View source for Trans,polycis-polyprenyl diphosphate synthase ((2Z,6E)-farnesyl diphosphate specific)

{{Infobox enzyme
| Name = All-trans-phytoene synthase
| EC_number = 2.5.1.99
| CAS_number = 
| IUBMB_EC_number = 2/5/1/99
| GO_code = 
| image = 
| width = 
| caption =
}}
'''All-trans-phytoene synthase''' ({{EC number|2.5.1.99}}, ''prephytoene-diphosphate synthase'', ''phytoene synthetase'', ''PSase'', ''geranylgeranyl-diphosphate geranylgeranyltransferase'', ''15-trans-phytoene synthase'') is an [[enzyme]] with system name ''geranylgeranyl-diphosphate:geranylgeranyl-diphosphate geranylgeranyltransferase (all-trans-phytoene forming)''.<ref>{{cite journal | title = 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 |author = Gregonis, D.E. and Rilling, H.C. |journal = Biochemistry |year = 1974 |volume = 13 |pages = 1538–1542 |pmid = 4819767 | doi = 10.1021/bi00704a033 | issue = 7}}</ref><ref>{{cite journal | title = Bacterial phytoene synthase: molecular cloning, expression, and characterization of ''Erwinia'' herbicola phytoene synthase |author = Iwata-Reuyl, D., Math, S.K., Desai, S.B. and Poulter, C.D. |journal = Biochemistry |year = 2003 |volume = 42 |pages = 3359–3365 |pmid = 12641468 | doi = 10.1021/bi0206614 | issue = 11}}</ref> This enzyme [[catalysis|catalyses]] the following [[chemical reaction]]

: 2 [[geranylgeranyl diphosphate]] <math>\rightleftharpoons</math> all-trans-phytoene + 2 [[diphosphate]] (overall reaction)
:(1a) 2 geranylgeranyl diphosphate <math>\rightleftharpoons</math> diphosphate + [[prephytoene diphosphate]]
:(1b) prephytoene diphosphate <math>\rightleftharpoons</math> all-trans-phytoene + diphosphate

This enzyme requires Mn<sup>2+</sup> for activity.

== References ==
{{reflist}}

== External links ==
*{{MeshName|All-trans-phytoene+synthase}}

[[Category:EC 2.5.1]]