Phytoene synthase

Phytoene synthase (EC 2.5.1.32, prephytoene-diphosphate synthase, 15-cis-phytoene synthase, PSase, geranylgeranyl-diphosphate geranylgeranyltransferase) is a transferase enzyme involved in the biosynthesis of carotenoids. It catalyzes the conversion of geranylgeranyl pyrophosphate to phytoene.^[1][2][3][4] This enzyme catalyses the following chemical reaction

2 geranylgeranyl diphosphate ${\displaystyle \rightleftharpoons }$ 15-cis-phytoene + 2 diphosphate (overall reaction)

(1a) 2 geranylgeranyl diphosphate ${\displaystyle \rightleftharpoons }$ diphosphate + prephytoene diphosphate

(1b) prephytoene diphosphate ${\displaystyle \rightleftharpoons }$ 15-cis-phytoene + diphosphate

15-cis-phytoene synthase
Identifiers
EC no.	2.5.1.32
CAS no.	50936-61-3
Databases
IntEnz	IntEnz view
BRENDA	BRENDA entry
ExPASy	NiceZyme view
KEGG	KEGG entry
MetaCyc	metabolic pathway
PRIAM	profile
PDB structures	RCSB PDB PDBe PDBsum
Search PMC articles PubMed articles NCBI proteins

This enzyme requires Mn²⁺ for activity. It belongs to squalene/phytoene synthase family of proteins.