Proceedings of the National
of Sciences USA, vol. 102,
|The Lymn-Taylor contraction cycle.
The recovery-stroke is between states II and III: the lever arm (in yellow) attached to the converter domain (in green) swings back to prepare for the next power-stroke.
|The two end-state structures
of the recovery-stroke.
The converter domain (in green) rotates by ~60 degrees to swing the lever-arm (in yellow). It is 40Angstroem away from the ATP (in van der Waals spheres). The converter-domain orientation must be coupled to the conformation of the relay helix (in cyan) near the ATP in such a way that ATPase activity is switched on only when the Lymn-Taylor cycle is in state III.
Movie 1. Overall view (Fig1 B&C of
Overall view showing the recovery stroke of Myosin. The converter domain (green) and the lever-arm (yellow) are seen to rotate ~65 degrees relative to the main body of myosin (orange). After the end of this movie, the actin fibril (not shown) comes from the right side and re-binds to the main body for the power stroke. The movie frames are made from coordinate sets taken from the minimum energy path (MEP) computed by Conjugate Peak Refinement (CPR), as described in the paper. Here, only the protein backbone (colored as in Figure 1B&C) and the bound ATP (in van der Waals) are shown. File size 1Mb.
Download the movie (Low-res. version, 1Mb, as in PNAS suppl. materials)
Download the movie (High-res. version, 2.8Mb)
Same as movie 1, but showing all the atoms used in the calculation.
Download the movie (Large file, 12Mb, as in PNAS suppl. materials)
Movie 3. Hinging of the converter domain
Fig.2-left of paper).
Motions described in Figure 2. As movie 1, but different view (down the SH1-helix, in purple) showing the converter domain (green) and the lever-arm (yellow) rotating ~65 degrees relative to the main body of myosin (orange), around an axis close to the axis of the SH1-helix. Shows the hinging point of the converter domain on the SH1-helix, and the linkage between the converter domain and the C-terminus of the relay helix (in cyan).
Download the movie (Low-res. version, 1.5Mb, as in PNAS suppl. materials)
Download the movie (High-res. version, 5Mb)
Movie 4. Seesaw and local unwinding of the
relay helix (see
Motions described in Figure 2 (same view and coloring as in movie 1). Shows how the closing of the Switch2 loop (orange) over the bound ATP (van der Waals) is coupled to a large translation of the C-terminus of the relay helix (cyan), which accompanies the rotation of the converter domain (of which a small piece is shown in green). To accomodate this rotation, the C-terminal third of the relay helix undergoes an unwinding by 1/8th turn, breaking the helical H-bond at residue 486. As a result of the unwinding, the aromatic ring of Phe487 (orange) reorients and must thread between the relay helix and the relay loop (in white).
Download the movie (Low-res. version, 0.7Mb, as in PNAS suppl. materials)
Download the movie (High-res. version, 8.5Mb)
Go to Home of S. Fischer