High-resolution structures of the actomyosin-V complex in three nucleotide states provide insights into the force generation mechanism

Elife. 2021 Nov 23;10:e73724. doi: 10.7554/eLife.73724.

Abstract

The molecular motor myosin undergoes a series of major structural transitions during its force-producing motor cycle. The underlying mechanism and its coupling to ATP hydrolysis and actin binding are only partially understood, mostly due to sparse structural data on actin-bound states of myosin. Here, we report 26 high-resolution cryo-EM structures of the actomyosin-V complex in the strong-ADP, rigor, and a previously unseen post-rigor transition state that binds the ATP analog AppNHp. The structures reveal a high flexibility of myosin in each state and provide valuable insights into the structural transitions of myosin-V upon ADP release and binding of AppNHp, as well as the actomyosin interface. In addition, they show how myosin is able to specifically alter the structure of F-actin.

Keywords: AppNHp; actin; actomyosin; chicken; cryo-EM; cytoskeleton; human; molecular biophysics; myosin; rabbit; structural biology.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actins / metabolism
  • Actomyosin / ultrastructure*
  • Animals
  • Biomechanical Phenomena
  • Chickens
  • Humans
  • Myosin Type V / ultrastructure*
  • Protein Binding
  • Rabbits

Substances

  • Actins
  • Actomyosin
  • Myosin Type V