4.2.1.165: chlorophyllide a 31-hydratase

Q53222

deletion of gene bchF in a bacteriochlorophyll (BChl) b-producing strain of Rhodobacter sphaeroides leads to the production of an analogue of bacteriochlorophyllide g, BChl gP, where P is phytyl, rather than the native BChl aP. In the bchF-deletion mutant, hydration of the C3-vinyl group in 3-vinyl bacteriochlorophyllide a is blocked, but this precursor can be esterified with phytol. Enzyme BchF deletion- in the DELTAbciA/bchXYZBv background results in formation of BChl g esterified with phytol (BChl gP). Pigment analysis in several bch mutants, overview

747177

further methylation at the 82- and 20-positions suppresses the in vitro hydration of the 3-vinyl group by the BchF/V hydratases. In vivo experiments with bchF-deleted mutants show considerably lower levels of bacteriochlorophyll a than the wild-type strain

pigment analyses of the bchF-inactivated mutant, which still has BchV as a sole hydratase, show higher ratios of S-epimeric bacteriochlorophyll c than the wild-type strain, while the bchV-mutant possessing only BchF showed a significant decrease of the S-epimers and accumulations of C3-vinyl BChl c species. In BChl a biosynthesis, the C3-vinyl group of a precursor of BChl a is hydrated by BchF, and the C3-1-hydroxyethyl group is then oxidized to the acetyl moiety by BchC

748684

Chlorobaculum tepidum ATCC 49652 / DSM 12025 / NBRC 103806 / TLS

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pigment analyses of the bchF-inactivated mutant, which still has BchV as a sole hydratase, show higher ratios of S-epimeric bacteriochlorophyll c than the wild-type strain, while the bchV-mutant possessing only BchF showed a significant decrease of the S-epimers and accumulations of C3-vinyl BChl c species. In BChl a biosynthesis, the C3-vinyl group of a precursor of BChl a is hydrated by BchF, and the C3-1-hydroxyethyl group is then oxidized to the acetyl moiety by BchC

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further methylation at the 82- and 20-positions suppresses the in vitro hydration of the 3-vinyl group by the BchF/V hydratases. In vivo experiments with bchF-deleted mutants show considerably lower levels of bacteriochlorophyll a than the wild-type strain

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metabolism

H2VFK0

BchF may specifically be required for bacteriochlorophyll a biosynthesis

741110

enzyme involvement in the biosynthetic pathways of BChl c homologues and epimers, overview

748858

proposed biosynthetic pathways of bacteriochlorophyllides a and c focused on Chlorobaculum tepidum BchF- and BchV-catalyzed reactions, overview

748684

Chlorobaculum tepidum DSM 12025

Q53222

the enzyme is involved in the biosynthetic pathways of different baceriochlorophyllides, e.g. a and g, overview

747177

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BchF may specifically be required for bacteriochlorophyll a biosynthesis

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Chlorobaculum tepidum ATCC 49652 / DSM 12025 / NBRC 103806 / TLS

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proposed biosynthetic pathways of bacteriochlorophyllides a and c focused on Chlorobaculum tepidum BchF- and BchV-catalyzed reactions, overview

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physiological function

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a bacteriochlorophyll-less mutant of Rhodopseudomonas sphaeroides excretes tetrapyrrole-protein complex into the incubation medium. The major pigment of the complex is 2-desacetyl-2-vinylbacteriopheophorbide, indicating the existence of an alternate pathway of bacteriochlorophyll synthesis. This implies that reduction from the chlorin to the tetrahydroporphyrin stage can occur either before or after hydration of the 2-vinyl substituent of chlorophyllide a to an a-hydroxyethyl group. The mutant is presumably deficient in the enzyme responsible for hydration of the 2-vinyl to the 2-alpha-hydroxyethyl group

737663

Rhodobacter capsulatus

P26165

bchF encodes a bacteriochlorophyll a-specific enzyme that adds water across the 2-vinyl group in bacteriochlorophyll synthesis

712268

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deficiency in BchF impairs the production of both bacteriochlorophyllide a and bacteriochlorophyllide c.Pigment analyses of the BchF inactivated mutant, which still has BchV as a sole hydratase, shows higher ratios of S-epimeric bacteriochlorophyll c than the wild-type strain. The heightened prevalence of S-stereoisomers in the mutant is more remarkable at lower light intensities and causes a red shift of the chlorosomal Qy absorption band leading to advantages for light-energy transfer

739109

H2VFK0

in the bacteriochlorophyll a biosynthetic pathway, hydration of the C-3 vinyl group is catalyzed by BchF. Chlorobium tepidum gene bchF complements Rhodobacter capsulatus strains defective in specific steps of bacteriochlorophyll a biosynthesis

741110

Chloroflexus aurantiacus

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a chlorosome is a large and efficient light-harvesting antenna system found in some photosynthetic bacteria. This system comprises self-aggregates of bacteriochlorophyll (BChl) c, d, or e possessing a chiral 1-hydroxyethyl group at the 3-position, which plays a key role in the formation of the supramolecule. Biosynthesis of chlorosomal pigments involves stereoselective conversion of 3-vinyl group to 3-(1-hydroxyethyl) group facilitated by a 3-vinyl hydratase. This 3-vinyl hydration also occurs in BChl a biosynthesis, followed by oxidation that introduces an acetyl group at the 3-position catalyzed by 3-vinyl hydratases. Analysis of the biosynthetic pathway of bacteriochlorophyll a and other chlorosomal pigments considering the substrate specificity and stereoselectivity, and comparisons of by 3-vinyl hydratases derived from green sulfur bacteria, overview. Chloroflexus aurantiacus possesses a 2:1 mixture of R/S[E,M]BChls c

