| | Tuning electron transfer by ester-group of chlorophylls in bacterial photosynthetic reaction center☆Edited by Peter Brzezinski Received 7 December 2004; received in revised form 20 December 2004; accepted 20 December 2004. published online 04 January 2005. Abstract Accessory chlorophylls (BA/B) in bacterial photosynthetic reaction center play a key role in charge-separation. Although light-exposed and dark-adapted bRC crystal structures are virtually identical, the calculated BA redox potentials for one-electron reduction differ. This can be traced back to different orientations of the BA ester-group. This tuning ability of chlorophyll redox potentials modulates the electron transfer from SP* to BA. Abbreviations: BA/B, accessory bacteriochlorophyll in A/B-branch of bRC, BChla, bacteriochlorophylla, Bpheoa, bacteriopheophytina, bRC, reaction centers from purple bacteria, Chla, chlorophylla, ChlD1/D2, accessory chlorophyll in D1/D2-branch of PSII, Em, (midpoint) redox potential, ET, electron transfer, HA, bacteriopheophytina of the A-branch, PSII, photosystem II, R. sphaeroides, Rhodobacter sphaeroides, SP, special pair BChla, SP*, special pair in the electronic excited state Institute of Chemistry, Crystallography, Department of Biology, Chemistry, and Pharmacy, Free University of Berlin, Takustrasse 6, D-14195 Berlin, Germany  Corresponding author. Fax: +49 30 83856921
☆ We thank the Deutsche Forschungsgemeinschaft Sfb498, GRK80/2, GRK268, GRK788/1 and the Fond der Chemischen Industrie with the BMFT. H.I. was supported by the DAAD. PII: S0014-5793(04)01605-9 doi:10.1016/j.febslet.2004.12.049 © 2005 Federation of European Biochemical Societies | |
|
|
ABSTRACT
