Accepted name: geranylgeranyl-bacteriochlorophyllide a reductase
Reaction: bacteriochlorophyll a + 3 NADP+ = geranylgeranyl bacteriochlorophyllide a + 3 NADPH + 3 H+
Other name(s): geranylgeranyl-bacteriopheophytin reductase; bchP (gene name)
Systematic name: bacteriochlorophyll-a:NADP+ oxidoreductase (geranylgeranyl-reducing)
Comments: 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.
1.  Bollivar, D.W., Wang, S., Allen, J.P. and Bauer, C.E. Molecular genetic analysis of terminal steps in bacteriochlorophyll a biosynthesis: characterization of a Rhodobacter capsulatus strain that synthesizes geranylgeraniol-esterified bacteriochlorophyll a. Biochemistry 33 (1994) 12763–12768. [PMID: 7947681]
2.  Addlesee, H.A. and Hunter, C.N. Physical mapping and functional assignment of the geranylgeranyl-bacteriochlorophyll reductase gene, bchP, of Rhodobacter sphaeroides. J. Bacteriol. 181 (1999) 7248–7255. [PMID: 10572128]
3.  Addlesee, H.A. and Hunter, C.N. Rhodospirillum rubrum possesses a variant of the bchP gene, encoding geranylgeranyl-bacteriopheophytin reductase. J. Bacteriol. 184 (2002) 1578–1586. [PMID: 11872709]
4.  Harada, J., Miyago, S., Mizoguchi, T., Azai, C., Inoue, K., Tamiaki, H. and Oh-oka, H. Accumulation of chlorophyllous pigments esterified with the geranylgeranyl group and photosynthetic competence in the CT2256-deleted mutant of the green sulfur bacterium Chlorobium tepidum. Photochem Photobiol Sci 7 (2008) 1179–1187. [PMID: 18846281]
[EC created 2016]