Isolation and Nucleotide Sequence Analysis of the URA3 (orotidine 5′-phosphate decarboxylase) Gene of Kluyveromyces lactis

Abstract

A gene complementing a ura3 mutation in Saccharomyces cerevisiae was isolated from Kluyveromyces lactis. Its nucleotide sequence showed an open reading frame of 801 bp, corresponding to 267 amino acid residues. These are homologous to the coding region of URA3 gene of S. cerevisiae, 71% and 82% at the nucleotide and the amino acid levels, respectively. Although transcription started at – 30 to – 40 from the initiation codon ATG, which is comparable to S. cerevisiae, the regulatory sequences identified in the 5' flanking regions of URA1 and URA3 genes of S. cerevisiae are not found in the URA3 gene of K. lactis.