MAL6 of Saccharomyces: a complex genetic locus containing three genes required for maltose fermentation.

Publisher Website
Google Scholar
Abstract
The MAL6 locus is 1 of 5 closely related unlinked loci, any one of which is sufficient for fermentation of maltose in Saccharomyces. Previous genetic analysis indicated that this locus is defined by 2 complementation groups, MALp and MALg. MALp reportedly is a regulatory gene required for inducible synthesis of the 2 enzymatic functions needed for fermentation: maltose permease and maltase. The physical and genetic structure of the MAL6 locus, which was isolated on a recombinant DNA plasmid was investigated. One subclone of the region, pDF-1, encoded a single transcribed region and contained the MALp gene. A 2nd subclone, p1, contained the MALg function but had not 1 but 2 maltose-inducible transcripts. Subclones having only 1 of these transcribed regions lacked MALg activity. The 3 transcribed regions were named MAL61 and MAL62, which correspond to MALg; and MAL63, which corresponds to MALp. This clustered arrangement of a regulatory gene adjacent to the sequences it controls has not previously been described in eukaryotes and its reminiscent of bacterial operons except that the messenger RNA molecules are not polycistronic.