[Conformational transitions in myosin cross-bridges during the mechanochemical act]

The investigations of the molecular bases of muscle contraction posed the following question: in which part of the myosin cross-bridge, the head or the fibrillar part, the conformational changes occur that lead to the generation of force. The paper deals with experimental and theoretical data that are in some way related to the solution of this question. Based on the analysis of recent data, an alternative pattern of ATP hydrolysis-coupled structural alternations in the myosin bridge during the mechanochemical act is proposed.