<p>(A) Cartoon representation of structural models from the <i>Eg</i>KUs and the crystal structure of α-DTX (1DTX) featuring solvent-accessible (> 40 Å<sup>2</sup>) aromatic (purple), acid (red) and basic (blue) residues. N and C terminal ends are labeled. Note the presence of patches of basic amino acids with close aromatic residues in the models of α-DTX, <i>Eg</i>KU-1 and <i>Eg</i>KU-4. (B) Molecular surface electrostatic representations of the same proteins in the same orientation, highlighting global differences in charge distribution; scale represents charge from positive blue to negative red. (C) Sequence alignment produced with TEXshade [<a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1006169#ppat.1006169.ref082" target="_blank">82</a>] and hand-edited, featuring aromatic, acid and basic residues; those with solvent-accessibilities < 40 Å<sup>2</sup> are grey shaded. Note that structurally equivalent positions in the <i>Eg</i>KUs and α-DTX are shifted two residues in the primary sequence. The P1 site of serine peptidase inhibitors, located at the center of the antipeptidase loop, is indicated with arrowheads in (A) and (C).</p
