catalytic activity:3-beta-hydroxy-4-beta-methyl-5-alpha-cholest-7-ene-4-alpha-carbaldehyde + NAD(P)H + O(2) = 3-beta-hydroxy-4-beta-methyl-5-alpha-cholest-7-ene-4-alpha-carboxylate + NAD(P)(+) + H(2)O.,catalytic activity:4,4-dimethyl-5-alpha-cholest-7-en-3-beta-ol + NAD(P)H + O(2) = 4-beta-hydroxymethyl-4-alpha-methyl-5-alpha-cholest-7-en-3-beta-ol + NAD(P)(+) + H(2)O.,catalytic activity:4-beta-hydroxymethyl-4-alpha-methyl-5-alpha-cholest-7-en-3-beta-ol + NAD(P)H + O(2) = 3-beta-hydroxy-4-beta-methyl-5-alpha-cholest-7-ene-4-alpha-carbaldehyde + NAD(P)(+) + 2 H(2)O.,cofactor:Iron.,domain:The histidine box domains may contain the active site and/or be involved in metal ion binding.,pathway:Steroid biosynthesis; zymosterol biosynthesis; zymosterol from lanosterol: step 3/6.,similarity:Belongs to the sterol desaturase family.,
Endoplasmic reticulum membrane ; Multi-pass membrane protein .