Wag the Tail: Structural Dynamics of Actomyosin Yale E Goldman  Cell  Volume 93, Issue 1, Pages 1-4 (April 1998) DOI: 10.1016/S0092-8674(00)81137-X

Figure 1 Proposed Structure of Chicken Skeletal Actomyosin Subfragment-1 in the Absence of ATP (Rayment et al. 1993). Five polymerized actin monomers are in aqua. The catalytic domain (CD) of the myosin head contains N-terminal 25 kDa (green), 50 kDa (red), and C-terminal 20 kDa (blue) peptides. A square outlines the active site illustrated in Figure 4. A heavy chain α helix (blue) is bound to the essential (ELC, yellow) and regulatory (RLC, purple) light chains. The diagram was prepared using GRASP with coordinates obtained from <http://indy.mpimf-heidelberg.mpg.de/∼michael/ftp.html>. Cell 1998 93, 1-4DOI: (10.1016/S0092-8674(00)81137-X)

Figure 4 Crystal Structures of Dictyostelium Myosin-II Fragments Bound to MgADP and Either Beryllium Fluoride (A) or Aluminum Fluoride (B) Nucleotides, blue; Be and Al, pink; F, yellow; Mg2+, green; hydrogen bonds, dashed lines. In (B), a water molecule coordinated in the apical position is aquamarine. Adapted from Rayment et al. 1996, using MOLSCRIPT with Dr. I. Rayment's assistance. Cell 1998 93, 1-4DOI: (10.1016/S0092-8674(00)81137-X)

Figure 2 An Hypothesis for Actomyosin Energy Transduction Blue helices are actin filaments, barbed end downward. Violet is myosin. Dashed outlines indicate mobility. Adapted from Barsotti et al. 1996, with permission. Cell 1998 93, 1-4DOI: (10.1016/S0092-8674(00)81137-X)

Figure 3 Tension (T) and an Orientation-Sensitive Signal (Q⊥) from Chicken Gizzard RLC Labeled with 6-acetamidotetramethylrhodamine and Exchanged into a Rabbit Skinned Muscle Fiber Amplitudes of length steps are listed on the right; half of the imposed sliding is assumed to strain the myosin head and the other half is taken up by filament compliance (coil spring). Yellow arrows and angles refer to probes in the myosin heads that tilt promptly in response to length steps. During quick tension recovery, Q⊥ increases for a small release indicating tilting toward 90° (B, dashed outline and red arrow), but decreases for the larger release indicating tilting away from 90° (C). (From Hopkins et al. 1998.) Cell 1998 93, 1-4DOI: (10.1016/S0092-8674(00)81137-X)