SEQUENCING AND ANALYSIS OF A 35.4 KB REGION ON THE LEFT ARM OF CHROMOSOME-IV FROM SACCHAROMYCES-CEREVISIAE REVEAL 23 OPEN READING FRAMES

The complete DNA sequence of cosmid clone 31A5 containing a 35 452 bp segment from the left arm of chromosome IV from Saccharomyces cerevisi ae, was determined from an ordered set of subclones in combination wit h primer walking on the cosmid. The sequence contains 23 open reading frames (ORFs) of more than 100 amino acid residues and the tRNA-Val2a gene. Five ORFs corresponded to the known yeast genes SNQ2, SES1, GCV1 , RPL2B and RPS18A. The DNA sequence for RPS18A is interrupted by an i ntron. One ORF corresponded td-a part of the yeast gene HEM at the end of the cosmid insert. Four ORFs encoded putative proteins which showe d strong homologies to other previously known proteins, three of yeast origin and one of non-yeast origin. Two ORFs were classified as havin g borderline homologies: one had similarity to two protein families an d another to two protein products of unknown function from other speci es. The remaining 11 ORFs bore no significant similarity to any publis hed protein. The complete DNA sequence has been submitted to the EMBL data library, Accession Number X95966.