TCB Publications - Abstract

TCB Publications - Abstract

Ulrich Kleinekathoefer, Barry Isralewitz, Markus Dittrich, and Klaus Schulten. Domain motion of individual F1-ATPase β-subunits during unbiased molecular dynamics simulations. Journal of Physical Chemistry, 115:7267-7274, 2011. (PMC: 3121902)

KLEI2011 F$_1$-ATPase is the catalytic domain of F$_1$F$_{\rm o}$-ATP synthase and consists of an hexameric arrangement of three non-catalytic $\alpha$ and three catalytic $\beta$ subunits. We have used molecular dynamics simulations with a total simulation time of 900 ns to investigate the dynamic equilibrium properties of isolated $\beta$-subunits as a step toward explaining the function of the integral F$_1$ unit. To this end, we equilibrated the open ($\beta_E$) and the closed ($\beta_{TP}$) conformations for up to 120 ns each using several samples. The simulations confirm that nucleotide-free $\beta_E$ retains its open configuration over the course of the simulations. The same is true when the neighbouring $\alpha$ subunits are included. The nucleotide-depleted as well as the nucleotide-bound isolated $\beta_{TP}$ subunits show a significant trend toward the open conformation during our simulations, with one trajectory per case opening completely. Hence, our simulations suggest that the equilibrium conformation of a nucleotide-free $\beta$- subunit is the open conformation and that the transition from the closed to the open conformation can occur on a timescale of a few tens of nanoseconds.


Download Full Text

The manuscripts available on our site are provided for your personal use only and may not be retransmitted or redistributed without written permissions from the paper's publisher and author. You may not upload any of this site's material to any public server, on-line service, network, or bulletin board without prior written permission from the publisher and author. You may not make copies for any commercial purpose. Reproduction or storage of materials retrieved from this web site is subject to the U.S. Copyright Act of 1976, Title 17 U.S.C.

Download full text: Journal, Request a Copy