Structural model of fH-fHbp complex.

<p>fH fragment is shown in gray. The amino-terminal domain of fHbp is shown in light blue, while the carboxy-terminal domain is shown in light green. <b>Panel A.</b> Alanine substitutions for arginine at residue 204 (R204A) or for lysine at position 143 (K143A) decreased or eliminated JAR 1 binding. His substitution for Arg at position 204 (R204H) did not affect JAR 1 binding (See <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0034272#pone-0034272-g005" target="_blank">Figure 5</a>). <b>Panel B.</b> Residues shown previously by NMR to be part of the mAb502 binding site <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0034272#pone.0034272-Scarselli1" target="_blank">[29]</a>. In addition, we found that alanine or histidine substitutions for arginine at residue 204 (R204A or R204H) eliminated binding of mAb502, and an alanine substitution for aspartic acid at residue 142 (D142A) decreased binding (See <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0034272#pone-0034272-g003" target="_blank">Figure 3</a>). The figure was constructed with PyMol (<a href="http://www.pymol.org" target="_blank">http://www.pymol.org</a>).