CHARACTERIZATION OF SFP2, A PUTATIVE SULFATE PERMEASE GENE OF SACCHAROMYCES-CEREVISIAE

The SFP2 gene of Saccharomyces cerevisiae has been characterized. The deduced amino acid sequence contained twelve highly hydrophobic domain s and showed 50, 47, 44 and 48% homologies to Neurospora crassa sulfat e permease II (CYS14), soybean GMAK170 nodulin, human colon mucosa pro tein (DRA) and a putative open reading frame (ORF) downstream of Esche richia coli prs (phosphoribosyl pyrophosphatate synthetase) gene, resp ectively, in the aligned regions. Cells lacking SFP2 were viable and d isplayed no obvious decrease in their growth rate. Southern blot analy sis revealed that SFP2 exists as a single copy in haploid genome. Nort hern blot analysis showed that SFP2 produced a 2.8-kb transcript which was highly expressed under sulfur derepressing condition. SFP2 mRNA w as found to turn over with a half-life of approximately 15 min, which may contribute to the regulation of sulfate permease function, and rea ched its maximal level in about 22 h after derepression. (C) 1995 Acad emic Press, Inc.