GGPP synthase

GGPP synthase
	Ribbon model of the hexamer with GGPP as calottes according to PDB 2Q80
	Existing structural data : 2Q80
Properties of human protein
Mass / length primary structure	300 amino acids
Secondary to quaternary structure	Homohexamer (3 * dimer)
Cofactor	3 Mg 2+
Identifier
Gene name	GGPS1
External IDs	OMIM : 606982 ; UniProt : O95749 ;
Enzyme Classifications
EC, category	2.5.1.1 , transferase
Response type	Transfer of a prenyl residue
Substrate	DMAPP + IPP
Products	Geranyl diphosphate + PP i
EC, category	2.5.1.10 , transferase
Response type	Transfer of a geranyl residue
Substrate	Geranyl diphosphate + IPP
Products	Farnesyl diphosphate + PP i
EC, category	2.5.1.29 , transferase
Response type	Transfer of a farnesyl residue
Substrate	Farnesyl diphosphate + IPP
Products	GGPP + PP i
Occurrence
Parent taxon	Creature

GGPP synthetase (GGPPSase) is the enzyme in animals , comprising the condensation reaction of several isopentenyl diphosphate (IPP) molecules together with dimethylallyl diphosphate (DMAPP) to farnesyl diphosphate catalyzed , two steps in the biosynthesis of cholesterol . Another step to geranylgeranyl diphosphate (GGPP) is possible; GGPP participates in the post-translational modification of proteins and plays a role in cell apoptosis . In humans, GGPPSase is found in all tissue types, but is expressed in particularly large amounts in the testes .

Catalyzed reactions

+ ⇔ + PP _i

Isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP) condense to geranyl diphosphate.

+ ⇔
⇔ + PP _i

Isopentenyl diphosphate (IPP) and geranyl diphosphate condense to form farnesyl diphosphate.

Wikibooks: Biochemistry and Pathobiochemistry: Cholesterol Biosynthesis - Learning and Teaching Materials