The nucleotide sequence of the Candida albicans ADE2 gene, which encodes phosphoribosylaminoimidazole carboxylase, has been determined. The sequence possesses an uninterrupted open reading frame of 1704 nucleotides corresponding to 568 amino acid residues. The deduced amino acid sequence shares a high degree of homology with ADE2 homologues in other fungal species including Saccharomyces cerevisiae, Pichia methanolica, Schwanniomyces occidentalis and Schizosaccharomyces pombe. Three regions of amino acid sequence were highly conserved among all reported ADE2 genes. The hexanucleotide TGACTC characteristic of genes involved in purine and amino acid biosynthesis is located in front of putative TATA boxes in the promoter region.