Substrate base binding pocket of <i>Z.</i> <i>mobilis</i> Tgt and modelled human Tgt.<b> </b>

<p>A) Detail of <i>Z. mobilis</i> Tgt·preQ₁ complex crystal structure (PDB-code: <b><u>1p0e</u></b>) showing the active site with the bound substrate in stick representation. Carbon atoms of protein residues are coloured in green, those of preQ₁ in orange. B) Homology model of human Tgt created with the <i>Z. mobilis</i> Tgt crystal structure as a template. The close up shows active site residues (carbon atoms in grey) superimposed with preQ₁ (carbon atoms in orange) as present in <b><u>1p0e</u></b>. The coordinates of the homology model are provided within the Supporting Information (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0064240#pone.0064240.s001" target="_blank">Coordinates S1</a>).