In enzymology, a phosphoglycerol geranylgeranyltransferase () is an enzyme that catalyzes the chemical reaction geranylgeranyl diphosphate + sn-glyceryl 1-phosphate diphosphate + sn-3-O-(geranylgeranyl)glyceryl 1-phosphate Thus, the two substrates of this enzyme are geranylgeranyl diphosphate and sn-glyceryl 1-phosphate, whereas its two products are diphosphate and sn-3-O-(geranylgeranyl)glyceryl 1-phosphate. This enzyme belongs to the family of transferases, specifically those transferring aryl or alkyl groups other than methyl groups. The systematic name of this enzyme class is geranylgeranyl diphosphate:sn-glyceryl phosphate geranylgeranyltransferase. Other names in common use include glycerol phosphate geranylgeranyltransferase, geranylgeranyl-transferase, and prenyltransferase. References EC 2.5.1 Enzymes of unknown structure