This invention relates to polynucleotides, polypeptides encoded by these polynucleotides, to the production of such polynucleotides and polypeptides, and to the uses of such polynucleotides and polypeptides. More specifically, the invention relates to the phosphomevalonate kinase (PMK) gene (ERG8 gene) from Candida Albicans (C. albicans), to methods for its expression yielding phosphomevalonate kinase protein, to hybrid organisms for use in such expression methods, to methods for purification of the protein, to methods and tools for diagnosing C. albicans infection and to assays for identifying inhibitors of the enzyme which inhibitors have potential as anti-fungal agents.