title: In vitro activity of C-20 methyltransferase, BchU, involved in bacteriochlorophyll c biosynthetic pathway in green sulfur bacteria.
abstract: The activity of a methyltransferase, BchU, which catalyzes methylation at the C-20 position of chlorin ring in the biosynthetic pathway of bacteriochlorophyll c, was investigated in vitro. The bchU gene derived from the photosynthetic green sulfur bacterium, Chlorobium tepidum, was overexpressed in Escherichia coli as a His-tagged protein (His(6)-BchU), and the enzyme was purified. In the presence of S-adenosylmethionine, His(6)-BchU methylated zinc bacteriopheophorbide d at the C-20 position to give zinc bacteriopheophorbide c. Metal-free bacteriopheophorbide d could not be methylated by the BchU, indicating that the central metal in the chlorin should be required for the recognition by the BchU.
authors.affiliation: Department of Bioscience and Biotechnology, Faculty of Science and Engineering, Ritsumeikan University, Kusatsu, Shiga 525-8577, Japan.
authors.forename: Jiro
authors.initials: J
authors.lastname: Harada
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Saga
authors.forename: Yuki
authors.initials: Y
authors.lastname: Yaeda
authors.forename: Hirozo
authors.initials: H
authors.lastname: Oh-Oka
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Tamiaki
mesh_terms: D001426:Bacterial Proteins / Q000096:biosynthesis* / Q000737:chemistry* / Q000302:isolation & purification / Q000502:physiology; D001429:Bacteriochlorophylls / Q000096:biosynthesis*; D041883:Chlorobium / Q000201:enzymology* / Q000235:genetics; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics; D005798:Genes, Bacterial; D008780:Methyltransferases / Q000737:chemistry* / Q000302:isolation & purification / Q000502:physiology; D013379:Substrate Specificity
chemical_list: D001426:Bacterial Proteins; D001429:Bacteriochlorophylls; C002084:bacteriochlorophyll c; D008780:Methyltransferases