Table 1.

Ergosterol biosynthetic pathway from squalene to ergosterola

Embedded Image
  • a The table lists the ERG gene designations, the enzyme encoded by the gene, a selected number of sterol intermediates, and the antifungal inhibitors that are directed at specific enzymes. Several sterol intermediates, side paths, and alternate pathways are not listed, for simplification. All of the genes listed have been cloned in S. cerevisiae (27,103) except ERGX and ERGY. The C-4 sterol demethylase enzymes include three enzyme activities which together remove two methyl groups from C-4 (two arrows). Two of the genes for the C-4 sterol demethylase enzymes, referred to as ERGX andERGY in the table, have not been cloned and do not yet have gene designations (103). The azole inhibition ofERG5 has recently been suggested (83).