A random sequential mechanism of aminoglycoside acetylation by Mycobacterium tuberculosis Eis protein.
An important cause of bacterial resistance to aminoglycoside antibiotics is the enzymatic acetylation of their amino groups by acetyltransferases, which abolishes their binding to and inhibition of the bacterial ribosome. Enhanced intracellular survival (Eis) protein from Mycobacterium tuberculosis (Mt) is one of such acetyltransferases, whose upregulation was recently established as a cause of resistance to aminoglycosides in clinical cases of drug-resistant tuberculosis. The mechanism of aminoglycoside acetylation by MtEis is not completely understood. A systematic analysis of steady-state kinetics of acetylation of kanamycin A and neomycin B by Eis as a function of concentrations of these aminoglycosides and the acetyl donor, acetyl coenzyme A, reveals that MtEis employs a random-sequential bisubstrate mechanism of acetylation and yields the values of the kinetic parameters of this mechanism. The implications of these mechanistic properties for the design of inhibitors of Eis and other aminoglycoside acetyltransferases are discussed.
Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, BioPharm Complex, Lexington, Kentucky, United States of America.
Oleg V
OV
Tsodikov
Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, BioPharm Complex, Lexington, Kentucky, United States of America.
Keith D
KD
Green
Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, BioPharm Complex, Lexington, Kentucky, United States of America.
Sylvie
S
Garneau-Tsodikova
D000105:Acetyl Coenzyme A / Q000378:metabolism*; D000107:Acetylation / Q000187:drug effects*; D000123:Acetyltransferases / Q000378:metabolism*; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D000942:Antigens, Bacterial / Q000378:metabolism*; D001426:Bacterial Proteins / Q000378:metabolism*; D001665:Binding Sites; D005601:Framycetin / Q000494:pharmacology*; D007700:Kinetics; D013379:Substrate Specificity
D000900:Anti-Bacterial Agents; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D005601:Framycetin; D000105:Acetyl Coenzyme A; D000123:Acetyltransferases; C430563:Eis protein, Mycobacterium tuberculosis; C019681:aminoglycoside acetyltransferase