7M78

Room Temperature XFEL Crystallography reveals asymmetry in the vicinity of the two phylloquinones in Photosystem I

Summary for 7M78

• Entry DOI: 10.2210/pdb7m78/pdb
• Descriptor: Photosystem I P700 chlorophyll a apoprotein A1, Photosystem I reaction center subunit XI, Photosystem I reaction center subunit XII, ... (23 entities in total)
• Functional Keywords: membrane complex, electron transport, photosynthesis
• Biological source: Thermosynechococcus elongatus (strain BP-1); More
• Total number of polymer chains: 12
• Total formula weight: 364412.80

Authors

Keable, S.M.,Simon, P.S.,Kolsch, A.,Kern, J.,Yachandra, V.K.,Zouni, A.,Yano, J. (deposition date: 2021-03-26, release date: 2021-11-24, Last modification date: 2024-12-25)

Primary citation

Keable, S.M.,Kolsch, A.,Simon, P.S.,Dasgupta, M.,Chatterjee, R.,Subramanian, S.K.,Hussein, R.,Ibrahim, M.,Kim, I.S.,Bogacz, I.,Makita, H.,Pham, C.C.,Fuller, F.D.,Gul, S.,Paley, D.,Lassalle, L.,Sutherlin, K.D.,Bhowmick, A.,Moriarty, N.W.,Young, I.D.,Blaschke, J.P.,de Lichtenberg, C.,Chernev, P.,Cheah, M.H.,Park, S.,Park, G.,Kim, J.,Lee, S.J.,Park, J.,Tono, K.,Owada, S.,Hunter, M.S.,Batyuk, A.,Oggenfuss, R.,Sander, M.,Zerdane, S.,Ozerov, D.,Nass, K.,Lemke, H.,Mankowsky, R.,Brewster, A.S.,Messinger, J.,Sauter, N.K.,Yachandra, V.K.,Yano, J.,Zouni, A.,Kern, J.
Room temperature XFEL crystallography reveals asymmetry in the vicinity of the two phylloquinones in photosystem I.
Sci Rep, 11:21787-21787, 2021

PubMed Abstract: Photosystem I (PS I) has a symmetric structure with two highly similar branches of pigments at the center that are involved in electron transfer, but shows very different efficiency along the two branches. We have determined the structure of cyanobacterial PS I at room temperature (RT) using femtosecond X-ray pulses from an X-ray free electron laser (XFEL) that shows a clear expansion of the entire protein complex in the direction of the membrane plane, when compared to previous cryogenic structures. This trend was observed by complementary datasets taken at multiple XFEL beamlines. In the RT structure of PS I, we also observe conformational differences between the two branches in the reaction center around the secondary electron acceptors A and A. The π-stacked Phe residues are rotated with a more parallel orientation in the A-branch and an almost perpendicular confirmation in the B-branch, and the symmetry breaking PsaB-Trp673 is tilted and further away from A. These changes increase the asymmetry between the branches and may provide insights into the preferential directionality of electron transfer.

PubMed: 34750381
DOI: 10.1038/s41598-021-00236-3

Experimental method

X-RAY DIFFRACTION (3 Å)