Related Experiment Video
Updated: Nov 23, 2025

Probing Myosin Ensemble Mechanics in Actin Filament Bundles Using Optical Tweezers
Published on: May 4, 2022
Modulation of post-powerstroke dynamics in myosin II by 2'-deoxy-ADP
Matthew Carter Childers1, Michael Geeves2, Valerie Daggett1
1Department of Bioengineering, University of Washington, Seattle, WA, 98195-5013, USA.
Abstract:
Muscle myosins are molecular motors that hydrolyze ATP and generate force through coordinated interactions with actin filaments, known as cross-bridge cycling. During the cross-bridge cycle, functional sites in myosin 'sense' changes in interactions with actin filaments and the nucleotide binding region, resulting in allosteric transmission of information throughout the structure. We investigated whether the dynamics of the post-powerstroke state of the cross-bridge cycle are modulated in a nucleotide-dependent fashion. We compared molecular dynamics simulations of the myosin II motor domain (M) from Dictyostelium discoideum in the presence of ADP (M.ADP) versus 2'-deoxy-ADP bound myosin (M.dADP). We found that dADP was more flexible than ADP and the two nucleotides interacted with myosin in different ways. Replacement of ADP with dADP in the post-powerstroke state also altered the conformation of the actin binding region in myosin heads. Our results provide atomic level insights into allosteric communication networks in myosin that provide insight into the nucleotide-dependent dynamics of the cross-bridge cycle.
Related Concept Videos
Overview of Myosin Structure and Function
ATP Synthase: Structure
ATP Driven Pumps II: P-type Pumps
A typical P-type pump has three cytosolic domains: nucleotide-binding (N), phosphorylation (P), and activator (A) domains. These domains are connected to the membrane-spanning helices by short amino acid segments. ATP hydrolysis and covalent phosphoenzyme intermediate formation are crucial parts of the catalytic cycle. At the highly...
Actin and Myosin in Muscle Contraction
ATP Synthase: Mechanism
Cross-bridge Cycle

