Three-dimensional structure of the elastase of Pseudomonas aeruginosa at 1.5-A resolution

Pseudomonas aeruginosa elastase (PAE) is a zinc metalloprotease with 301 amino acids. We have crystallized and solved the three-dimensional structure of PAE, using data to 1.5-A resolution, and have refined the native molecular structure to R = 0.188. The overall tertiary structure of the PAE molecule is similar to that of thermolysin, with which it shares 28% amino acid sequence identity. Nearly all of the active site residues that might potentially interact with substrates are identical in the two proteins. However, the active site cleft is significantly more "open" in PAE than in thermolysin.