In molecular biology, this protein domain belongs to the terpene synthase family (TPS).

In particular, the N terminal domain has feature of the copalyl diphosphate synthase (CPS) active site.

[1] The N-terminal domain forms an alpha-barrel similar to that of the sesquiterpene cyclase epiaristolochene synthase.

[2] Sequences containing this protein domain belong to the terpene synthase family.

It has been suggested that this gene family be designated tps (for terpene synthase).