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 A1A and A1B. 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 A1A. These changes increase the asymmetry between the branches and may provide insights into the preferential directionality of electron transfer.

Details

Title
Room temperature XFEL crystallography reveals asymmetry in the vicinity of the two phylloquinones in photosystem I
Author
Keable Stephen M 1 ; Kölsch, Adrian 2 ; Simon, Philipp S 1 ; Dasgupta Medhanjali 1 ; Chatterjee Ruchira 1 ; Subramanian, Senthil Kumar 2 ; Rana, Hussein 2 ; Ibrahim, Mohamed 2 ; Kim, In-Sik 1 ; Bogacz Isabel 1 ; Makita Hiroki 1 ; Pham, Cindy C 1 ; Fuller, Franklin D 3 ; Gul Sheraz 1 ; Paley, Daniel 1 ; Lassalle, Louise 1 ; Sutherlin, Kyle D 1 ; Bhowmick Asmit 1 ; Moriarty, Nigel W 1 ; Young, Iris D 4 ; Blaschke, Johannes P 5 ; de Lichtenberg Casper 6 ; Chernev Petko 7 ; Cheah, Mun Hon 7 ; Park Sehan 8 ; Park Gisu 8 ; Kim Jangwoo 8 ; Lee, Sang Jae 8 ; Park, Jaehyun 8 ; Tono Kensuke 9 ; Owada Shigeki 9 ; Hunter, Mark S 3 ; Batyuk Alexander 3 ; Oggenfuss Roland 10 ; Sander, Mathias 10 ; Serhane, Zerdane 10 ; Ozerov Dmitry 10 ; Nass Karol 10 ; Lemke Henrik 10 ; Mankowsky Roman 10 ; Brewster, Aaron S 1 ; Messinger, Johannes 7 ; Sauter, Nicholas K 1 ; Yachandra, Vittal K 1 ; Yano Junko 1 ; Zouni Athina 2 ; Kern, Jan 1 

 Lawrence Berkeley National Laboratory, Molecular Biophysics and Integrated Bioimaging Division, Berkeley, USA (GRID:grid.184769.5) (ISNI:0000 0001 2231 4551) 
 Humboldt-Universität Zu Berlin, Institut für Biologie, Berlin, Germany (GRID:grid.7468.d) (ISNI:0000 0001 2248 7639) 
 SLAC National Accelerator Laboratory, LCLS, Menlo Park, USA (GRID:grid.445003.6) (ISNI:0000 0001 0725 7771) 
 Lawrence Berkeley National Laboratory, Molecular Biophysics and Integrated Bioimaging Division, Berkeley, USA (GRID:grid.184769.5) (ISNI:0000 0001 2231 4551); University of California, Department of Bioengineering and Therapeutic Sciences, San Francisco, USA (GRID:grid.266102.1) (ISNI:0000 0001 2297 6811) 
 Lawrence Berkeley National Laboratory, National Energy Research Scientific Computing Center, Berkeley, USA (GRID:grid.184769.5) (ISNI:0000 0001 2231 4551) 
 Uppsala University, Department of Chemistry - Ångström, Molecular Biomimetics, Uppsala, Sweden (GRID:grid.8993.b) (ISNI:0000 0004 1936 9457); Umeå University, Department of Chemistry, Umeå, Sweden (GRID:grid.12650.30) (ISNI:0000 0001 1034 3451) 
 Uppsala University, Department of Chemistry - Ångström, Molecular Biomimetics, Uppsala, Sweden (GRID:grid.8993.b) (ISNI:0000 0004 1936 9457) 
 POSTECH, Pohang Accelerator Laboratory, Pohang, Korea (GRID:grid.49100.3c) (ISNI:0000 0001 0742 4007) 
 Japan Synchrotron Radiation Research Institute, Hyogo, Japan (GRID:grid.410592.b) (ISNI:0000 0001 2170 091X); RIKEN SPring-8 Center, Hyogo, Japan (GRID:grid.472717.0) 
10  Paul Scherrer Institut, Villigen, Switzerland (GRID:grid.5991.4) (ISNI:0000 0001 1090 7501) 
Publication year
2021
Publication date
2021
Publisher
Nature Publishing Group
e-ISSN
20452322
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
2594889396
Copyright
© The Author(s) 2021. This work is published under http://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.