Two FPP molecules dimerize to form presqualene diphosphate Authored: Jassal, B, 2007-01-24 15:15:12 EC Number: 2.5.1.21 Farnesyl diphosphate farnesyltransferase (FDFT; squalene synthase) catalyzes the reductive dimerization of two farnesyl diphosphate (FPP) molecules to form squalene. This happens in two distinct steps. The first step of dimerization forms presqualene diphosphate (Pandit et al. 2000). Pubmed10896663 Reactome Database ID Release 43191405 Reactome, http://www.reactome.org ReactomeREACT_9512 Reviewed: D'Eustachio, P, 2007-01-22 01:32:07 has a Stoichiometric coefficient of 2