Cartoon model of superimposed human GUS and bacterial β-galactosidas.

<p>(<b>A</b>). Roll jelly like domain and (<b>B</b>). TIM barrel domains. Human GUS is shown in light red and bacterial β-galactosidase in sky blue. The side chains of active site residues of human and bacterial GUS are shown in ball and stick. Atomic coordinates of bacterial protein were taken from pdb code 1DP0 <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0079687#pone.0079687-Juers1" target="_blank">[52]</a>.