Evidence and sources

Measurements

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Big picture numbers

Structures

• 5H53
  Muscle myosin head on actin, rigor

  The classic muscle cross-bridge: a complete head with both light chains, bound to actin at the end of the stroke. Electron microscopy, 5.2 Å.
• 8R9V
  Myosin-5a on actin, primed

  The first view of a primed head on actin, caught 10 ms after mixing. Start of the power-stroke morph. Electron microscopy, 4.4 Å.
• 8RBF
  Myosin-5a on actin, after the stroke

  End of the power-stroke morph, captured 120 ms after mixing. Same actin frame as 8R9V. Electron microscopy, 4.2 Å.
• 7PLT
  Myosin-Va on actin, rigor, 3.3 Å

  Highest-resolution rigor actomyosin here, with a light chain on the lever. Use it for the tight actin interface. Electron microscopy, 3.3 Å.
• 1QVI
  Scallop head, pre-power stroke

  Primed head with both light chains. Start of the lever-swing morph on the complete head. X-ray diffraction, 2.54 Å.
• 1KK7
  Scallop head, near-rigor

  End of the lever-swing morph on the complete head. Same chain names as 1QVI. X-ray diffraction, 3.2 Å.
• 1KK8
  Scallop head, detached ATP-like

  An actin-detached state with ATP analogue bound. Morph it into 1QVI to show the recovery stroke that re-primes the lever. X-ray diffraction, 2.3 Å.
• 8A2T
  Actin filament, 2.2 Å

  The track. Its helical parameters (see geometry) let the scene extend a filament of any length. Electron microscopy, 2.24 Å.
• 8QYU
  Cardiac myosin with omecamtiv mecarbil

  Heart drug that activates myosin. The entry cites a 2023 bioRxiv preprint; the doi given is the published 2024 paper. X-ray diffraction, 1.96 Å.
• 8QYQ
  Cardiac myosin with mavacamten

  The approved inhibitor in the same pocket as the activator. Toggle 8QYU and 8QYQ to compare the two drugs. X-ray diffraction, 2.61 Å.
• 1OE9
  Myosin V head, rigor-like crystal

  The processive myosin that walks 36-37 nm hand-over-hand. Its cleft is closed and the lever sits in the rigor position without actin. X-ray diffraction, 2.05 Å.
• 2V26
  Myosin VI motor, pre-power stroke

  The reverse-direction myosin at the start of its stroke. Its converter rearranges, which enlarges the stroke. X-ray diffraction, 1.75 Å.
• 2BKH
  Myosin VI motor with insert-2 and calmodulin

  Shows the insert and calmodulin that point the myosin VI lever backwards. This is the structural basis of its minus-end motion. X-ray diffraction, 2.4 Å.
• 8EFI
  Human cardiac myosin on a thin filament, rigor

  The heart motor bound to a regulated thin filament. Myosin loop 4 touches tropomyosin here. Electron microscopy, 3.4 Å.

References

1. 1Klebl et al., Nature 2025. Swinging lever mechanism of myosin directly shown by time-resolved cryo-EM
2. 2Pospich et al., eLife 2021. High-resolution structures of the actomyosin-V complex in three nucleotide states provide insights into the force generation mechanism
3. 3Fujii et al., Nat Commun 2017. Structure of actomyosin rigour complex at 5.2 Å resolution and insights into the ATPase cycle mechanism
4. 4Gourinath et al., Structure 2003. Crystal Structure of Scallop Myosin S1 in the Pre-Power Stroke State to 2.6 Å Resolution
5. 5Himmel et al., PNAS 2002. Crystallographic findings on the internally uncoupled and near-rigor states of myosin: Further insights into the mechanics of the motor
6. 6Houdusse et al., Cell 1999. Atomic Structure of Scallop Myosin Subfragment S1 Complexed with MgADP
7. 7Houdusse et al., PNAS 2000. Three conformational states of scallop myosin S1
8. 8Auguin et al., Nat Commun 2024. Omecamtiv mecarbil and Mavacamten target the same myosin pocket despite opposite effects in heart contraction
9. 9Planelles-Herrero et al., Nat Commun 2017. Mechanistic and structural basis for activation of cardiac myosin force production by omecamtiv mecarbil
10. 10Winkelmann et al., Nat Commun 2015. Structural basis for drug-induced allosteric changes to human β-cardiac myosin motor activity
11. 11Oosterheert et al., Nature 2022. Structural basis of actin filament assembly and aging
12. 12Nakamura et al., Nat Nanotechnol 2014. Remote control of myosin and kinesin motors using light-activated gearshifting
13. 13Hess et al., Rev Mol Biotechnol 2001. Molecular shuttles based on motor proteins: active transport in synthetic environments
14. 14Saper et al., Chem Rev 2020. Synthetic Systems Powered by Biological Molecular Motors
15. 15Furuta et al., Nat Nanotechnol 2017. Creating biomolecular motors based on dynein and actin-binding proteins
16. 16Kull et al., Nature 1996. Crystal structure of the kinesin motor domain reveals a structural similarity to myosin
17. 17Kikkawa et al., Nature 2001. Switch-based mechanism of kinesin motors
18. 18Vale et al., J Cell Biol 1996. Switches, latches, and amplifiers: common themes of G proteins and molecular motors
19. 19Uyeda et al., PNAS 1996. The neck region of the myosin motor domain acts as a lever arm to generate movement
20. 20Yildiz et al., Science 2003. Myosin V Walks Hand-Over-Hand: Single Fluorophore Imaging with 1.5-nm Localization
21. 21Mehta et al., Nature 1999. Myosin-V is a processive actin-based motor
22. 22Wells et al., Nature 1999. Myosin VI is an actin-based motor that moves backwards
23. 23Ménétrey et al., Nature 2005. The structure of the myosin VI motor reveals the mechanism of directionality reversal
24. 24Ménétrey et al., Cell 2007. The Structural Basis for the Large Powerstroke of Myosin VI
25. 25Finer et al., Nature 1994. Single myosin molecule mechanics: piconewton forces and nanometre steps
26. 26De La Cruz et al., PNAS 1999. The kinetic mechanism of myosin V
27. 27Howard et al., Nature 1997. Molecular motors: structural adaptations to cellular functions
28. 28Rayment et al., Science 1993. Structure of the actin-myosin complex and its implications for muscle contraction
29. 29Coureux et al., Nature 2003. A structural state of the myosin V motor without bound nucleotide
30. 30Tsiavaliaris et al., Nature 2004. Molecular engineering of a backwards-moving myosin motor
31. 31Chen et al., Nat Nanotechnol 2012. Engineering controllable bidirectional molecular motors based on myosin
32. 32Schindler et al., Nat Nanotechnol 2014. Engineering myosins for long-range transport on actin filaments
33. 33Malik et al., Science 2011. Cardiac Myosin Activation: A Potential Therapeutic Approach for Systolic Heart Failure
34. 34Green et al., Science 2016. A small-molecule inhibitor of sarcomere contractility suppresses hypertrophic cardiomyopathy in mice
35. 35Foth et al., PNAS 2006. New insights into myosin evolution and classification
36. 36Odronitz et al., Genome Biol 2007. Drawing the tree of eukaryotic life based on the analysis of 2,269 manually annotated myosins from 328 species
37. 37Anson et al., EMBO J 1996. Myosin motors with artificial lever arms
38. 38Rief et al., PNAS 2000. Myosin-V stepping kinetics: a molecular model for processivity