Excitation migration in trimeric cyanobacterial photosystem I.
A structure-based description of excitation migration in multireaction center light harvesting systems is introduced. The description is an extension of the sojourn expansion, which decomposes excitation migration in terms of repeated detrapping and recapture events. The approach is applied to light harvesting in the trimeric form of cyanobacterial photosystem I (PSI). Excitation is found to be shared between PSI monomers and the chlorophylls providing the strongest respective links are identified. Excitation sharing is investigated by computing cross-monomer excitation trapping probabilities. It is seen that on the average there is a nearly 40% chance of excitation cross transfer and trapping, indicating efficient coupling between monomers. The robustness and optimality of the chlorophyll network of trimeric PSI is examined.
Beckman Institute, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
Melih K
MK
Sener
Sanghyun
S
Park
Deyu
D
Lu
Ana
A
Damjanovic
Thorsten
T
Ritz
Petra
P
Fromme
Klaus
K
Schulten
D002734:Chlorophyll / Q000737:chemistry* / Q000528:radiation effects; D003198:Computer Simulation; D000458:Cyanobacteria / Q000737:chemistry* / Q000528:radiation effects; D004579:Electron Transport; D008027:Light; D008954:Models, Biological; D008956:Models, Chemical; D008958:Models, Molecular; D017785:Photons; D045331:Photosystem I Protein Complex / Q000737:chemistry* / Q000528:radiation effects
D045331:Photosystem I Protein Complex; D002734:Chlorophyll