Which motor protein interacts with actin to produce contraction?

Which motor protein interacts with actin to produce contraction?

• A. Myosin
• B. Actin
• C. Tropomyosin
• D. Nebulin

Answer: (A)

Contraction is driven when a motor protein uses energy from ATP to walk along actin filaments, pulling them and shortening the sarcomere. The motor protein that does this is myosin. Its heads bind to specific sites on actin, undergo a conformational change (the power stroke), and pull the actin filament past the myosin, causing sliding and overall muscle shortening. Actin forms the track, while tropomyosin regulates access to the binding sites and nebunlin (nebula) helps set thin-filament length. But only myosin provides the active force to contract the muscle by interacting with actin.

Contraction is driven when a motor protein uses energy from ATP to walk along actin filaments, pulling them and shortening the sarcomere. The motor protein that does this is myosin. Its heads bind to specific sites on actin, undergo a conformational change (the power stroke), and pull the actin filament past the myosin, causing sliding and overall muscle shortening. Actin forms the track, while tropomyosin regulates access to the binding sites and nebunlin (nebula) helps set thin-filament length. But only myosin provides the active force to contract the muscle by interacting with actin.