Atomically defined mechanism for proton transfer to a buried redox centre in a protein

Kaisheng Chen, Judy Hirst, Raul Camba, Christopher A. Bonagura, C. David Stout, Barbara. K. Burgess and Fraser A. Armstrong ()
Additional contact information
Kaisheng Chen: University of California
Judy Hirst: Oxford University
Raul Camba: Oxford University
Christopher A. Bonagura: University of California
C. David Stout: Department of Molecular Biology The Scripps Research Institute
Barbara. K. Burgess: University of California
Fraser A. Armstrong: Oxford University

Nature, 2000, vol. 405, issue 6788, 814-817

Abstract: Abstract The basis of the chemiosmotic theory is that energy from light or respiration is used to generate a trans-membrane proton gradient1. This is largely achieved by membrane-spanning enzymes known as ‘proton pumps’2,3,4,5. There is intense interest in experiments which reveal, at the molecular level, how protons are drawn through proteins6,7,8,9,10,11,12,13.Here we report the mechanism, at atomic resolution, for a single long-range electron-coupled proton transfer. In Azotobacter vinelandii ferredoxin I, reduction of a buried iron–sulphur cluster draws in a solvent proton, whereas re-oxidation is ‘gated’ by proton release to the solvent. Studies of this ‘proton-transferring module’ by fast-scan protein film voltammetry, high-resolution crystallography, site-directed mutagenesis and molecular dynamics, reveal that proton transfer is exquisitely sensitive to the position and pK of a single amino acid. The proton is delivered through the protein matrix by rapid penetrative excursions of the side-chain carboxylate of a surface residue (Asp 15), whose pK shifts in response to the electrostatic charge on the iron–sulphur cluster. Our analysis defines the structural, dynamic and energetic requirements for proton courier groups in redox-driven proton-pumping enzymes.

Date: 2000
References: Add references at CitEc
Citations:

Downloads: (external link)
https://www.nature.com/articles/35015610 Abstract (text/html)
Access to the full text of the articles in this series is restricted.

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:nat:nature:v:405:y:2000:i:6788:d:10.1038_35015610

Ordering information: This journal article can be ordered from
https://www.nature.com/

DOI: 10.1038/35015610

Access Statistics for this article

Nature is currently edited by Magdalena Skipper

More articles in Nature from Nature
Bibliographic data for series maintained by Sonal Shukla () and Springer Nature Abstracting and Indexing ().