Isolation and characterization of a beta-tubulin gene from Candida albicans

We report the isolation and nucleotide sequence determination of a beta-tubulin gene (TUB2) from the pathogenic dimorphic fungus Candida albicans. Nucleotide sequence analysis revealed that TUB2 encodes a protein of 449 amino acids (aa) with considerable sequence homology to beta-tubulins isolated from other fungal species. The nucleotide sequence of the C. albicans gene is 70% homologous to that of the Saccharomyces cerevisiae gene. The coding region for the C. albicans beta-tubulin gene is interrupted by two introns. The first intron occurs after the 4th aa and the second intron occurs after the 13th aa. A comparison with other fungal beta-tubulin genes indicates that the intron locations are highly conserved. Codon usage in the C. albicans TUB2 gene is nonrandom, as has been observed for other fungal beta-tubulin genes. The C. albicans TUB2 gene is transcribed to yield a 1.8-kb mRNA species. On the basis of genomic Southern-blot analysis, we conclude that C. albicans most likely possesses a single beta-tubulin gene.