Cryo-EM reconstruction of Cp183-Impβ complex in sodium chloride.

<p>(a) Representative cryo-EM micrograph of Cp183 capsid (11 μM dimer) and 18.8 μM Impβ, a ratio of 205 importins per capsid, in 0.15 M NaCl. Most particles appear to be empty (white arrow), but some dark particles (black arrow), T = 3 particles (black arrowhead), and defective particles (star) were observed. (b) The central sections of the 3D reconstructions, computed from all particles (left) and the dark particles (right), show an internal dark ring of density. Oval, triangle, and pentagon indicate locations of twofold, threefold and fivefold axes, respectively. The reconstructions were determined to 8.9 Å resolution for all particles and 15.9 Å resolution for the dark particles.