Comparison of free bases bound to the BsPNP233 active site.

<p>A. Structural comparison of a representative BsPNP233-Ade complex (<i>purple</i> carbon atoms) with the BsPNP233-Hyp complex (<i>grey</i> carbon atoms). B. The structure of the four BsPNP233-Ade complexes solved independently are superimposed. The sulfate-free Ade-complexes are colored in <i>purple</i> (chain A) and <i>pink</i> (chain B) whereas the two independent complexes solved with sulfate bound (dataset I) are colored in <i>orange</i> (chain A) and <i>blue</i> (chain B). C. The structure of the Ade-complex where Ade presents an alternative conformation (carbon atoms in <i>orange</i>) is superimposed in the structure of Hyp-complex (carbon atoms in <i>grey</i>). The surface of the glycerol molecule present at the Hyp-complex is shown to evidence the influence of this molecule in the position and orientation of Hyp in the active site. The hydrogen bonds are shown as <i>dashed lines.</i>