Figure 3. Electron cryomicrographs of the polyrod and polyhook and their Fourier transforms.

(a) CryoEM image of frozen-hydrated polyrods. (b) CryoEM of frozen-hydrated polyhooks, which were made straight by incubating them at 4°C. Scale bars: 200 Å. (c) Averaged Fourier transform of the polyrod computed from ∼3,000 image segments of 524 Å in length. Four layer lines are labelled with their Bessel orders. The positions of these layer lines are: 1-start, 24.0 Å⁻¹; 5-start, 41.0 Å⁻¹; 6-start, 52.2 Å⁻¹; 11-start, 192 Å⁻¹. (d) A Fourier transform of the polyhook computed from a single image segment. The layer line positions are almost the same as those of the polyrod.