Fig. 4.

Structural comparison of the catalytic domain of Clostridium perfringens NanI (CpNanI_CD) with human neuraminidases. Stereoview of the superimposed structure of CpNanI_CD with CHES (cyan) and catalytic domains of human Neu2 (PDB code 1VCU, brown), Neu1 (green), Neu3 (pink), and Neu4 (yellow). The structures of human Neu1, Neu3, and Neu4 are modeled using human Neu2 as a template (see Materials and Methods). CHES, residues, and the water molecule (W1) are displayed as stick models and a sphere, respectively. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)