CLONING AND SEQUENCE OF THE SCS3 GENE WHICH IS REQUIRED FOR INOSITOL PROTOTROPHY IN SACCHAROMYCES-CEREVISIAE

The SCS3 gene of Saccharomyces cerevisiae was cloned by functional com plementation, using a conditional mutant exhibiting myo-inositol auxot rophy in the presence of choline, and sequenced. The sequence containe d an open reading frame capable of encoding 380 amino acids with a cal culated molecular weight of 42,734. Disruption of the SCS3 locus cause d myo-inositol auxotrophy. The gene appeared to be involved in the syn thesis of inositol phospholipids from inositol but not in the control of inositol synthesis.