The corrected layer line intensities and the thick myosin filament model.

(A) Comparison of the corrected layer line intensities (gray curves) from nearly full-overlap muscles and the intensities calculated from the optimum model with the azimuthal perturbations and C-proteins (the full-filament overlap model) (black curves). The intensities indicated by dashed lines in the region of R<0.0254 nm⁻¹ are not used for modeling (see text). The intensities are normalized as in Fig. 4B. (B) Part of the radial projection of the crossbridge helices of a myosin filament in the perturbed region showing the azimuthal locations of crowns 1, 2, 3 and 4 and the displacements due to the axial and azimuthal perturbations. The abscissa axis is denoted by φ instead of 0∼2πr. Blue filled circles and black open circles denote respectively the shifted and regular locations of the crossbridge centers along the three 9/1 helical lines. Each dashed line shows each 9/1 helix in the three-stranded regular helical filament. (C) and (D) The full-filament overlap models in projection view in the regular (C) and perturbed (D) regions. (E) and (F) Those in cross-sectional view at the axial level of crown 2 in the regular (E) and perturbed (F) regions. (G) and (H) Those in side view in the regular (G) and perturbed (H) regions within the basic repeat. (I) and (J) Close-up views of the inter- and intra-molecular interactions between the myosin heads at the asterisk in (G) and (H). Yellow spheres mark the converter portion of the red head. The bottom of (G)-(J) is toward the M-line. The backbone is described as a structure-less cylinder. Scale bar, 10 nm.