Surface model of TEV bound to uncleaved substrate (black), also showing the catalytic triad (red). The substrate binds inside an active site tunnel (left). A cutaway (right) shows the complementary shape of the binding tunnel to the substrate. (<span class="plainlinks"><a href="https://en.wikipedia.org/wiki/Protein_Data_Bank" class="extiw" title="w:Protein Data Bank">PDB</a>: <a rel="nofollow" class="external text" href="http://www.rcsb.org/pdb/explore/explore.do?structureId=1lvb">1lvb</a></span>​)
<a href="//commons.wikimedia.org/wiki/User:Evolution_and_evolvability" title="User:Evolution and evolvability">Thomas Shafee</a>
CC BY 4.0
<cite style="font-style:normal">Thomas, Shafee, (2014). "<a rel="nofollow" class="external text" href="https://www.repository.cam.ac.uk/handle/1810/245207">Evolvability of a viral protease: experimental evolution of catalysis, robustness and specificity</a>". <i>PhD Thesis</i>. University of Cambridge.</cite>