4IVK: Crystal Structure Of A Fammily Viii Carboxylesterase In A Complex With Cephalothin

EstU1 is a unique family VIII carboxylesterase that displays hydrolytic activity toward the amide bond of clinically used beta-lactam antibiotics as well as the ester bond of p-nitrophenyl esters. EstU1 assumes a beta-lactamase-like modular architecture and contains the residues Ser100, Lys103, and Tyr218, which correspond to the three catalytic residues (Ser64, Lys67, and Tyr150, respectively) of class C beta-lactamases. The structure of the EstU1/cephalothin complex demonstrates that the active site of EstU1 is not ideally tailored to perform an efficient deacylation reaction during the hydrolysis of beta-lactam antibiotics. This result explains the weak beta-lactamase activity of EstU1 compared with class C beta-lactamases. Finally, structural and sequential comparison of EstU1 with other family VIII carboxylesterases elucidates an operative molecular strategy used by family VIII carboxylesterases to extend their substrate spectrum. Proteins 2013; 81:2045-2051. (c) 2013 Wiley Periodicals, Inc.
PDB ID: 4IVKDownload
MMDB ID: 111080
PDB Deposition Date: 2013/1/23
Updated in MMDB: 2013/10
Experimental Method:
x-ray diffraction
Resolution: 1.8  Å
Source Organism:
Similar Structures:
Biological Unit for 4IVK: monomeric; determined by author
Molecular Components in 4IVK
Label Count Molecule
Protein (1 molecule)
Molecule annotation
Chemicals (5 molecules)
* Click molecule labels to explore molecular sequence information.

Citing MMDB