<p>The beta subunit of the farnesyltransferases is responsible for peptide binding.Squalene-hopene cyclase is a bacterial enzyme that catalyzes the cyclization of squalene into hopene, a key step in hopanoid (triterpenoid) metabolism [<cite idref="PUB00005227"/>]. Lanosterol synthase (<db_xref db="EC" dbkey="5.4.99.7"/>) (oxidosqualene-lanosterol cyclase) catalyzes the cyclization of (S)-2,3-epoxysqualene to lanosterol, the initial precursor of cholesterol, steroid hormones and vitamin D in vertebrates and of ergosterol in fungi [<cite idref="PUB00005416"/>]. Cycloartenol synthase (<db_xref db="EC" dbkey=" 5.4.99.8"/>) (2,3-epoxysqualene-cycloartenol cyclase) is a plant enzyme that catalyzes the cyclization of (S)-2,3-epoxysqualene to cycloartenol.</p> Prenyltransferase/squalene oxidase