Chloracidobacterium thermophilum

G2LJR9

a chlorosome is a large and efficient light-harvesting antenna system found in some photosynthetic bacteria. This system comprises self-aggregates of bacteriochlorophyll (BChl) c, d, or e possessing a chiral 1-hydroxyethyl group at the 3-position, which plays a key role in the formation of the supramolecule. Biosynthesis of chlorosomal pigments involves stereoselective conversion of 3-vinyl group to 3-(1-hydroxyethyl) group facilitated by a 3-vinyl hydratase. This 3-vinyl hydration also occurs in BChl a biosynthesis, followed by oxidation that introduces an acetyl group at the 3-position catalyzed by 3-vinyl hydratases. Analysis of the biosynthetic pathway of BChl a and other chlorosomal pigments considering the substrate specificity and stereoselectivity, and comparisons of by 3-vinyl hydratases derived from green sulfur bacteria, overview

Chlorobaculum limnaeum

A0A1D8D5T2

a chlorosome is a large and efficient light-harvesting antenna system found in some photosynthetic bacteria. This system comprises self-aggregates of bacteriochlorophyll (BChl) c, d, or e possessing a chiral 1-hydroxyethyl group at the 3-position, which plays a key role in the formation of the supramolecule. Biosynthesis of chlorosomal pigments involves stereoselective conversion of 3-vinyl group to 3-(1-hydroxyethyl) group facilitated by a 3-vinyl hydratase. This 3-vinyl hydration also occurs in BChl a biosynthesis, followed by oxidation that introduces an acetyl group at the 3-position catalyzed by 3-vinyl hydratases. Analysis of the biosynthetic pathway of BChl a and other chlorosomal pigments considering the substrate specificity and stereoselectivity, and comparisons of by 3-vinyl hydratases derived from green sulfur bacteria, overview

a chlorosome is a large and efficient light-harvesting antenna system found in some photosynthetic bacteria. This system comprises self-aggregates of bacteriochlorophyll (BChl) c, d, or e possessing a chiral 1-hydroxyethyl group at the 3-position, which plays a key role in the formation of the supramolecule. Biosynthesis of chlorosomal pigments involves stereoselective conversion of 3-vinyl group to 3-(1-hydroxyethyl) group facilitated by a 3-vinyl hydratase. This 3-vinyl hydration also occurs in BChl a biosynthesis, followed by oxidation that introduces an acetyl group at the 3-position catalyzed by 3-vinyl hydratases. Analysis of the biosynthetic pathway of BChl a and other chlorosomal pigments considering the substrate specificity and stereoselectivity, and comparisons of by 3-vinyl hydratases derived from green sulfur bacteria, overview. The green sulfur bacterium Chlorobaculum tepidum synthesizes three types of chlorophyllous pigments: Chl aPD (Chl a esterified with DELTA2,6-phytadienol), BChl a, and BChl c. The core part of chlorosomes in Chlorobaculum tepidum consists of self-aggregates of BChl c molecules, which are a mixture of 31R/S-epimers as well as a mixture of 82-and 121-methylated homologues. In the cells, the chiral 31-carbon of BChl c species possessing the 8-ethyl group, 8-ethyl-12-methyl-([E,M]), and 8,12-diethyl-([E,E])BChls c, exclusively shows R-stereochemistry. The single 82-methylated species, 8-propyl-12-ethyl-([P,E])bacteriochlorophyll c, is a 9:1 mixture of 31R- and 31S-epimers, and bacteriochlorophyll c species with one more 82-methylation, 8-isobutyl-12-ethyl-([I,E])bacteriochlorophyll c, predominantly produces a 31S-epimer. Both BchF and BchV can hydrate the 3-vinyl group of chlorophyllide a as a substrate of the hydratases in the bacteriochlorophyll a biosynthetic pathway. Both BchF and BchV play a role in bacteriochlorophyll a biosynthesis, but BchF has a lower substrate specificity to the precursors of bacteriochlorophyll a than BchV

bacteriochlorophyll a requires formation of a 3-hydroxyethyl group on pyrrole ring A that is subsequently converted into a 3-acetyl group by 3-vinyl bacteriochlorophyllide a hydratase (BchF) followed by 3-hydroxyethyl bacteriochlorophyllide a dehydrogenase (BchC)

748192

Q53222

gene bchF encodes an enzyme responsible for the hydration of the C3-vinyl group of a precursor of bacteriochlorophylls

747177

photosynthetic green sulfur bacteria inhabit anaerobic environments with very low-light conditions. Stereochemical conversion of C3-vinyl group to 1-hydroxyethyl group in bacteriochlorophyll c by the hydratases BchF and BchV (EC 4.2.1.169) for adaptation of green sulfur bacteria to limited-light environments. The pigment possess a hydroxy group at the C31 position that produces a chiral center with R- or S-stereochemistry and the C31-hydroxy group serves as a connecting moiety for the self-aggregation

748684