Subtilisin

"Subtilisin is a non-specific protease (a protein-digesting enzyme) initially obtained from Bacillus subtilis. Subtilisins belong to subtilases, a group of serine proteases that - like all serine proteases - initiate the nucleophilic attack on the peptide (amide) bond through a serine residue at the active site."
--https://en.wikipedia.org/wiki/Subtilisin

Of note is that the catalytic mechanism is identical to that of Trypsin.

The STL file contains a representation of the protein in cartoon form with catalytic residues represented as spheres. Model based on the Protein Data Bank entry 1CSE:
--http://www.pdb.org/pdb/explore/explore.do?pdbId=1cse

Model created using VMD:
http://www.ks.uiuc.edu/Research/vmd/