Sequence of the Candida albicans erg7 gene

Area of Science:

• Biochemistry
• Molecular Biology
• Genetics

Background:

• Ergosterol biosynthesis is crucial for fungal cell membrane integrity.
• The erg7 gene in Candida albicans is implicated in sterol production.
• Oxidosqualene cyclase activity is a key step in ergosterol pathway.

Purpose of the Study:

• To determine the nucleotide sequence of the Candida albicans erg7 gene.
• To confirm the function of the erg7 gene product as oxidosqualene cyclase.
• To provide molecular evidence for the erg7 gene's role in sterol biosynthesis.

Main Methods:

• Nucleotide sequencing of the Candida albicans erg7 gene.
• Complementation of Saccharomyces cerevisiae erg7 mutants.
• Assay of oxidosqualene cyclase activity.

Main Results:

• The nucleotide sequence of the Candida albicans erg7 gene was successfully determined.
• The erg7 gene complements erg7 mutants in Saccharomyces cerevisiae, restoring function.
• The encoded 728-amino acid protein shows homology to squalene-hopene cyclase.
• Restored oxidosqualene cyclase activity was observed in complemented mutants.

Conclusions:

• The erg7 gene encodes the 2,3-oxidosqualene cyclase in Candida albicans.
• The protein product of erg7 shares homology with other cyclase enzymes.
• This study provides strong molecular evidence for the identity and function of the erg7 gene.