MOLECULAR-CLONING AND SEQUENCING OF THE HCS GENE, WHICH ENCODES 3-HYDROXY-3-METHYLGLUTARYL COENZYME-A SYNTHASE OF SCHIZOSACCHAROMYCES-POMBE

We have cloned and sequenced the hcs gene, which is thought to encode a 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) synthase consisting of 447 amino acids, from the fission yeast Schizosaccharomyces pombe. The predicted amino acid sequence of the hcs product of S. pombe has h omology with the HMG-CoA synthase of rat (47.8%), chicken (49.2%), ham ster (47.1%) and human cells (46.9%). One of the hcs genes was replace d with a marker gene in the diploid cell. No viable hcs-disrupted hapl oid was isolated after tetrad dissection, suggesting that the hcs gene is essential for growth. However the hcs-defective mutant could be gr own on a medium containing 5 mg/ml mevalonate. These results strongly support that the hcs gene encodes HMG-CoA synthase and S. pombe contai ns a single copy of the hcs gene. The sequence of the hcs gene has bee n entered into the public data libraries under Accession Number U32187 .