Reaction: 2 S-adenosyl-L-methionine + a bacteriochlorophyllide c + H2O = a bacteriochlorophyllide e + 2 5'-deoxyadenosine + 2 L-methionine (overall reaction)
(1a) S-adenosyl-L-methionine + a bacteriochlorophyllide c + H2O = a 7-(hydroxymethyl)bacteriochlorophyllide c + 5'-deoxyadenosine + L-methionine
(1b) S-adenosyl-L-methionine + a 7-(hydroxymethyl)bacteriochlorophyllide c + H2O = a 7-(dihydroxymethyl)bacteriochlorophyllide c + 5'-deoxyadenosine + L-methionine
(1c) a 7-(dihydroxymethyl)bacteriochlorophyllide c = a bacteriochlorophyllide e + H2O (spontaneous)
For diagram of reaction click here.
Other name(s): bciD (gene name)
Systematic name: bacteriochlorophyllide-c:S-adenosyl-L-methionine oxidoreductase (C-71-hydroxylating)
Comments: The enzyme, found in green sulfur bacteria (Chlorobiaceae), is a radical S-adenosyl-L-methionine (AdoMet) enzyme and contains a [4Fe-4S] cluster. It catalyses two consecutive hydroxylation reactions of the C-7 methyl group of bacteriochlorophyllide c to form a geminal diol intermediate that spontaneously dehydrates to produce the formyl group of bacteriochlorophyllide e.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. Harada, J., Mizoguchi, T., Satoh, S., Tsukatani, Y., Yokono, M., Noguchi, M., Tanaka, A. and Tamiaki, H. Specific gene bciD for C7-methyl oxidation in bacteriochlorophyll e biosynthesis of brown-colored green sulfur bacteria. PLoS One 8 (2013) e60026. [PMID: 23560066]
2. Thweatt, J.L., Ferlez, B.H., Golbeck, J.H. and Bryant, D.A. BciD is a radical S-adenosyl-L-methionine (SAM) enzyme that completes bacteriochlorophyllide e biosynthesis by oxidizing a methyl group into a formyl group at C-7. J. Biol. Chem. 292 (2017) 1361-1373. [PMID: 27994052]