Research

The N-acetylglucosaminidase NagZ of Pseudomonas aeruginosa catalyzes the first cytoplasmic step in recycling of muropeptides, cell-wall-derived natural products.

This reaction regulates gene expression for the β-lactam resistance enzyme, β-lactamase. The structural and functional aspects of catalysis by NagZ were investigated by a total of seven X-ray structures, three computational models based on the X-ray structures, molecular-dynamics simulations and mutagenesis. The structural insights came from the unbound state and complexes of NagZ with the substrate, products and a mimetic of the transient oxocarbenium species. The catalytic mechanism involves a histidine as an acid/base catalyst, which is unique in glycosidases and is inhibited by zinc ion. This analysis provides a seamless continuum for the catalytic cycle, incorporating the large motions by loops that surround the active site. This is part of a collaborative effort between the IQFR and the Univ. of Notre Dame (Indiana, USA).

Acebrón, I.; Mahasenan, K.; De Benedetti, S.; Lee, M.; Artola-Recolons, C.; Hesek, D.; Wang, H.; Hermoso*, J.A.; Mobashery*, S. “Catalytic Cycle of the N-Acetylglucosaminidase NagZ from Pseudomonas aeruginosa”. J. Am. Chem. Soc. (2017).
DOI:10.1021/jacs.7b01626