The crystal structure of glutamyl endopeptidase from Bacillus intermedius reveals a structural link between zymogen activation and charge compensation.
Meijers, R., Blagova, E.V., Levdikov, V.M., Rudenskaya, G.N., Chestukhina, G.G., Akimkina, T.V., Kostrov, S.V., Lamzin, V.S., Kuranova, I.P.(2004) Biochemistry 43: 2784-2791
- PubMed: 15005613 
- DOI: https://doi.org/10.1021/bi035354s
- Primary Citation of Related Structures:  
1P3C, 1P3E - PubMed Abstract: 
Extracellular glutamyl endopeptidase from Bacillus intermedius (BIEP) is a chymotrypsin-like serine protease which cleaves the peptide bond on the carboxyl side of glutamic acid. Its three-dimensional structure was determined for C222(1) and C2 crystal forms of BIEP to 1.5 and 1.75 A resolution, respectively. The topology of BIEP diverges from the most common chymotrypsin architecture, because one of the domains consists of a beta-sandwich consisting of two antiparallel beta-sheets and two helices. In the C2 crystals, a 2-methyl-2,4-pentanediol (MPD) molecule was found in the substrate binding site, mimicking a glutamic acid. This enabled the identification of the residues involved in the substrate recognition. The presence of the MPD molecule causes a change in the active site; the interaction between two catalytic residues (His47 and Ser171) is disrupted. The N-terminal end of the enzyme is involved in the formation of the substrate binding pocket. This indicates a direct relation between zymogen activation and substrate charge compensation.
Organizational Affiliation: 
European Molecular Biology Laboratory, c/o DESY, Notkestrasse 85, D-22603 Hamburg, Germany.