title: The active site protonation states of perdeuterated Toho-1 β-lactamase determined by neutron diffraction support a role for Glu166 as the general base in acylation.
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.
authors.affiliation: Oak Ridge National Laboratory, Neutron Scattering Science Division, Oak Ridge, TN 37831, USA.
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Tomanicek
authors.forename: Kathy K
authors.initials: KK
authors.lastname: Wang
authors.forename: Kevin L
authors.initials: KL
authors.lastname: Weiss
authors.forename: Matthew P
authors.initials: MP
authors.lastname: Blakeley
authors.forename: Jonathan
authors.initials: J
authors.lastname: Cooper
authors.forename: Yu
authors.initials: Y
authors.lastname: Chen
authors.forename: Leighton
authors.initials: L
authors.lastname: Coates
mesh_terms: D000215:Acylation; D020134:Catalytic Domain; D003903:Deuterium; D018698:Glutamic Acid; D006860:Hydrogen Bonding; D050505:Mutant Proteins / Q000737:chemistry; D020125:Mutation, Missense; D033363:Neutron Diffraction / Q000379:methods*; D001618:beta-Lactamases / Q000737:chemistry*
chemical_list: D050505:Mutant Proteins; D018698:Glutamic Acid; D003903:Deuterium; D001618:beta-Lactamases