Substrate-induced conformational change in bacterial complex I
Mamedova A, Holt P, Carroll J, Sazanov LA. 2004. Substrate-induced conformational change in bacterial complex I. Journal of Biological Chemistry. 279(22), 23830–23836.
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Journal Article
| Published
Author
Mamedova, Aygun A;
Holt, Peter J;
Carroll, Joe D;
Sazanov, Leonid AISTA ![](https://research-explorer.ista.ac.at/images/icon_orcid.png)
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Abstract
The mechanism coupling electron transfer and proton pumping in respiratory complex I (NADH-ubiquinone oxidoreductase) has not been established, but it has been suggested that it involves conformational changes. Here, the influence of substrates on the conformation of purified complex I from Escherichia coli was studied by cross-linking and electron microscopy. When a zero-length cross-linking reagent was used, the presence of NAD(P)H, in contrast to that of NAD+, prevented the formation of cross-links between the hydrophilic subunits of the complex, including NuoB, NuoI, and NuoCD. Comparisons using different cross-linkers suggested that NuoB, which is likely to coordinate the key iron-sulfur cluster N2, is the most mobile subunit. The presence of NAD(P)H led also to enhanced proteolysis of subunit NuoG. These data indicate that upon NAD(P)H binding, the peripheral arm of the complex adopts a more open conformation, with increased distances between subunits. Single particle analysis showed the nature of this conformational change. The enzyme retains its L-shape in the presence of NADH, but exhibits a significantly more open or expanded structure both in the peripheral arm and, unexpectedly, in the membrane domain also.
Publishing Year
Date Published
2004-05-28
Journal Title
Journal of Biological Chemistry
Acknowledgement
This work was supported by the Medical Research Council and by a Royal Society/North Atlantic Treaty Organization postdoctoral fellowship (to A. A. M.)
Volume
279
Issue
22
Page
23830 - 23836
IST-REx-ID
Cite this
Mamedova A, Holt P, Carroll J, Sazanov LA. Substrate-induced conformational change in bacterial complex I. Journal of Biological Chemistry. 2004;279(22):23830-23836. doi:10.1074/jbc.M401539200
Mamedova, A., Holt, P., Carroll, J., & Sazanov, L. A. (2004). Substrate-induced conformational change in bacterial complex I. Journal of Biological Chemistry. American Society for Biochemistry and Molecular Biology. https://doi.org/10.1074/jbc.M401539200
Mamedova, Aygun, Peter Holt, Joe Carroll, and Leonid A Sazanov. “Substrate-Induced Conformational Change in Bacterial Complex I.” Journal of Biological Chemistry. American Society for Biochemistry and Molecular Biology, 2004. https://doi.org/10.1074/jbc.M401539200.
A. Mamedova, P. Holt, J. Carroll, and L. A. Sazanov, “Substrate-induced conformational change in bacterial complex I,” Journal of Biological Chemistry, vol. 279, no. 22. American Society for Biochemistry and Molecular Biology, pp. 23830–23836, 2004.
Mamedova A, Holt P, Carroll J, Sazanov LA. 2004. Substrate-induced conformational change in bacterial complex I. Journal of Biological Chemistry. 279(22), 23830–23836.
Mamedova, Aygun, et al. “Substrate-Induced Conformational Change in Bacterial Complex I.” Journal of Biological Chemistry, vol. 279, no. 22, American Society for Biochemistry and Molecular Biology, 2004, pp. 23830–36, doi:10.1074/jbc.M401539200.