FIG. 1.
Cryo-EM of HRV3-receptor complexes and uncoating intermediates. (A) Schematic view of the pathway of HRV3 uncoating mediated by soluble ICAM-1 binding (5) and the procedure used for preparation of virus-receptor complexes for cryo-EM. Arrows and hexagons represent the ICAM-1 receptor and the HRV particles, respectively. H3RC was prepared by incubation of HRV3 with ICAM-1 at 4°C, while H3RH and H3Re were prepared at 37°C as described in Materials and Methods. H3RC and H3RH preserve all viral proteins and RNA, while H3Re lacks both VP4 and RNA (5). (B) Micrograph of H3RC. (C) Micrograph of H3RH and H3Re complexes. About 40% of the particles appear empty (H3Re), lacking the internal RNA genome represented by a spiral line in panel A. Bar, 1,000 Å.