IUBMB Enzyme Nomenclature


Accepted name: chlorophyllide a reductase

Reaction: (1) 3-deacetyl-3-vinylbacteriochlorophyllide a + 2 oxidized ferredoxin [iron-sulfur] cluster + ADP + phosphate = chlorophyllide a + 2 reduced ferredoxin [iron-sulfur] cluster + ATP + H2O + 2 H+
(2) bacteriochlorophyllide a + 2 oxidized ferredoxin [iron-sulfur] cluster + ADP + phosphate = 3-acetyl-3-devinylchlorophyllide a + 2 reduced ferredoxin [iron-sulfur] cluster + ATP + H2O + 2 H+
(3) 3-deacetyl-3-(1-hydroxyethyl)bacteriochlorophyllide a + 2 oxidized ferredoxin [iron-sulfur] cluster + ADP + phosphate = 3-devinyl-3-(1-hydroxyethyl)chlorophyllide a + 2 reduced ferredoxin [iron-sulfur] cluster + ATP + H2O + 2 H+

For diagram of reaction click here.

Other name(s): bchX (gene name); bchY (gene name); bchZ (gene name); COR

Systematic name: bacteriochlorophyllide-a:ferredoxin 7,8-oxidoreductase

Comments: The enzyme, together with EC, bacteriochlorophyllide-a dehydrogenase, and EC, chlorophyllide-a 31-hydratase, is involved in the conversion of chlorophyllide a to bacteriochlorophyllide a. These enzymes can act in multiple orders, resulting in the formation of different intermediates, but the final product of the cumulative action of the three enzymes is always bacteriochlorophyllide a. This enzyme catalyses a trans-reduction of the B-ring; the product has the (7R,8R)-configuration. In addition, the enzyme has a latent activity of EC, 3,8-divinyl protochlorophyllide a 8-vinyl-reductase (ferredoxin) [4]. The enzyme contains a [4Fe-4S] cluster, and structurally resembles the Fe protein/MoFe protein complex of nitrogenase (EC, which catalyses an ATP-driven reduction.

Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:


1. Nomata, J., Mizoguchi, T., Tamiaki, H. and Fujita, Y. A second nitrogenase-like enzyme for bacteriochlorophyll biosynthesis: reconstitution of chlorophyllide a reductase with purified X-protein (BchX) and YZ-protein (BchY-BchZ) from Rhodobacter capsulatus. J. Biol. Chem. 281 (2006) 15021-15028. [PMID: 16571720]

2. Tsukatani, Y., Yamamoto, H., Harada, J., Yoshitomi, T., Nomata, J., Kasahara, M., Mizoguchi, T., Fujita, Y. and Tamiaki, H. An unexpectedly branched biosynthetic pathway for bacteriochlorophyll b capable of absorbing near-infrared light. Sci Rep 3 (2013) 1217. [PMID: 23386973]

3. Lange, C., Kiesel, S., Peters, S., Virus, S., Scheer, H., Jahn, D. and Moser, J. Broadened substrate specificity of 3-hydroxyethyl bacteriochlorophyllide a dehydrogenase (BchC) indicates a new route for the biosynthesis of bacteriochlorophyll a. J. Biol. Chem. 290 (2015) 19697-19709. [PMID: 26088139]

4. Harada, J., Mizoguchi, T., Tsukatani, Y., Yokono, M., Tanaka, A. and Tamiaki, H. Chlorophyllide a oxidoreductase works as one of the divinyl reductases specifically involved in bacteriochlorophyll a biosynthesis. J. Biol. Chem. 289 (2014) 12716-12726. [PMID: 24637023]

[EC created 1965 as EC, modified 2012, transferred 2016 to EC]

Return to EC 1.3.7 home page
Return to EC 1.3 home page
Return to EC 1 home page
Return to Enzymes home page
Return to IUBMB Biochemical Nomenclature home page