Light-induced structural changes in a photosynthetic reaction center caught by Laue diffraction.
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.
Wöhri
Annemarie B
AB
Department of Chemical and Biological Engineering, Chalmers University of Technology, Box 462, SE-40530 Göteborg, Sweden.
Katona
Gergely
G
Johansson
Linda C
LC
Fritz
Emelie
E
Malmerberg
Erik
E
Andersson
Magnus
M
Vincent
Jonathan
J
Eklund
Mattias
M
Cammarata
Marco
M
Wulff
Michael
M
Davidsson
Jan
J
Groenhof
Gerrit
G
Neutze
Richard
R
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
D001426:Bacterial Proteins; D001429:Bacteriochlorophylls; D045322:Photosynthetic Reaction Center Complex Proteins; D011522:Protons; D011809:Quinones; D045304:Cytochromes c