Prenyltransferases (PTs) are a class of enzymes that transfer allylic prenyl groups to acceptor molecules.

[2][3] Prenyltransferases are a functional category and include several enzyme groups that are evolutionarily independent.

Prenyltransferases are commonly divided into two classes, cis (or Z) and trans (or E), depending upon the stereochemistry of the resulting products.

Cis-prenyltransferases include dehydrodolichol diphosphate synthase (involved in the production of a precursor to dolichol).

Squalene-hopene cyclase is a bacterial enzyme that catalyzes the cyclization of squalene into hopene, a key step in hopanoid (triterpenoid) metabolism.