title: N-terminal methylation of the core light-harvesting complex in purple photosynthetic bacteria.
abstract: Several core light-harvesting complexes from both sulfur and non-sulfur purple photosynthetic bacteria have been identified to be methylated at the N-terminal alpha-amino group of beta-polypeptides by using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and nuclear magnetic resonance. Monomethylation has been confirmed for the N-terminal alanine residues of the beta-polypeptides from Rhodospirillum rubrum, Thermochromatium tepidum and Chromatium vinosum, but not for the beta-polypeptide from Rhodobacter sphaeroides. The modification appears to be related with the amino acid sequence and charge distribution in the N-terminal end. Some common features and possible functions are discussed.
authors.affiliation: Department of Biomolecular Engineering, Faculty of Engineering, Center for Interdisciplinary Research, Tohoku University, Sendai, Japan. wang@biophys.che.tohoku.ac.jp
authors.forename: Zheng Yu
authors.initials: ZY
authors.lastname: Wang
authors.forename: Masahiro
authors.initials: M
authors.lastname: Shimonaga
authors.forename: Masayuki
authors.initials: M
authors.lastname: Kobayashi
authors.forename: Tsunenori
authors.initials: T
authors.lastname: Nozawa
mesh_terms: D002844:Chromatium / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D009682:Magnetic Resonance Spectroscopy; D008745:Methylation; D008970:Molecular Weight; D010446:Peptide Fragments / Q000737:chemistry; D045322:Photosynthetic Reaction Center Complex Proteins / Q000737:chemistry*; D012242:Rhodobacter sphaeroides / Q000737:chemistry*; D012247:Rhodospirillum rubrum / Q000737:chemistry*; D020539:Sequence Analysis, Protein; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D010446:Peptide Fragments; D045322:Photosynthetic Reaction Center Complex Proteins