Abstract

Understanding how chemical energy is converted into directed movement is a fundamental problem in biology. In higher organisms this is accomplished through the hydrolysis of ATP by three families of motor proteins: myosin, dynein and kinesin. The most abundant of these is myosin, which operates against actin and plays a central role in muscle contraction. As summarized here, great progress has been made towards understanding the molecular basis of movement through the determination of the three‐dimensional structures of myosin and actin and through the establishment of systems for site‐directed mutagenesis of this motor protein. It now appears that the generation of movement is coupled to ATP hydrolysis by a series of domain movements within myosin.