Figure 1.

Receptor-binding sites on the globular domains of NDV HN and MV H. The outlines of the top views of the dimeric forms of (a) NDV HN and (b) MV H (looking down at the molecule from the target membrane) are shown. (a) Made in RASMOL from coordinates published by Zaitsev et al. [6]. (b) Made from the dimer published by Hashiguchi et al. [13]. Labeled ovals represent the locations of the two sialic acid-binding sites in (a) NDV HN and the CD46- and SLAM-binding sites in (b) MV H.