Asymmetric Structure of a Virus-Receptor Complex
(A) A view perpendicular to the long axis of the pilus. MS2 is shown as a radially colored density at 1.3 σ; the surface of the virion is gray, but depressions in that surface are indicated by a blue coloration. The pilus is gold. The fitted X-ray structure for MS2, colored as in Figure 1, is shown on the left of the virion. MS2 binds to pilus at a 9° angle indicated by the dashed line through the center of the particle.
(B) A view rotated by 90° to look down the long axis of the pilus.
(C and D) The same views as in (A) and (B) but at a higher contour level (2.1 σ), at which the connection between virion and pilus is only just maintained.
See also Figure S1.