501. An oligopeptide transport gene from Candida albicans.
- Author
-
Lubkowitz MA, Hauser L, Breslav M, Naider F, and Becker JM
- Subjects
- Amino Acid Sequence, Antifungal Agents pharmacology, Base Sequence, Biological Transport, Candida albicans drug effects, Candida albicans metabolism, Carrier Proteins metabolism, Cloning, Molecular, Ethionine pharmacology, Molecular Sequence Data, Oligopeptides pharmacology, Recombinant Proteins metabolism, Saccharomyces cerevisiae genetics, Saccharomyces cerevisiae metabolism, Sequence Analysis, DNA, Sequence Homology, Amino Acid, Transformation, Genetic, Candida albicans genetics, Carrier Proteins genetics, Fungal Proteins genetics, Genes, Fungal, Membrane Transport Proteins, Oligopeptides metabolism
- Abstract
A Candida albicans oligopeptide transport gene, OPT1, was cloned from a C. albicans genomic library through heterologous expression in the Saccharomyces cerevisiae di-/tripeptide transport mutant PB1X-9B. When transformed with a plasmid harbouring OPT1, S. cerevisiae PB1X-9B, which did not express tetra-/pentapeptide transport activity under the conditions used, was conferred with an oligopeptide transport phenotype, as indicated by growth on the tetrapeptide Lys-Leu-Leu-Gly, sensitivity to toxic tetra- and pentapeptides, and an increase in the initial uptake rate of the radiolabelled tetrapeptide Lys-Leu-Gly-[3H]Leu. The level of oligopeptide transport was found to be influenced in the heterologous host by the source of nitrogen used for growth. The entire 3.8 kb fragment containing the oligopeptide transport activity was sequenced and an ORF of 2349 nucleotides containing a 58 nucleotide intron was identified. The deduced protein product of 783 amino acid residues contained 12 hydrophobic regions suggestive of a membrane transport protein. Sequence comparisons revealed that similar proteins are encoded by genes from S. cerevisiae and Schizosaccharomyces pombe and that OPT1 is not a member of the ABC or PTR membrane transport families.
- Published
- 1997
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