The dimer interface of PEG3-SCAN (I).

<p>A hydrogen-bonding network is formed between conserved residues lining the subunit-subunit interface. Water molecules are shown as red spheres, N and O positions are colored blue and red respectively, C positions are purple or green depending on the subunit to which they belong, hydrogen bonds are depicted as dashed lines. The same color scheme is used in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0069538#pone-0069538-g006" target="_blank">Figures 6</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0069538#pone-0069538-g007" target="_blank">7</a> and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0069538#pone-0069538-g008" target="_blank">8</a>.