Abstract
The activity of class D β-lactamases is dependent on Lys70 carboxylation in the active site. Structural, kinetic and affinity studies show that this post-translational modification can be affected by the presence of a poor substrate such as moxalactam but also by the V117T substitution. Val117 is a strictly conserved hydrophobic residue located in the active site. In addition, inhibition of class D β-lactamases by chloride ions is due to a competition between the side chain carboxylate of the modified Lys70 and chloride ions. Determination of the individual kinetic constants shows that the deacylation of the acyl-enzyme is the rate-limiting step for the wild-type OXA-10 β-lactamase.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Acylation
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Amino Acid Sequence
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Amino Acid Substitution
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Anti-Bacterial Agents / metabolism
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Bacterial Proteins / chemistry*
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Bacterial Proteins / genetics
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Bacterial Proteins / isolation & purification
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Bacterial Proteins / metabolism*
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Catalytic Domain*
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Chlorides / chemistry
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Conserved Sequence
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Crystallography, X-Ray
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Enzyme Inhibitors / chemistry
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Hydrophobic and Hydrophilic Interactions
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Kinetics
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Lysine / metabolism*
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Moxalactam / metabolism
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Mutant Proteins / antagonists & inhibitors
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Mutant Proteins / chemistry
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Mutant Proteins / isolation & purification
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Mutant Proteins / metabolism
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Osmolar Concentration
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Protein Binding
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Protein Conformation
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Protein Processing, Post-Translational*
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Pseudomonas aeruginosa / enzymology
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Recombinant Proteins / antagonists & inhibitors
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Recombinant Proteins / chemistry
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Recombinant Proteins / isolation & purification
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Recombinant Proteins / metabolism
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beta-Lactamases / chemistry*
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beta-Lactamases / genetics
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beta-Lactamases / isolation & purification
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beta-Lactamases / metabolism*
Substances
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Anti-Bacterial Agents
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Bacterial Proteins
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Chlorides
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Enzyme Inhibitors
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Mutant Proteins
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Recombinant Proteins
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beta-lactamase OXA-10
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beta-Lactamases
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Lysine
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Moxalactam
Associated data
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PDB/1K6R
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PDB/2WGV
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PDB/2WGW
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PDB/2WKH