Structure and Mechanism of a Bacterial B-Glucosaminidase Having O-Glcnacase Activity
Dennis, R.J., Taylor, E.J., Macauley, M.S., Stubbs, K.A., Turkenburg, J.P., Hart, S.J., Black, G.N., Vocadlo, D.J., Davies, G.J.(2006) Nat Struct Mol Biol 13: 365
- PubMed: 16565725 
- DOI: https://doi.org/10.1038/nsmb1079
- Primary Citation of Related Structures:  
2CHN, 2CHO - PubMed Abstract: 
O-GlcNAc is an abundant post-translational modification of serine and threonine residues of nucleocytoplasmic proteins. This modification, found only within higher eukaryotes, is a dynamic modification that is often reciprocal to phosphorylation. In a manner analogous to phosphatases, a glycoside hydrolase termed O-GlcNAcase cleaves O-GlcNAc from modified proteins. Enzymes with high sequence similarity to human O-GlcNAcase are also found in human pathogens and symbionts. We report the three-dimensional structure of O-GlcNAcase from the human gut symbiont Bacteroides thetaiotaomicron both in its native form and in complex with a mimic of the reaction intermediate. Mutagenesis and kinetics studies show that the bacterial enzyme, very similarly to its human counterpart, operates via an unusual 'substrate-assisted' catalytic mechanism, which will inform the rational design of enzyme inhibitors.
Organizational Affiliation: 
York Structural Biology Laboratory, Department of Chemistry, University of York, York Y010 5YW, UK.