Structural similarity of trypsin and chymotrypsin. An overlay of the structure of chymotrypsin (red) on that of trypsin (blue) is shown. Notice the high degree of similarity. Only α-carbon-atom positions are shown. The mean deviation in position between corresponding α-carbon atoms is 1.7 Å.

[Drawn from 5PTP.pdb and 1GCT.pdb.]