Regensburg 2010 – wissenschaftliches Programm
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BP: Fachverband Biologische Physik
BP 7: Posters: Biological Machines, Motor Proteins
BP 7.8: Poster
Montag, 22. März 2010, 17:15–20:00, Poster B1
Functional Rotation of the Transporter AcrB: The Essentials of Peristaltic Motion and Subsequent Substrate Extrusion — •Robert Schulz1, Attilio Vittorio Vargiu2, Michael Schreiber3, Paolo Ruggerone2, and Ulrich Kleinekathöfer1 — 1School of Engineering and Science, Jacobs University Bremen, Germany — 2SLACS & Department of Physics, University of Cagliari, Italy — 3Institut für Physik, Technische Universität Chemnitz, Germany
The RND transporter of E. coli’s multidrug efflux pump AcrAB-TolC is able to export structurally and chemically different, toxic substrates, including antibiotics, via a functional rotation. The three major states of this rotation cycle were found in several assymmetric crystal structures. After initially analyzing the basic mechanisms of opening of the TolC channel [1] and of substrate extrusion by AcrB [2] separately, we have continued the analysis of the latter one. Thereby, we have focused both on the local interactions between substrate and protein, the properties of the extrusion pathway, as well as the principal subdomain movements which lead to the peristaltic motion. Furthermore, we have investigated the possibility to pull the substrate from the final state of the previous simulations out of the exit gate to estimate whether the substrate is already free to leave the protein via diffusion, which is usually beyond the time scale of computer simulations.
[1] R. Schulz, U. Kleinekathöfer, Biophys. J. 96, 3116 (2009)
[2] R. Schulz, A.V. Vargiu, F. Collu, U. Kleinekathöfer, P. Ruggerone, submitted