CLONING AND HETEROLOGOUS EXPRESSION OF THE CANDIDA-ALBICANS GENE PMI-1 ENCODING PHOSPHOMANNOSE ISOMERASE

Using a DNA fragment derived from the Saccharomyces cerevisiae phospho mannose isomerase (PMI) structural gene as a probe against a random or dered array library of genomic DNA from the pathogenic fungus Candida albicans, we have cloned the C. albicans PMI1 gene. This gene, which i s unique in the C. albicans genome, can functionally complement PMI-de ficient mutants of both S. cerevisiae and Escherichia cell. The DNA se quence of the PMI1 gene predicts a protein with 64.1% identity to PMI from S. cerevisiae. Sequential gene disruption of PIMI1 produces a str ain with an auxotrophic requirement for D-mannose. The heterologous ex pression of the PMI1 gene at levels up to 45% of total cell protein in E. coli leads to partitioning of the enzyme between the soluble and p articulate fractions. The protein produced in the soluble fraction is indistinguishable in kinetic properties from the material isolated fro m C. albicans cells. The nucleotide sequence data reported here will a ppear in the EMBL database under Accession Number X82024.