Biochemistry and Molecular Biology of Sterol Synthesis in Saccharomyces cerevisiae

This chapter explores the biochemical events of ergosterol biosynthesis as well as review the cloning and characterization of the genes that code for the pathway enzymes. The availability of a well-characterized genetic system and the ease of isolating mutants in a haploid organism have made yeast a major source of information on the biochemistry and molecular biology of sterol biosynthesis. Modern techniques in molecular biology have been used to identify the sterol features essential for viability, and information on this pathway has also been important in the characterization and development of compounds that have antifungal activity. The morpholines inhibit two different steps in sterol synthesis and have been employed primarily as agricultural fungicides, although one compound, amorolfine, is available in topical form for use against dermatophytic infections. The polyisoprenoid dolichols, glycosyl carrier lipids functioning in glycolipid synthesis, are derived from farnesyl pyrophosphate, a sterol pathway intermediate.