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Research article - Peer-reviewed, 2004

Deformation of helix C in the low temperature L-intermediate of bacteriorhodopsin

Edman K, Royant A, Larsson G, Jacobson F, Taylor T, van der Spoel D, Landau EM, Pebay-Peyroula E, Neutze R


X-ray and electron diffraction studies of specific reaction intermediates, or reaction intermediate analogues, have produced a consistent picture of the structural mechanism of light-driven proton pumping by bacteriorhodopsin. Of central importance within this picture is the structure of the L-intermediate, which follows the retinal all-trans to 13-cis photoisomerization step of the K-intermediate and sets the stage for the primary proton transfer event from the positively charged Schiff base to the negatively charged Asp-85. Here we report the structural changes in bacteriorhodopsin following red light illumination at 150 K. Single crystal microspectrophotometry showed that only the L-intermediate is populated in three-dimensional crystals under these conditions. The experimental difference Fourier electron density map and refined crystallographic structure were consistent with those previously presented (Royant, A., Edman, K., Ursby, T., Pebay-Peyroula, E., Landau, E. M., and Neutze, R. ( 2000) Nature 406, 645 - 648; Royant, A., Edman, K., Ursby, T., Pebay- Peyroula, E., Landau, E. M., and Neutze, R. ( 2001) Photochem. Photobiol. 74, 794 - 804). Based on the refined crystallographic structures, molecular dynamic simulations were used to examine the influence of the conformational change of the protein that is associated with the K-to-L transition on retinal dynamics. Implications regarding the structural mechanism for proton pumping by bacteriorhodopsin are discussed

Published in

Journal of Biological Chemistry
2004, volume: 279, number: 3, pages: 2147-2158

Authors' information

Taylor, Tom
Swedish University of Agricultural Sciences, Department of Molecular Biology
Edman, K
Jacobson, F
Landau, EM
Larsson, G
Pebay-Peyroula, E
Royant, A
va der Spoel, D
Neutze, R

UKÄ Subject classification

Food Science
Agricultural Science
Environmental Sciences related to Agriculture and Land-use

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