Does the S2 rod of myosin II uncoil upon two-headed binding to actin? A leucine-zippered HMM study.

Myosin II, like many molecular motors, is a two-headed dimer held together by a coiled-coil rod. The stability of the (S2) rod has implications for head-head interactions, force generation, and possibly regulation. Whether S2 uncoils has been controversial.