farnesylpyrophosphatesyntase

Farnesylpyrophosphate synthase, also known as farnesyl diphosphate synthase or FPP synthase, is an enzyme that catalyzes the synthesis of farnesyl pyrophosphate (FPP). This enzyme plays a crucial role in the isoprenoid biosynthesis pathway, also known as the mevalonate pathway. FPP is a key intermediate in the production of a vast array of biologically important molecules.

The reaction catalyzed by farnesylpyrophosphate synthase involves the sequential condensation of two molecules of isopentenyl pyrophosphate (IPP) with one molecule of dimethylallyl pyrophosphate (DMAPP). IPP and DMAPP are themselves five-carbon units. The initial condensation of DMAPP and IPP yields geranyl pyrophosphate (GPP), a ten-carbon molecule. A second molecule of IPP then condenses with GPP to form FPP, which is a fifteen-carbon isoprenoid. This enzyme is a member of the prenyltransferase family.

Farnesyl pyrophosphate synthase is essential for the synthesis of various compounds, including steroids, carotenoids, ubiquinones, and dolichols. In humans and other eukaryotes, FPP is a precursor for cholesterol synthesis, a vital component of cell membranes and a precursor for steroid hormones. In plants, FPP is a precursor for compounds like carotenoids, which are pigments involved in photosynthesis, and gibberellins, which are plant hormones. In fungi, FPP is used to produce ergosterol, the main sterol in fungal cell membranes. Due to its central role, farnesylpyrophosphate synthase is a target for therapeutic interventions, particularly in the development of cholesterol-lowering drugs and anti-cancer agents.