3JTR: Mutations in Cephalosporin Acylase Affecting Stability and Autoproteolysis

Cephalosporin acylase (CA), a member of the N-terminal nucleophile hydrolase family, is activated through two steps of intramolecular autoproteolysis, the first mediated by a serine residue, and the second by a glutamate, which releases the pro-segment and produces an active enzyme. In this study, we have determined the crystal structures of mutants which could affect primary or secondary auto-cleavage and of sequential intermediates of a slow-processing mutant at 2.0-2.5A resolutions. The pro-segments of the mutants undergo dynamic conformational changes during activation and adopt surprisingly different loop conformations from one another. However, the autoproteolytic site was found to form a catalytically competent conformation with a solvent water molecule, which was essentially conserved in the CA mutants.
PDB ID: 3JTRDownload
MMDB ID: 79615
PDB Deposition Date: 2009/9/14
Updated in MMDB: 2017/11
Experimental Method:
x-ray diffraction
Resolution: 2.5  Å
Source Organism:
Similar Structures:
Biological Unit for 3JTR: dimeric; determined by author and by software (PISA)
Molecular Components in 3JTR
Label Count Molecule
Proteins (2 molecules)
Glutaryl 7-aminocephalosporanic Acid Acylase
Molecule annotation
Glutaryl 7-aminocephalosporanic Acid Acylase
Molecule annotation
Chemical (1 molecule)
* Click molecule labels to explore molecular sequence information.

Citing MMDB