HIV-1 Env glycan shields.
a Left panel: Sharpened 3.2-Å-resolution C3-symmetric cryo-EM map of SARS S 2P ectodomain52 visualized at a high contour level with disordered S1 receptor-binding and N-terminal domains extending out from the central core. Middle panel: Low-pass filtered (lpf) cryo-EM map of the glycoprotein visualised at a low conto