Dave Thirumalai
Department of Chemistry& Biochemistry and
Institute for Physical Science and Technology
University of Maryland

Stepping kinetics of Myosin motors: Moving forward, Backward, and foot Stomping

Myosin V, two-headed motor protein, ferries cellular cargo by walking hand-over-hand on actin filaments.  Interplay between ATD-driven conformational changes in the motor head and stress due to load produces a variety of stepping dynamics: the motor can step forward or backward, or "stomp", where one of the heads detaches and rebinds to the same site.  I will present theory that captures all these behaviors, quantitatively matching a wide array of single molecule experiments.  The theory lays out the structural and chemical design principles underlying the motor's robust function, which provides a guide for how bioengineering might alter its dynamics [1]. The theoretical results will be complemented with simulations describing the role the internal dynamics of the motor domain plays in motility [2].

References:

[1] M. Hinczewski, R. Tehver, and D. Thirumalai, Proc. Natl. Acad. Sci. 110: E4059-E4068, (2013).

[2] R. Tehver and D. Thirumalai, Structure, 18: 471-481, (2010).