DISRUPTION AND MAPPING OF IDI1, THE GENE FOR ISOPENTENYL DIPHOSPHATE ISOMERASE IN SACCHAROMYCES-CEREVISIAE

Isopentenyl diphosphate isomerase catalyses an essential activation step in the isoprene biosynthetic pathway. The Saccharomyces cerevisiae gene for isomerase, IDI1, was recently isolated and characterized (Anderson et al. J. Biol. Chem. 1989a, 264,19169-19175). Wild-type IDI1 was disrupted with a LEU2 marker, and the resulting DNA was used to transform a yeast leucine auxotroph. Southern blots of EcoRI fragments of chromosomal DNA from the diploid strain showed the expected fragments for intact and disrupted IDI1. Dissection and analysis of tetrads demonstrated that IDI1 is an essential single-copy gene. A CHEF gel and clone grid filter analysis, followed by chromosomal mapping indicated that the gene is located on chromosome XVI approximately 55 kb contromere proximal to PEP4.