KEGG Orthology (KO) [BR:ko00001]
09100 Metabolism
09108 Metabolism of cofactors and vitamins
00860 Porphyrin metabolism
K10960 chlP, bchP; geranylgeranyl diphosphate/geranylgeranyl-bacteriochlorophyllide a reductase
09109 Metabolism of terpenoids and polyketides
00900 Terpenoid backbone biosynthesis
K10960 chlP, bchP; geranylgeranyl diphosphate/geranylgeranyl-bacteriochlorophyllide a reductase
Enzymes [BR:ko01000]
1. Oxidoreductases
1.3 Acting on the CH-CH group of donors
1.3.1 With NAD+ or NADP+ as acceptor
1.3.1.83 geranylgeranyl diphosphate reductase
K10960 chlP, bchP; geranylgeranyl diphosphate/geranylgeranyl-bacteriochlorophyllide a reductase
1.3.1.111 geranylgeranyl-bacteriochlorophyllide a reductase
K10960 chlP, bchP; geranylgeranyl diphosphate/geranylgeranyl-bacteriochlorophyllide a reductase
Reduced activity of geranylgeranyl reductase leads to loss of chlorophyll and tocopherol and to partially geranylgeranylated chlorophyll in transgenic tobacco plants expressing antisense RNA for geranylgeranyl reductase
bacteriochlorophyll a [CPD:C11242];
NADP+ [CPD:C00006]
Product
geranylgeranyl bacteriochlorophyllide a [CPD:C21217];
NADPH [CPD:C00005];
H+ [CPD:C00080]
Comment
The enzyme catalyses the successive reduction of the geranylgeraniol esterifying group to phytol, reducing three out of four double bonds, and transforming geranylgeranyl bacteriochlorophyllide a via dihydrogeranylgeranyl bacteriochlorophyllide a and tetrahydrogeranylgeranyl bacteriochlorophyllide a to bacteriochlorophyll a. The enzyme can also accept the pheophytin derivative geranylgeranyl bacteriopheophytin, converting it to bacteriopheophytin a.
Molecular genetic analysis of terminal steps in bacteriochlorophyll a biosynthesis: characterization of a Rhodobacter capsulatus strain that synthesizes geranylgeraniol-esterified bacteriochlorophyll a.
Accumulation of chlorophyllous pigments esterified with the geranylgeranyl group and photosynthetic competence in the CT2256-deleted mutant of the green sulfur bacterium Chlorobium tepidum.