The two fungal enzymes, C-14 sterol reductase (gene ERG24 in budding yeast and erg3 in Neurospora crassa) and C-24(28) sterol reductase (gene ERG4 in budding yeast and sts1 in fission yeast), are involved in ergosterol biosynthesis. They act by reducing double bonds in precursors of ergosterol [1]. These proteins are highly hydrophobic and seem to contain seven or eight transmembrane regions. Chicken lamin B receptor that is thought to anchor the lamina to the inner nuclear membrane belongs to this family.
Lai MH, Bard M, Pierson CA, Alexander JF, Goebl M, Carter GT, Kirsch DR.
The identification of a gene family in the Saccharomyces cerevisiae ergosterol biosynthesis pathway.
Gene 140 41-9 1994
[PubMed: 8125337] http://dx.doi.org/10.1016/0378-1119(94)90728-5