The gated gait of the processive molecular motor, myosin V.

Abstract

Class V myosins are actin-based molecular motors involved in vesicular and organellar transport. Single myosin V molecules move processively along F-actin, taking several 36-nm steps for each diffusional encounter. Here we have measured the mechanical interactions between mouse brain myosin V and rabbit skeletal F-actin. The working stroke produced by a myosin V head is approximately 25 nm, consisting of two separate mechanical phases (20 + 5 nm). We show that there are preferred myosin binding positions (target zones) every 36 nm along the actin filament, and propose that the 36-nm steps of the double-headed motor are a combination of the working stroke (25 nm) of the bound head and a biased, thermally driven diffusive movement (11 nm) of the free head onto the next target zone. The second phase of the working stroke (5 nm) acts as a gate - like an escapement in a clock, coordinating the ATPase cycles of the two myosin V heads. This mechanism increases processivity and enables a single myosin V molecule to travel distances of several hundred nanometres along the actin filament.

• Authors: Claudia Veigel, Fei Wang, Marc L Bartoo, James R Sellers, Justin E Molloy
• Journal: Nature cell biology (Nat Cell Biol) Vol. 4 Issue 1 Pg. 59-65 (Jan 2002) ISSN: 1465-7392 [Print] England
• PMID: 11740494 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Actins
• Molecular Motor Proteins
• Recombinant Proteins
• Adenosine Triphosphate
• Myosin Type V

Topics

• Actins (chemistry, metabolism)
• Adenosine Triphosphate (metabolism)
• Animals
• Brain (metabolism)
• Hydrolysis
• Mice
• Models, Molecular
• Molecular Motor Proteins
• Muscle, Skeletal (metabolism)
• Myosin Type V (chemistry, metabolism)
• Rabbits
• Recombinant Proteins (chemistry, metabolism)