Travel and Contact  Staff Only  Site Map  Help?     EMBL Hamburg > Courses and Conferences   Invitation   Poster   Speakers   Sponsors   Organisers   Programme   Pictures      16 September      15 September      PDB Exhibition   Kenneth C. Holmes - 50 years ago the sliding filament theory established that during muscle contraction the actin and myosin filaments of muscle move past each other. This motion is driven by the hydrolysis of adenosine triphosphate (ATP). The motors that produce the sliding have been shown to be the "myosin cross-bridges", parts of the myosin molecule that project sideways from the thick (myosin) filaments and interact cyclically with the thin (actin) filaments. The cross bridges consist of a "motor domain" containing the ATP and actin binding sites, and a long lever arm that rotates during the binding and hydrolysis of ATP. On binding to actin this rotation is reversed (the power stroke) and the products of hydrolysis are released. Thus the cross-bridge "rows" the actin filament along. The rebinding of ATP leads to a rapid release of the cross-bridge from the actin filament so as to start a new cycle. Most of these processes can now be described in atomic detail.