Analysis and expression of the Candida albicans FAS2 gene.

Candida albicans (Ca) FAS2, the gene encoding the alpha-subunit of fatty acid synthase (FAS), has been isolated and characterized. Saccharomyces cerevisiae (Sc) FAS2 was used as a probe to screen genomic libraries of Ca, strain 4918. Clones were obtained that contained all but the first 1 kb of the gene. The 5' end, as well as upstream sequences, were subsequently isolated by PCR. The Ca FAS2 gene is comprised of an open reading frame (ORF) of 5655 bp that is free of introns and encodes a 207, 587-Da protein of 1885 amino acids. The Ca FAS2 gene and the encoded polypeptide exhibit 70 and 67% homology with the Sc FAS2 gene and protein, respectively. The gene specifies a single transcript of approx. 6 kb, and transcript levels are regulated independently of morphogenesis. Chromosome analysis localized the gene to chromosome 3. In addition, no differences were noted when comparing the FAS2 sequence, that encompasses the cerulenin-binding domain of FAS, between strain 4918 and two derived cerulenin-resistant (CerR) mutants. Thus, alteration within this region is not responsible for the increased CerR of the mutant strains.