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

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
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 : Tuesday, November 26, 2019 - 2:50:28 PM

Identifiers

Citation

Jan M. Schuller, James A. Birrell, Hideaki Tanaka, Tsuyoshi Konuma, Hannes Wulfhorst, et al.. Structural adaptations of photosynthetic complex I enable ferredoxin-dependent electron transfer. Science, American Association for the Advancement of Science, 2019, 363 (6424), pp.257-260. ⟨10.1126/science.aau3613 ⟩. ⟨cea-02065421⟩

Share

Metrics

Record views

52