Isoprenyl pyrophosphate synthases

The initial reactions of terpene biosynthesis are catalyzed by short-chain prenyltransferases belonging to the class of trans- or cis- isoprenyl pyrophosphate synthases that catalyze chain elongation of allylic pyrophosphate substrates with IPP to generate linear polymers with defined chain length. Geranyl pyrophosphate... 

The isoprenyl pyrophosphate synthases (IPPS) catalyse the formation of long-chain prenyl pyrophosphates by the addition of an aUylic cation generated from DMAPP, GPP or FPP to one or more molecules of IPP. Terpene synthases are responsible for the conversion of prenyl pyrophosphates into the classic terpene structures a large number of these are cyclic structures so these synthases are also known as terpene cyclases. Protein prenyltransferases catalyse the addition of isoprenoid chains to a protein or peptide. Here we consider mainly the first two of these. 

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