Figure 4.
Panel A shows an electron micrograph of polymerized NM 2A1933X, displaying filament structures. Panel B shows an electron micrograph of polymerized NM 2A1945X, also displaying filament structures. Panel C shows an electron micrograph of polymerized NM 2A2NHT, displaying filament structures. Panel D shows an electron micrograph of polymerized NM 2A-AM1Ct, displaying filament structures. Panel E shows electron micrographs of individual filaments of these NM 2A NHT variants. Panel F contains three graphs plotting filament dimensions of wild-type NM 2A and its NHT variants against the total number of amino acids in their NHTs. The left graph shows filament length in nanometers, the middle graph shows filament width in nanometers, and the right graph shows filament bare zone length in nanometers. Each graph includes data points for different NM 2A variants, with error bars indicating standard deviation.
NHT length as a major determinant of NM-IIA filament size. (A–D) Electron micrographs of polymerized NM-IIA1933X (A), NM-IIA1945X (B), NM-IIA2NHT (C), and NM-IIA-AM1Ct (D). (E) Individual filaments of these NM-IIA NHT variants in higher magnification. Myosins were polymerized under the same conditions as in Fig. 1. (F) Filament dimensions of WT NM-IIA and its NHT variants plotted against the total number of aa in their NHTs. Filament dimensions were measured from electron micrographs (Figs. 1 and 4) using MetaMorph. Data are presented as the mean ± SD.