SUC1 gene of Saccharomyces: a structural gene for the large (glycoprotein) and small (carbohydrate-free) forms of invertase.
Saccharomyces cerevisiae revertant strain D10-ER1 has been shown to contain thermosensitive forms of the large (glycoprotein) and small (carbohydrate-free) invertases and a very low level of the small enzyme, along with a wild-type level of the large form (T. Mizunaga et al., Mol. Cell. Biol. 1:460-468, 1981). These characteristics cosegregated in crosses of the revertant strain with wild-type sucrose-fermenting (SUC1) or nonfermenting (suc0) strains. In addition, there is tight linkage between sucrose and maltose fermentation in revertant D10-ER1 (characteristic of the SUC1 and MAL1 genes). From this we infer that a single reversion event is responsible for the several changes observed in D10-ER1, and that this mutation maps within or very close to the SUC1 gene present in the ancestor strain 4059-358D. The revertant SUC1 allele in D10-ER1 (termed SUC1-R1) was expressed independently of the wild-type SUC1 gene when both were present in diploid cells. Diploids carrying only the wild-type or the mutant genes synthesized invertases with the characteristics of the parental Suc+ haploids. The possibility that a modifier gene was responsible for the alterations in the invertases of revertant D10-ER1 was ruled out by appropriate crosses. We conclude that SUC1 is a structural gene that codes for both the large and the small forms of invertase and suggest that SUC2 through SUC5 are structural genes as well.
D000483:Alleles; D003433:Crosses, Genetic; D005796:Genes; D005800:Genes, Fungal; D006023:Glycoproteins / Q000235:genetics; D006026:Glycoside Hydrolases / Q000235:genetics*; D008320:Maltose / Q000378:metabolism; D009154:Mutation; D010641:Phenotype; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism; D013395:Sucrose / Q000378:metabolism; D013696:Temperature; D043324:beta-Fructofuranosidase
D006023:Glycoproteins; D013395:Sucrose; D008320:Maltose; D006026:Glycoside Hydrolases; D043324:beta-Fructofuranosidase