No strain, no gain

Abstract

Myosin-V transports intracellular cargo along an actin filament, using a 'hand-over-hand' mechanism that moves it forward in 36-nm steps before dissociating. To achieve long run lengths, the stepping of the two myosin heads must be coordinated. Recent evidence favours the idea that this coordination is achieved by intramolecular strain between the heads, so that myosin prefers to pick up its trailing head first to search for a new actin-binding site, and move cargo forward on the actin. © 2005 Nature Publishing Group.