title: Genetic control of invertase formation in Saccharomyces cerevisiae. II. Isolation and characterization of mutants conferring invertase hyperproduction in strain EK-6B carrying the SUC3 gene.
abstract: Invertase formation in the yeast Saccharomyces cerevisiae is subject to repression by hexoses in the growth medium. Mutagen-induced (ethyl methanesulfonate or N-methyl-N-nitro-nitrosoguanidine) invertase hyperproducer mutants have been derived from the SUC3 MAL3 strain EK-6B by selecting for their ability to grow on media containing the sugar raffinose plus 2-deoxy-D-glucose (2DG). Raffinose like sucrose is a betta-fructoside which can be hydrolyzed by yeast invertase (beta-fructoside which can be hydrolyzed by yeast invertase (beta-fructofuranoside fructohydrolase). These mutants, designated dgr, produce higher levels of invertase (pi-glucosidase levels are also elevated but to a lesser extent) under conditions normally repressing invertase biosynthesis in the parent. Invertases of mutants dgr2 and dgr3 are indistinguishable from that of EK-6B with respect to their Km's for sucrose and thermal labilities. Genetic studies revealed that dgr2 and dgr3 are recessive and unlinked to the SUC3 gene.
mesh_terms: D004790:Enzyme Induction; D005020:Ethyl Methanesulfonate / Q000494:pharmacology; D005796:Genes; D005808:Genes, Recessive; D008040:Genetic Linkage; D008769:Methylnitronitrosoguanidine / Q000494:pharmacology; D009153:Mutagens; D009154:Mutation; D011887:Raffinose / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D013393:Sucrase / Q000096:biosynthesis / Q000235:genetics*; D013395:Sucrose / Q000378:metabolism
chemical_list: D009153:Mutagens; D008769:Methylnitronitrosoguanidine; D013395:Sucrose; D005020:Ethyl Methanesulfonate; D013393:Sucrase; D011887:Raffinose