Figure 5.

Rotational correlation analysis of PR⁻ MuLV images. Sectors were extracted from PR⁻ MuLV that displayed a well defined track pattern. Image analysis revealed 56- to 64-fold rotational symmetry, corresponding to the repeat pattern for the striations in the track pattern (Right). This rotational symmetry gives a spacing between the ties on the tracks of 44 ± 4 Å, and the peak-to-peak separation of the tracks was also ≈44 Å. Note the variation in the radial thickness of the region between the tracks and the lipid envelope.