title: Characterization of chlorophyll a and bacteriochlorophyll a synthases by heterologous expression in Escherichia coli.
abstract: Genes coding for putative chlorophyll a synthase (chlG) from Synechocystis sp. PCC 6803 and bacteriochlorophyll a synthase (bchG) from Rhodobacter capsulatus were amplified by the polymerase chain reaction and cloned into T7 RNA polymerase-based expression plasmids. In vitro enzymatic assays indicated that heterologous expression of the chlG and bchG gene products in Escherichia coli conferred chlorophyll a and bacteriochlorophyll a synthase activity, respectively. Chlorophyll a synthase utilized chlorophyllide a, but not bacteriochlorophyllide a, as a substrate, whereas bacteriochlorophyll a synthase utilized bacteriochlorophyllide a, but not chlorophyllide a. Both enzymes were also observed to exhibit a marked preference for phytyl diphosphate over geranylgeranyl diphosphate.
authors.affiliation: Botanisches Institut der Universität München, 86038 München, Federal Republic of Germany.
authors.forename: U
authors.initials: U
authors.lastname: Oster
authors.forename: C E
authors.initials: CE
authors.lastname: Bauer
authors.forename: W
authors.initials: W
authors.lastname: Rüdiger
mesh_terms: D001429:Bacteriochlorophylls / Q000096:biosynthesis*; D019729:Carbon-Oxygen Ligases; D002734:Chlorophyll / Q000096:biosynthesis*; D000077194:Chlorophyll A; D002851:Chromatography, High Pressure Liquid; D004926:Escherichia coli; D008025:Ligases / Q000235:genetics* / Q000378:metabolism; D010860:Pigments, Biological / Q000096:biosynthesis*; D013056:Spectrophotometry, Ultraviolet
chemical_list: D001429:Bacteriochlorophylls; D010860:Pigments, Biological; D002734:Chlorophyll; D008025:Ligases; D019729:Carbon-Oxygen Ligases; C105512:bacteriochlorophyll a synthase; C026901:chlorophyll synthetase; D000077194:Chlorophyll A