Isolation and Nucleotide Sequence of Hansenula anomala URA3 Gene Encoding Orotidine-5'-Phosphate Decarboxylase

Abstract The URA3 gene, encoding orotidine-5′-phosphate decarboxylase, was isolated from a Hansenula anomata genomic library by hybridization with the Saccharomyces cerevisiae URA3 gene. The nucleotide sequence and the transcriptional starting points were determined. An open reading frame of the gene corresponded to a protein composed of 268 amino acids, which showed homology to the orotidine-5′-phosphate decarboxylase (ODCase) of other yeast species. The ODCase of H. anomala is most closely related to those of the budding yeasts, Kluyveromyces lactis and S. cerevisiae (81% and 73% homology, respectively). The H. anomala URA3 gene complemented the ura3 mutation of S. cerevisiae . The 5′ and 3′ flanking sequences were different from those of the URA3 genes of S. cerevisiae and other yeasts. The sequences TAG—TA(T)GT—TTT, polyadenylation sites in the S. cerevisiae gene, were also found in the H. anomala URA3 gene.