title: Light-induced structural changes in a photosynthetic reaction center caught by Laue diffraction.
abstract: Photosynthetic reaction centers convert the energy content of light into a transmembrane potential difference and so provide the major pathway for energy input into the biosphere. We applied time-resolved Laue diffraction to study light-induced conformational changes in the photosynthetic reaction center complex of Blastochloris viridis. The side chain of TyrL162, which lies adjacent to the special pair of bacteriochlorophyll molecules that are photooxidized in the primary light conversion event of photosynthesis, was observed to move 1.3 angstroms closer to the special pair after photoactivation. Free energy calculations suggest that this movement results from the deprotonation of this conserved tyrosine residue and provides a mechanism for stabilizing the primary charge separation reactions of photosynthesis.
authors.affiliation: Department of Chemical and Biological Engineering, Chalmers University of Technology, Box 462, SE-40530 Göteborg, Sweden.
authors.forename: Annemarie B
authors.initials: AB
authors.lastname: Wöhri
authors.forename: Gergely
authors.initials: G
authors.lastname: Katona
authors.forename: Linda C
authors.initials: LC
authors.lastname: Johansson
authors.forename: Emelie
authors.initials: E
authors.lastname: Fritz
authors.forename: Erik
authors.initials: E
authors.lastname: Malmerberg
authors.forename: Magnus
authors.initials: M
authors.lastname: Andersson
authors.forename: Jonathan
authors.initials: J
authors.lastname: Vincent
authors.forename: Mattias
authors.initials: M
authors.lastname: Eklund
authors.forename: Marco
authors.initials: M
authors.lastname: Cammarata
authors.forename: Michael
authors.initials: M
authors.lastname: Wulff
authors.forename: Jan
authors.initials: J
authors.lastname: Davidsson
authors.forename: Gerrit
authors.initials: G
authors.lastname: Groenhof
authors.forename: Richard
authors.initials: R
authors.lastname: Neutze
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism; D001429:Bacteriochlorophylls / Q000737:chemistry / Q000378:metabolism; D018360:Crystallography, X-Ray; D045304:Cytochromes c / Q000737:chemistry / Q000378:metabolism; D004579:Electron Transport; D006860:Hydrogen Bonding; D006863:Hydrogen-Ion Concentration; D041921:Hyphomicrobiaceae / Q000737:chemistry* / Q000378:metabolism; D008027:Light; D008958:Models, Molecular; D056004:Molecular Dynamics Simulation; D010084:Oxidation-Reduction; D045322:Photosynthetic Reaction Center Complex Proteins / Q000737:chemistry* / Q000378:metabolism; D011487:Protein Conformation; D011522:Protons; D011809:Quinones / Q000737:chemistry / Q000378:metabolism; D013816:Thermodynamics
chemical_list: D001426:Bacterial Proteins; D001429:Bacteriochlorophylls; D045322:Photosynthetic Reaction Center Complex Proteins; D011522:Protons; D011809:Quinones; D045304:Cytochromes c