The Active Site Protonation States of Perdeuterated Toho-1 Beta-Lactamase Determined by Neutron Diffraction Support a Role for Glu166 as the General Base in Acylation.
Tomanicek, S.J., Wang, K.K., Weiss, K.L., Blakeley, M.P., Cooper, J., Chen, Y., Coates, L.(2011) FEBS Lett 585: 364
- PubMed: 21168411 
- DOI: https://doi.org/10.1016/j.febslet.2010.12.017
- Primary Citation of Related Structures:  
2XQZ, 2XR0 - PubMed Abstract: 
Room temperature neutron diffraction data of the fully perdeuterated Toho-1 R274N/R276N double mutant β-lactamase in the apo form were used to visualize deuterium atoms within the active site of the enzyme. This perdeuterated neutron structure of the Toho-1 R274N/R276N reveals the clearest picture yet of the ground-state active site protonation states and the complete hydrogen-bonding network in a β-lactamase enzyme. The ground-state active site protonation states detailed in this neutron diffraction study are consistent with previous high-resolution X-ray studies that support the role of Glu166 as the general base during the acylation reaction in the class A β-lactamase reaction pathway.
Organizational Affiliation: 
Oak Ridge National Laboratory, Neutron Scattering Science Division, Oak Ridge, TN 37831, USA.