<p>Ribbon diagram of a human <a href="https://en.wikipedia.org/wiki/adenine_phosphoribosyltransferase" class="extiw" title="w:adenine phosphoribosyltransferase">adenine phosphoribosyltransferase</a> (<b>APRTase</b>) <a href="https://en.wikipedia.org/wiki/dimer" class="extiw" title="w:dimer">dimer</a> in complex with <a href="https://en.wikipedia.org/wiki/phosphoribosyl_pyrophosphate" class="extiw" title="w:phosphoribosyl pyrophosphate">phosphoribosyl pyrophosphate</a>, <a href="https://en.wikipedia.org/wiki/adenine" class="extiw" title="w:adenine">adenine</a> and <a href="https://en.wikipedia.org/wiki/ribose_5-phosphate" class="extiw" title="w:ribose 5-phosphate">ribose 5-phosphate</a>. Units colored from <a href="https://en.wikipedia.org/wiki/N-terminal_end" class="extiw" title="w:N-terminal end">N-</a> to <a href="https://en.wikipedia.org/wiki/C-terminal_end" class="extiw" title="w:C-terminal end">C-terminal end</a>; one <a href="https://en.wikipedia.org/wiki/magnesium" class="extiw" title="w:magnesium">magnesium</a> ion visible in green, the other obscured.<br>Created using <a rel="nofollow" class="external text" href="http://www.accelrys.com/products/downloads/ds_visualizer/index.html">Accelrys DS Visualizer Pro 1.6</a> and <a href="https://en.wikipedia.org/wiki/GIMP" class="extiw" title="w:GIMP">GIMP</a>.
</p>
<dl><dt>Legend</dt></dl><div class="legend" style="direction:ltr;line-height:23px;"><div class="legend-content" style="display:inline-block;vertical-align:top;box-sizing:border-box;width:34px;height:23px;overflow:hidden;font-size:15px;border:thin solid #333;background:chartreuse;color:#202122;text-align:center;"> </div> <a href="https://en.wikipedia.org/wiki/Magnesium" class="extiw" title="w:Magnesium">Magnesium</a> ion</div>
<a href="//commons.wikimedia.org/wiki/User:Fvasconcellos" title="User:Fvasconcellos">Fvasconcellos</a> 19:25, 20 May 2007 (UTC)
From <a href="https://en.wikipedia.org/wiki/Protein_Data_Bank" class="extiw" title="w:Protein Data Bank">PDB</a> entry <a rel="nofollow" class="external text" href="http://www.rcsb.org/pdb/cgi/explore.cgi?pdbId=1ZN7">1ZN7</a>.