Myosin is an ATP-driven motor that works on actin filaments. Its head binds actin, releases phosphate and swings a lever arm. This swing is the power stroke. ATP binding then frees the head, and hydrolysis re-cocks the lever for the next cycle. Myosin classes share the head but differ in lever length, direction and time spent bound to actin.
- Where
- Thick filaments of muscle sarcomeres, and the actin networks in the cytoplasm of eukaryotic cells.
- Power
- Hydrolysis of ATP in the head. Actin binding triggers the release of phosphate and then ADP.
about 11 nm
Stroke per head, muscle myosin
25