InterPro: IPR018083 Sterol reductase, conserved site

The following enzymes belong to a conserved family of sterol reductases which act by reducing double bonds [1, 2]:

• Fungal delta(14)-sterol reductase (EC:1.3.1.70) (C-14 sterol reductase) (gene ERG24 in budding yeast), an enzyme of ergosterol biosynthesis.
• Mammalian (TM7SF2) and plant delta(14)-sterol reductases.
• Fungal delta(24(24(1)))-sterol reductase (EC:1.3.1.71) (C-24(28) sterol reductase) (gene ERG4 in budding yeast), an enzyme of ergosterol biosynthesis.
• Mammalian 7-dehydrocholesterol reductase (EC:1.3.1.21) which produces cholesterol by reduction of C7-C8 double bond of 7-dehydrocholesterol (7- DHC).
• Lamin B receptor, which is thought to anchor the lamina to the inner nuclear membrane.

All these proteins are highly hydrophobic and seem to contain seven or eight transmembrane regions.