[Mutation of ade13-1 of the yeast Saccharomyces cerevisiae leads to the absence of growth on a complete medium with glucose and epistatically interacts with mutations in other genes for purine biosynthesis].

Saccharomyces cerevisiae gene ADE13 encodes enzyme adenylosuccinate lyase catalyzing steps 8 and 12 of the de novo purine pathway. The mutation ade13-1 induced by ethyl methanesulfonate leads to a complete loss of enzymatic activity. Stocks with this mutation cannot grow on complete organic media with glucose or fructose as a carbon source, but they can grow on media with glycerol or ethanol. The inhibiting effect of glucose is confirmed by the lack of growth on the medium with glycerol instead of glucose. Three independently obtained ade2 mutations and mutations ade1-p3, ade4, ade5, and ade5,7-33 suppress growth inhibition by glucose; i.e., they are epistatic with respect to this phenotypical expression of mutation ade13-1. The activity of adenylsuccinate lyase is not reconstituted. Mutations ade1-263, ade6, ade7-23, and ade8-21 do not manifest an epistatic effect. It was suggested that purine synthesis genes participate in the control of glycolysis or in the transduction of signal about the carbon source in the medium. The properties of ade mutations found by us were previously unknown. The results of our study contribute to the knowledge about the function of purine synthesis genes in yeasts.