The neck region of the myosin motor domain acts as a lever arm to generate movement.

Abstract

The myosin head consists of a globular catalytic domain that binds actin and hydrolyzes ATP and a (Fig. 1 Upper). Depending on the magnitude of the angle change, the swinging motion of the -8-nm-long lever arm could produce a displacement of similar size, in keeping with 4-to 10-nm steps directly measured (6-9).Electron microscopy has successfully observed two different shapes of the head in a way that is consistent with this model (10). Physical measurements have also supported this hypothesis by demonstrating a cyclic change in gyratory radius of the head during ATP hydrolysis cycles (11,12). Recently, 3-D helical reconstruction of actin decorated with myosin heads revealed a swinging motion of the neck region associated with release of ADP from the catalytic domain, resulting in 3-toThe publication costs of this article were defrayed in part by page charge payment. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. §1734 solely to indicate this fact.

Molecular mechanism regulating myosin and cardiac functions by ELC

“…There was no distinction in life time of all binding events. Besides the lever arm [24], the converter domain was suggested to represent an alternative element of elastic distortion during force generation [25]. A FHC-related mutation within the converter domain substantially decreased myosin stiffness in fibers [26,27].…”

Kinesin motors as molecular machines

“…(53) The movement might represent a lever arm-like angle change of the coiled-coil stalk/ neck of Ncd, similar to the large rotation of the coiled-coil rod believed to occur in myosin. (55)(56)(57) A second displacement has been detected just before release of Ncd from the microtubule and has been postulated to be the large conformational change predicted to occur when ATP binds to the motor. (54) The structural basis of this movement has not yet been determined, although it may correspond to the rotation coupled to a translation of the relay helix, a4, detected in the kinesin motor KIF1A, which is thought to be triggered by binding of ATP to the motor.…”

Role of Dictyostelium racE in cytokinesis: mutational analysis and localization studies by use of green fluorescent protein.

“…These and all following constructs were cloned into the expression vector pTIKL-Bsr-Exp. This vector is based on the extrachromasomal vector pTIKL (Uyeda et al, 1996), We replaced the G418 resistance gene of pTIKL with a blasticidin (Bsr) resistance gene (Sutoh, 1993). We also introduced an actinl5 promoter expression cassette for expression of the various rac constructs.…”