Structural adaptations of photosynthetic complex I enable ferredoxin-dependent electron transfer

Jan M. Schuller; James A. Birrell; Hideaki Tanaka; Tsuyoshi Konuma; Hannes Wulfhorst; Nicholas Cox; Sandra K. Schuller; Jacqueline Thiemann; Wolfgang Lubitz; Pierre Sétif; Takahisa Ikegami; Benjamin D. Engel; Genji Kurisu; Marc M. Nowaczyk

Structural adaptations of photosynthetic complex I enable ferredoxin-dependent electron transfer

Jan M. Schuller ¹ James A. Birrell ² Hideaki Tanaka ³ Tsuyoshi Konuma ⁴ Hannes Wulfhorst ⁵ Nicholas Cox ² Sandra K. Schuller ⁶ Jacqueline Thiemann ⁵ Wolfgang Lubitz ² Pierre Sétif ⁷ Takahisa Ikegami ⁸ Benjamin D. Engel ¹ Genji Kurisu ³ Marc M. Nowaczyk

1 MPIB - Max Planck Institute of Biochemistry

2 Max Planck Institute for Chemical Energy Conversion

3 Institute for Protein Research [Osaka]

4 YCUSM - Yokohama City University School of Medecine

5 RUB - Ruhr University Bochum

6 LMU - Ludwig-Maximilians-Universität München

7 I2BC - Institut de Biologie Intégrative de la Cellule

8 Yokohama City University

Abstract : Photosynthetic complex I enables cyclic electron flow around photosystem I, a regulatory mechanism for photosynthetic energy conversion. We report a 3.3-angstrom-resolution cryo–electron microscopy structure of photosynthetic complex I from the cyanobacterium Thermosynechococcus elongatus. The model reveals structural adaptations that facilitate binding and electron transfer from the photosynthetic electron carrier ferredoxin. By mimicking cyclic electron flow with isolated components in vitro, we demonstrate that ferredoxin directly mediates electron transfer between photosystem I and complex I, instead of using intermediates such as NADPH (the reduced form of nicotinamide adenine dinucleotide phosphate). A large rate constant for association of ferredoxin to complex I indicates efficient recognition, with the protein subunit NdhS being the key component in this process.

Document type :

Journal articles

Domain :

Life Sciences [q-bio] / Cellular Biology

Complete list of metadatas

https://hal-cea.archives-ouvertes.fr/cea-02065421
Contributor : Bruno Savelli <>
Submitted on : Tuesday, March 12, 2019 - 4:31:40 PM
Last modification on : Thursday, July 18, 2019 - 2:54:10 PM

Structural adaptations of photosynthetic complex I enable ferredoxin-dependent electron transfer

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Structural adaptations of photosynthetic complex I enable ferredoxin-dependent electron transfer

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