ERG1, ENCODING SQUALENE EPOXIDASE, IS LOCATED ON THE RIGHT ARM OF CHROMOSOME-VII OF SACCHAROMYCES-CEREVISIAE

The ERG1 gene of Saccharomyces cerevisiae encodes squalene epoxidase, a key enzyme in the ergosterol pathway. ERG1 is an essential gene. Dis ruption of the gene with URA3 results in a lethal phenotype when cells are grown under aerobic conditions, even in the presence of ergostero l. However, cells are viable in the presence of ergosterol under anaer obic growth conditions during which ergosterol is taken up by cells. P hysical and genetic mapping data reveal that ERG1 is located on the ri ght arm of chromosome VII proximal to QCR9 at a distance of 14.6 cM fr om ADE3.