EC - Chlorophyllide a reductase

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IntEnz Enzyme Nomenclature


Accepted name:
chlorophyllide a reductase
Other names:
bchX (gene name)
bchY (gene name)
bchZ (gene name)
Systematic name:
bacteriochlorophyllide-a:ferredoxin 7,8-oxidoreductase




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

Enzymes and pathways: NC-IUBMB , BRENDA , DIAGRAM , ExplorEnz , ENZYME@ExPASy , KEGG , MetaCyc , UniPathway
Structural data: CSA , EC2PDB
UniProtKB/Swiss-Prot: (10) [show] [UniProt]


  1. Nomata, J., Mizoguchi, T., Tamiaki, H., 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 : 15021-15028 (2006). [PMID: 16571720]
  2. Tsukatani, Y., Yamamoto, H., Harada, J., Yoshitomi, T., Nomata, J., Kasahara, M., Mizoguchi, T., Fujita, Y., Tamiaki, H.
    An unexpectedly branched biosynthetic pathway for bacteriochlorophyll b capable of absorbing near-infrared light.
    Sci Rep 3 : 1217 (2013). [PMID: 23386973]
  3. Lange, C., Kiesel, S., Peters, S., Virus, S., Scheer, H., Jahn, D., 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 : 19697-19709 (2015). [PMID: 26088139]
  4. Harada, J., Mizoguchi, T., Tsukatani, Y., Yokono, M., Tanaka, A., Tamiaki, H.
    Chlorophyllide a oxidoreductase works as one of the divinyl reductases specifically involved in bacteriochlorophyll a biosynthesis.
    J. Biol. Chem. 289 : 12716-12726 (2014). [PMID: 24637023]

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