Cryo-EM structure of a photosystem I variant containing an unusual plastoquinone derivative in its electron transfer chain

Christopher J Gisriel; Vasily Kurashov; David F Iwig; Brandon P Russell; David J Vinyard; Gary W Brudvig; John H Golbeck; K V Lakshmi

doi:10.1126/sciadv.adp4937

Cryo-EM structure of a photosystem I variant containing an unusual plastoquinone derivative in its electron transfer chain

Sci Adv. 2024 Nov 29;10(48):eadp4937. doi: 10.1126/sciadv.adp4937. Epub 2024 Nov 29.

Authors

Christopher J Gisriel^{1

2}, Vasily Kurashov³, David F Iwig^{4

5}, Brandon P Russell⁶, David J Vinyard⁶, Gary W Brudvig^{1

7}, John H Golbeck³, K V Lakshmi⁸

Affiliations

¹ Department of Chemistry, Yale University, New Haven, CT 06520-8107, USA.
² Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA.
³ Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA.
⁴ Department of Chemistry and Howard Hughes Medical Institute, The Pennsylvania State University, University Park, PA 16802, USA.
⁵ Howard Hughes Medical Institute, 4000 Jones Bridge Rd, Chevy Chase, MD 20815, USA.
⁶ Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, USA.
⁷ Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520-8114, USA.
⁸ Department of Chemistry and Chemical Biology and The Baruch '60 Center for Biochemical Solar Energy Research, Rensselaer Polytechnic Institute, Troy, NY 12180, USA.

Abstract

Photosystem I (PS I) is a light-driven oxidoreductase responsible for converting photons into chemical bond energy. Its application for renewable energy was revolutionized by the creation of the MenB deletion (ΔmenB) variant in the cyanobacterium Synechocystis sp. PCC 6803, in which phylloquinone is replaced by plastoquinone-9 with a low binding affinity. This permits its exchange with exogenous quinones covalently coupled to dihydrogen catalysts that bind with high affinity, thereby converting PS I into a stable solar fuel catalyst. Here, we reveal the 2.03-Å-resolution cryo-EM structure of a recent MenB variant of PS I. The quinones and their binding environment are analyzed in the context of previous biophysical data, thereby enabling a protocol to solve future PS I hybrids and constructs from this genetically tractable cyanobacterium.

MeSH terms

Cryoelectron Microscopy* / methods
Electron Transport
Models, Molecular
Photosystem I Protein Complex* / chemistry
Photosystem I Protein Complex* / genetics
Photosystem I Protein Complex* / metabolism
Plastoquinone* / chemistry
Plastoquinone* / metabolism
Synechocystis* / chemistry
Synechocystis* / genetics
Synechocystis* / metabolism

Substances

Photosystem I Protein Complex
Plastoquinone