The enzyme, together with EC 1.1.1.396, bacteriochlorophyllide-a dehydrogenase, and EC 4.2.1.165, 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 1.3.7.13, 3,8-divinyl protochlorophyllide a 8-vinyl-reductase (ferredoxin) . The enzyme contains a [4Fe-4S] cluster, and structurally resembles the Fe protein/MoFe protein complex of nitrogenase (EC 1.18.6.1), which catalyses an ATP-driven reduction.
The enzyme, together with EC 1.1.1.396, bacteriochlorophyllide-a dehydrogenase, and EC 4.2.1.165, 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 1.3.7.13, 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 1.18.6.1), which catalyses an ATP-driven reduction.
holoenzyme is composed of subunits BchX, BchY, and BchZ, and reduces ring B of chlorophyllide a using NADH under anaerobic conditions. It generates superoxide at low O2 concentrations. Superoxide is generated not from FMN of reductase subunit BchX but from heme of subunit BchZ
holoenzyme is composed of subunits BchX, BchY, and BchZ, and reduces ring B of chlorophyllide a using NADH under anaerobic conditions. It generates superoxide at low O2 concentrations. Superoxide is generated not from FMN of reductase subunit BchX but from heme of subunit BchZ
heterologous expression of subunits bchXYZ in Synechocystis sp. PCC6803 results in decrease in photosynthetic growth. An increase in cytosolic superoxide dismutase level in the recombinant Synechocystis sp. PCC6803 completely reversed the growth cessation, demonstraing that chlorophyllide a reductase generates superoxide in Synechocystis sp. PCC6803
the bchA locus contains three genes bchX, Y and Z, which are essential for the reduction of 2-devinyl-2-hydroxyethyl chlorophyllide a. BchX may supply electrons for reduction of 2-devinyl-2-hydroxyethyl chlorophyllide a
heterologous expression of subunits bchXYZ in Synechocystis sp. PCC6803 results in decrease in photosynthetic growth. An increase in cytosolic superoxide dismutase level in the recombinant Synechocystis sp. PCC6803 completely reversed the growth cessation, demonstraing that chlorophyllide a reductase generates superoxide in Synechocystis sp. PCC6803
the bchA locus contains three genes bchX, Y and Z, which are essential for the reduction of 2-devinyl-2-hydroxyethyl chlorophyllide a. BchX may supply electrons for reduction of 2-devinyl-2-hydroxyethyl chlorophyllide a
reconstitution of chlorophyllide a reductase with purified proteins. Two Rhodobacter capsulatus strains that overexpress Strep-tagged BchX and BchY are isolated. Strep-tagged BchX is purified as a single polypeptide, and BchZ is co-purified with Strep-tagged BchY. When BchX and BchY-BchZ components are incubated with chlorophyllide a, ATP, and dithionite under anaerobic conditions, chlorophyllide a is converted to a new pigment
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
Evidence for the presence of key chlorophyll-biosynthesis-related proteins in the genus Rubrobacter (Phylum Actinobacteria) and its implications for the evolution and origin of photosynthesis
Photosynth. Res.
127
201-218
2016
no activity in Rubrobacter xylanophilus, no activity in Rubrobacter radiotolerans
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1.3.7.15 chlorophyllide a reductase
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