Fig. 2.

Hexagonal assemblies of TRIM5-21R. (A) Representative negatively-stained EM image of a hexagonal array formed spontaneously by dimeric TRIM5-21R upon incubation on a carbon-coated grid. (Scale bar,100 nm). The red circle demarcates a region with clear hexagonal order, as shown in the computed Fourier transform (inset). (B) Fourier-filtered image of a TRIM5-21R array preserved in vitreous ice. (C) Projection density map of (B) shown in gray scale (with no imposed symmetry), illustrating that the hexagonal lattice is composed of six-sided rings. The unit cell parameters for the crystals are: (A) a = 347 Å, b = 335 Å, γ = 119.3°; (B) and (C) a = 348 Å, b = 346 Å, and γ = 120.5°.