Adaptability of residues to the bound inhibitors at the active site. In this stereo view, all eight structures, each with an inhibitor (1–8) bound, were superimposed. The inhibitors are shown as thick sticks, and the nearby protein residues are shown as thin sticks. The two Mn(II) ions are shown as spheres and labelled as Mn1 and Mn2. The YHGY loop and residues Y62, H63, Y65 and W221, as well as Mn(II) ions, of each structure are coloured the same as the corresponding inhibitor: 1, yellow; 2, green; 3, cyan; 4, black; 5, magenta; 6, blue; 7, grey; and 8, red.