IUBMB Enzyme Nomenclature


Accepted name: 15-cis-phytoene synthase

Reaction: 2 geranylgeranyl diphosphate = 15-cis-phytoene + 2 diphosphate (overall reaction)
(1a) 2 geranylgeranyl diphosphate = diphosphate + prephytoene diphosphate
(1b) prephytoene diphosphate = 15-cis-phytoene + diphosphate

For diagram of reaction click here

Other name(s): prephytoene-diphosphate synthase (ambiguous); phytoene synthetase (ambiguous); PSase (ambiguous); geranylgeranyl-diphosphate geranylgeranyltransferase (ambiguous)

Systematic name: geranylgeranyl-diphosphate:geranylgeranyl-diphosphate geranylgeranyltransferase (15-cis-phytoene forming)

Comments: Requires Mn2+ for activity. The enzyme produces 15-cis-phytoene. cf. EC, 15-trans-phytoene synthase.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 50936-61-3


1. Gregonis, D.E. and Rilling, H.C. 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 (1974) 1538-1542. [PMID: 4819767]

2. Misawa, N., Truesdale, M.R., Sandmann, G., Fraser, P.D., Bird, C., Schuch, W. and Bramley, P.M. 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. J. Biochem. (Tokyo) 116 (1994) 980-985. [PMID: 7896759]

[EC created 1984, modified 2005, modified 2012]

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