Transferases;
Transferring alkyl or aryl groups, other than methyl groups;
Transferring alkyl or aryl groups, other than methyl groups (only sub-subclass identified to date)
BRITE hierarchy

geranylgeranyl diphosphate:geranylgeranyl diphosphate geranylgeranyltransferase

2 geranylgeranyl diphosphate + NADPH + H+ = lycopaoctaene + 2 diphosphate + NADP+ (overall reaction) [RN:R12281];
(1a) 2 geranylgeranyl diphosphate = diphosphate + prephytoene diphosphate [RN:R02065];
(1b) prephytoene diphosphate + NADPH + H+ = lycopaoctaene + diphosphate + NADP+ [RN:R12280]

R02065 R12280 R12281
Reaction

geranylgeranyl diphosphate [CPD:C00353];
NADPH [CPD:C00005];
H+ [CPD:C00080];
prephytoene diphosphate [CPD:C03427]

The enzyme, characterized from the green microalga Botryococcus braunii race L, in involved in biosynthesis of (14E,18E)-lycopadiene. In vitro, the enzyme can accept (2E,6E)-farnesyl diphosphate and phytyl diphosphate as substrates, and is also able to catalyse the condensation of two different substrate molecules, forming chimeric products. However, the use of these alternative substrates is not significant in vivo.

EC 2.5.1.148 created 2018

1  [PMID:27050299]

Thapa HR, Naik MT, Okada S, Takada K, Molnar I, Xu Y, Devarenne TP

A squalene synthase-like enzyme initiates production of tetraterpenoid hydrocarbons in Botryococcus braunii Race L.

Nat Commun 7:11198 (2016)
DOI:10.1038/ncomms11198

[ag:AMV49169]

2  [PMID:28813599]

Thapa HR, Tang S, Sacchettini JC, Devarenne TP

Tetraterpene Synthase Substrate and Product Specificity in the Green Microalga Botryococcus braunii Race L.

ACS Chem Biol 12:2408-2416 (2017)
DOI:10.1021/acschembio.7b00457

[ag:AMV49169]