Andrij Baumketner: On leave from the Institute for Condensed Matter Physics, NAS of Ukraine, 1 Svientsistsky Str, Lviv, 79011 Ukraine.
The mechanism of the converter domain rotation in the recovery stroke of myosin motor protein†
Article first published online: 15 SEP 2012
Copyright © 2012 Wiley Periodicals, Inc.
Proteins: Structure, Function, and Bioinformatics
Volume 80, Issue 12, pages 2701–2710, December 2012
How to Cite
Baumketner, A. (2012), The mechanism of the converter domain rotation in the recovery stroke of myosin motor protein. Proteins, 80: 2701–2710. doi: 10.1002/prot.24155
- Issue published online: 1 NOV 2012
- Article first published online: 15 SEP 2012
- Accepted manuscript online: 31 JUL 2012 09:17PM EST
- Manuscript Accepted: 16 JUL 2012
- Manuscript Revised: 6 JUL 2012
- Manuscript Received: 16 MAR 2012
- National Institutes of Health. Grant Numbers: R01GM083600-04, 1S10RR026514-01
- recovery stroke;
- computer simulation;
- converter domain;
Upon ATP binding, myosin motor protein is found in two alternative conformations, prerecovery state M* and postrecovery state M**. The transition from one state to the other, known as the recovery stroke, plays a key role in the myosin functional cycle. Despite much recent research, the microscopic details of this transition remain elusive. A critical step in the recovery stroke is the rotation of the converter domain from “up” position in prerecovery state to “down” position in postrecovery state that leads to the swing of the lever arm attached to it. In this work, we demonstrate that the two rotational states of the converter domain are determined by the interactions within a small structural motif in the force-generating region of the protein that can be accurately modeled on computers using atomic representation and explicit solvent. Our simulations show that the transition between the two states is controlled by a small helix (SH1) located next to the relay helix and relay loop. A small translation in the position of SH1 away from the relay helix is seen to trigger the transition from “up” state to “down” state. The transition is driven by a cluster of hydrophobic residues I687, F487, and F506 that make significant contributions to the stability of both states. The proposed mechanism agrees well with the available structural and mutational studies. Proteins 2012; © 2012 Wiley Periodicals, Inc.