Fig. 4.

Conserved surfaces on the human astrovirus projection domain. (A) Multiple sequence alignment of the projection domains (residues 415–646 for serotype 8) from human astroviruses of the eight different serotypes. The level of conservation is color-coded by different shades of white (least conserved) and blue (strictly conserved). The multiple sequence alignment was computed using ALINE (41). (B and C) Astrovirus projection domain, viewed from the side and the top, respectively. Residues in one subunit are colored according to their levels of conservation. The other subunit is colored in gray. Three highly conserved sites are delineated by dotted black curves. (D) Stereo view of the putative receptor-binding site (P site).