FIG. 3.

Ribbon diagram of the α-carbon trace of the Sabin 3 promoter (10), viewed from the front (A) and side (B) of the virion (in panel B, the outside is toward the top left of the image and the inside is toward the bottom right). The virus particle consists of 60 protomers, each containing a single copy of VP1, VP2, VP3, and VP4, arranged in icosahedral symmetry. The fivefold and threefold axes of symmetry and the canyon are labelled. Amino acid substitutions selected and maintained in sequential isolates from patient 222f are highlighted. The location of sphingosine (SPH) in the hydrocarbon-binding pocket is also indicated.