Structural dynamics of light-driven proton pumps.
Artikel i vetenskaplig tidskrift, 2009

Bacteriorhodopsin and proteorhodopsin are simple heptahelical proton pumps containing a retinal chromophore covalently bound to helix G via a protonated Schiff base. Following the absorption of a photon, all-trans retinal is isomerized to a 13-cis conformation, initiating a sequence of conformational changes driving vectorial proton transport. In this study we apply time-resolved wide-angle X-ray scattering to visualize in real time the helical motions associated with proton pumping by bacteriorhodopsin and proteorhodopsin. Our results establish that three conformational states are required to describe their photocycles. Significant motions of the cytoplasmic half of helix F and the extracellular half of helix C are observed prior to the primary proton transfer event, which increase in amplitude following proton transfer. These results both simplify the structural description to emerge from intermediate trapping studies of bacteriorhodopsin and reveal shared dynamical principles for proton pumping.

Författare

Magnus Andersson

Chalmers, Kemi- och bioteknik, Molekylär mikroskopi

Erik Malmerberg

Göteborgs universitet

Sebastian Westenhoff

Göteborgs universitet

Gergely Katona

Göteborgs universitet

Marco Cammarata

European Synchrotron Radiation Facility (ESRF)

Annemarie Wöhri

Chalmers, Kemi- och bioteknik, Molekylär mikroskopi

Linda C Johansson

Göteborgs universitet

Friederike Ewald

European Synchrotron Radiation Facility (ESRF)

Mattias Eklund

Uppsala universitet

Michael Wulff

European Synchrotron Radiation Facility (ESRF)

J Davidsson

Uppsala universitet

Richard Neutze

Göteborgs universitet

Structure (London, England : 1993)

1878-4186 (ISSN)

Vol. 17 1265-75

Ämneskategorier

Kemi

DOI

10.1016/j.str.2009.07.007

PubMed

19748347