Figure 2.

The novel complex structure between SpNanA and Neu5Ac9N₃2en (2). There are two subunits. A (red) and B (blue) in an asymmetric unit shown in the up panel. The bound Neu5Ac9N₃2en molecules in subunits A and B are shown in light blue and pink sticks, respectively. The close up views of Neu5Ac9N₃2en binding sites in subunits A (left) and B (right) are shown in the lower panel. The side chains of amino acid residues involving in the hydrogen bond interactions with Neu5Ac9N₃2en are shown in green sticks. Potential hydrogen bond interactions between the Neu5Ac9N₃2en and the protein are shown in red dashed lines.