A low-barrier hydrogen bond mediates antibiotic resistance in a noncanonical catalytic triad.Kumar, P., Serpersu, E.H., Cuneo, M.J.
(2018) Sci Adv 4: eaas8667-eaas8667
- PubMed: 29632894
- DOI: 10.1126/sciadv.aas8667
- Primary Citation of Related Structures:
- PubMed Abstract:
One group of enzymes that confer resistance to aminoglycoside antibiotics through covalent modification belongs to the GCN5-related <i>N </i>-acetyltransferase (GNAT) superfamily. We show how a unique GNAT subfamily member uses a previously unidenti ...
One group of enzymes that confer resistance to aminoglycoside antibiotics through covalent modification belongs to the GCN5-related N -acetyltransferase (GNAT) superfamily. We show how a unique GNAT subfamily member uses a previously unidentified noncanonical catalytic triad, consisting of a glutamic acid, a histidine, and the antibiotic substrate itself, which acts as a nucleophile and attacks the acetyl donor molecule. Neutron diffraction studies allow for unambiguous identification of a low-barrier hydrogen bond, predicted in canonical catalytic triads to increase basicity of the histidine. This work highlights the role of this unique catalytic triad in mediating antibiotic resistance while providing new insights into the design of the next generation of aminoglycosides.
Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA.,National Science Foundation, 2415 Eisenhower Avenue, Alexandria, VA 22314, USA.,Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA.,University of Tennessee-Oak Ridge National Laboratory Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, TN 37996, USA.