1aig
From Proteopedia
|
PHOTOSYNTHETIC REACTION CENTER FROM RHODOBACTER SPHAEROIDES IN THE D+QB-CHARGE SEPARATED STATE
Overview
High resolution x-ray diffraction data from crystals of the Rhodobacter sphaeroides photosynthetic reaction center (RC) have been collected at cryogenic temperature in the dark and under illumination, and the structures were refined at 2.2 and 2.6 angstrom resolution, respectively. In the charge-separated D+QAQB- state (where D is the primary electron donor (a bacteriochlorophyll dimer), and QA and QB are the primary and secondary quinone acceptors, respectively), QB- is located approximately 5 angstroms from the QB position in the charge-neutral (DQAQB) state, and has undergone a 180 degrees propeller twist around the isoprene chain. A model based on the difference between the two structures is proposed to explain the observed kinetics of electron transfer from QA-QB to QAQB- and the relative binding affinities of the different ubiquinone species in the QB pocket. In addition, several water channels (putative proton pathways) leading from the QB pocket to the surface of the RC were delineated, one of which leads directly to the membrane surface.
About this Structure
1AIG is a Protein complex structure of sequences from Rhodobacter sphaeroides with , , and as ligands. Full crystallographic information is available from OCA.
Reference
Light-induced structural changes in photosynthetic reaction center: implications for mechanism of electron-proton transfer., Stowell MH, McPhillips TM, Rees DC, Soltis SM, Abresch E, Feher G, Science. 1997 May 2;276(5313):812-6. PMID:9115209
Page seeded by OCA on Thu Feb 21 11:44:50 2008
