Fig 7. Overall cartoon representation of the active site in BtDPP III structure in the closed form.
2mFo-DFc electron density at 1 σ (blue) and mFo-DFc electron density at 3 σ (green) correspond to the substrate-binding position. The upper structural domain is shown in blue, the lower one in magenta, and the zinc atom as a grey sphere. The amino acids binding the zinc ion, Tris, and Tyr-Phe-NHOH are shown in stick representation. (A) Electron density map in the active site; (B) electron density with Tyr-Phe-NHOH included in the refinement; (C) electron density with Tris included in the refinement. The figure was prepared using the PyMol program (http://www.pymol.org/).