Phytoene synthase

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

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

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

References

1. Phytoene synthase
2. Gregonis DE, Rilling HC (March 1974). "The stereochemistry of trans-phytoene synthesis. Some observations on lycopersene as a carotene precursor and a mechanism for the synthesis of cis- and trans-phytoene". Biochemistry. 13 (7): 1538–42. doi:10.1021/bi00704a033. PMID   4819767.
3. Chamovitz, Daniel; Misawa, Norihiko; Sandmann, Gerhard; Hirschberg, Joseph (27 January 1992). "Molecular cloning and expression in of a cyanobacterial gene coding for phytoene synthase, a carotenoid biosynthesis enzyme". FEBS Letters. 296 (3): 305–310. doi:10.1016/0014-5793(92)80310-d. PMID   1537409.
4. Misawa N, Truesdale MR, Sandmann G, Fraser PD, Bird C, Schuch W, Bramley PM (November 1994). "Expression of a tomato cDNA coding for phytoene synthase in Escherichia coli, phytoene formation in vivo and in vitro, and functional analysis of the various truncated gene products". Journal of Biochemistry. 116 (5): 980–5. doi: 10.1093/oxfordjournals.jbchem.a124656 . PMID   7896759.