Cloning of a Candida utilis gene which complements leu2 mutation in Saccharomyces cerevisiae

DNA fragments containing the LEU2 gene of Candida utilis have been isolated, utilizing the genome library (constructed in YRp12) of this organism. Two recombinant plasmids pZR84 and pZR32, containing the cloned LEU2 gene, were 4.24 kb and 10.4 kb, respectively, and were shown to complement leu2 mutation in Saccharomyces cerevisiae and leuB mutation in Escherichia coli. The cloned fragment in pZR84 contained one restriction site each for EcoRI and PvuII, and two for HindIII, but none for SalI, BamHI or PstI. This cloned fragment hybridized with the total DNA from C. utilis and from Leu+ transformants of S. cerevisiae, but not with that from untransformed S. cerevisiae. Subcloning analyses showed that a 2.34 kb BamHI-HindIII fragment of the cloned C. utilis sequence contains the region essential for the expression of the LEU2 gene.