Disruption of six ORFs on Saccharomyces cerevisiae chromosome X: the YJL069c gene of unknown function is essential to cell viability

The short flanking homology PCR strategy (Wach et at, 1994) was used to dis rupt six open reading frames (ORFs) on chromosome X of diploid strains (FY1 679 and W303) of the yeast Saccharomyces cerevisiae. Two of the six ORFs an alysed (YJL069c and YJL066c) display no similarity to known sequences. Thre e others( YJL065c, YJL068c, and YJL070c) are similar to those respectively encoding the DNA polymerase epsilon subunit c, human esterase D and rat AMP deaminase 1. YJL071w has recently been identified as the ARG2 gene coding for acetylglutamate synthase. Inactivation of the YJL069c gene proved letha l and the yjl071w haploid disruptants were auxotrophic for arginine. For th e four other gene inactivations, neither the heterozygous deletion diploids nor the corresponding haploid deletion mutants displayed any special pheno type when grown on rich glycerol or glucose medium or on synthetic minimal medium at three different temperatures, or on media containing compounds in terfering with nucleic acid or protein synthesis. Mating and sporulation ef ficiencies were the same for the viable disruptants as for wild-type cells. The six kanM X4 disruption cassettes were cloned into the pUG7 vector and each of the cognate wild-type genes was inserted into the pRS416 centromeri c plasmid. All strains and plasmids have been deposited in the EUROFAN coll ection (EUROSCARF, K.-D. Entian, Frankfurt, Germany). Copyright (C) 1999 Jo hn Wiley & Sons, Ltd.