Figure 1 - full size

 

Figure 1.
Fig. 1. A molecular surface rendered image (42) of a tetrameric head of A/tern/Australia/G70C/75 N9 NA viewed from above the molecule. The active site residues interacting with the Neu5Ac moiety (twist-boat conformation) in the catalytic sites are show in green. The residues that interact with the Neu5Ac moiety (chair conformation) in the^ HB sites are colored yellow (conserved in all avian strains) and^ blue (conserved in N9 stains). (Inset) A magnified region (×1.6) in the vicinity of these two sites of one subunit, illustrating the deep pocket of the catalytic site and the flat surface of^ the HB site of the enzyme.