the regulation of maltose fermentation.
authors.affiliation: Department of Biochemistry, Wayne State University School of Medicine, Detroit, MI 48201.
authors.forename: Y S
authors.initials: YS
authors.lastname: Chang
authors.forename: R A
authors.initials: RA
authors.lastname: Dubin
authors.forename: E
authors.initials: E
authors.lastname: Perkins
authors.forename: D
authors.initials: D
authors.lastname: Forrest
authors.forename: C A
authors.initials: CA
authors.lastname: Michels
authors.forename: R B
authors.initials: RB
authors.lastname: Needleman
mesh_terms: D002874:Chromosome Mapping; D004790:Enzyme Induction; D005285:Fermentation; D005800:Genes, Fungal; D005816:Genetic Complementation Test; D008320:Maltose / Q000378:metabolism*; D026901:Membrane Transport Proteins / Q000235:genetics; D009004:Monosaccharide Transport Proteins; D009154:Mutation; D010957:Plasmids; D012045:Regulatory Sequences, Nucleic Acid; D015183:Restriction Mapping; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D000520:alpha-Glucosidases / Q000235:genetics
chemical_list: D026901:Membrane Transport Proteins; D009004:Monosaccharide Transport Proteins; D008320:Maltose; C021534:maltose permease; D000520:alpha-Glucosidases