Cloning and analysis of theKluyveromyces lactis TRP1gene: A chromosomal locus flanked by genes encoding inorganic pyrophosphatase and histone H3

摘要

AbstractTheTRP1gene of the yeastKluyveromyces lactishas been cloned from a genomic library by complementation of theSaccharomyces cerevisiae trpl‐289 mutation. The gene was located within the clone by transposon mutagenesis and the coding region identified by DNA sequencing. This has indicated thatK. lactis TRP1encodes a 210‐amino acid polypeptide which shows 53 identity to the homologousS. cerevisiaeprotein. TheK. lactis TRP1gene has been disrupted by substituting theS. cerevisiae URA3gene for a large part of theTRP1coding sequence. Replacement of the chromosomalTRP1locus with this construction has enabled the production of non‐revertingtrp1−strains ofK. lactis, while a genetic analysis of the disrupted allele confirmed that theTRP1gene had been cloned. DNA sequencing has also shown that theK. lactis TRP1sequences is flanked by genes encoding inorganic pyrophosphatase and histone H3, which we have designatedIPPandHHT1respectively. Hybridization studies have shown that in common withS. cerevisiae,K. lactishas two copies of the histone H3 gene. Each H3 gene is closely linked to a gene encoding histone H4 and in both yeast species theIPPgene is tightly linked to one of the histone gen