The mating-type region of Schizosaccharomyces pombe h(-S) 972: sequencing and analysis of 69 kb including the expressed mat1 locus.

The sequence has been determined of 68 897 bp of genomic DNA including the expressed mat1 mating-type locus from Schizosaccharomyces pombe h(-S) strain 972. The DNA sequence, located on the long arm of fission yeast chromosome II and contained in two cosmid clones, was analysed to reveal one autonomously replicating sequence, two retrotransposon long terminal repeats (LTRs), one tRNA(Gly) gene and 33 open reading frames (ORFs), of which 15 contain introns. Nine of these ORFs code for previously described genes (trt1, rpl10, rps21, nif1, sui1 (psu1), matMi, matMc, let1 and rpa4), one of which (trt1) contains 15 introns, the highest number yet recorded in a gene of S. pombe. Of the remaining 24 ORFs, sequence similarity suggests that the function of 13 of the encoded proteins may be predicted and these include four mitochondrial proteins, two transport proteins, two signalling molecules, a component of serine palmitolytransferase, a homologue of 3-methyladenine DNA glycosylase, a multifunctional alcohol dehydrogenase, a killer toxin sensitivity factor and an acetyl transferase. Six deduced sequences appear to be related to proteins of unknown function in Saccharomyces cerevisiae or S. pombe and the remaining five are hypothetical proteins.