[Myosin head structure].

The current data and concepts of the structural organization of the head of myosin, one of the major muscle proteins, are reviewed. The primary structure of the isolated myosin head (myosin subfragment-1) heavy chain and localization in it of sites and groups responsible for the binding and hydrolysis of ATP and myosin interaction with actin, are considered. Evidence is given of reciprocal spatial distribution of these sites and their localization on the myosin head surface. Some present-day concepts on the domain organization of the myosin head and its changes occurring during binding and hydrolysis of ATP, are discussed. A model describing the folding of the heavy and light chains in the myosin head is proposed.