Mechanical Control of ATP Synthase Function: Activation Energy Difference between Tight and Loose Binding Sites

Type
Article

Authors
Beke-Somfai, Tamás
Lincoln, Per
Nordén, Bengt

KAUST Grant Number
KUK-11008-23

Date
2010-01-26

Abstract
Despite exhaustive chemical and crystal structure studies, the mechanistic details of how FoF1-ATP synthase can convert mechanical energy to chemical, producing ATP, are still not fully understood. On the basis of quantum mechanical calculations using a recent highresolution X-ray structure, we conclude that formation of the P-O bond may be achieved through a transition state (TS) with a planar PO3 - ion. Surprisingly, there is a more than 40 kJ/mol difference between barrier heights of the loose and tight binding sites of the enzyme. This indicates that even a relatively small change in active site conformation, induced by the γ-subunit rotation, may effectively block the back reaction in βTP and, thus, promote ATP. © 2009 American Chemical Society.

Citation
Beke-Somfai T, Lincoln P, Nordén B (2010) Mechanical Control of ATP Synthase Function: Activation Energy Difference between Tight and Loose Binding Sites. Biochemistry 49: 401–403. Available: http://dx.doi.org/10.1021/bi901965c.

Acknowledgements
This Publication is based oil work Financed by King Abdullah University of Science and Technology (KAUST) (Grant KUK-11008-23).

Publisher
American Chemical Society (ACS)

Journal
Biochemistry

DOI
10.1021/bi901965c

PubMed ID
20000803

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