Biochemical and structural analysis of an Eis family aminoglycoside acetyltransferase from bacillus anthracis.
Proteins from the enhanced intracellular survival (Eis) family are versatile acetyltransferases that acetylate amines at multiple positions of several aminoglycosides (AGs). Their upregulation confers drug resistance. Homologues of Eis are present in diverse bacteria, including many pathogens. Eis from Mycobacterium tuberculosis (Eis_Mtb) has been well characterized. In this study, we explored the AG specificity and catalytic efficiency of the Eis family protein from Bacillus anthracis (Eis_Ban). Kinetic analysis of specificity and catalytic efficiency of acetylation of six AGs indicates that Eis_Ban displays significant differences from Eis_Mtb in both substrate binding and catalytic efficiency. The number of acetylated amines was also different for several AGs, indicating a distinct regiospecificity of Eis_Ban. Furthermore, most recently identified inhibitors of Eis_Mtb did not inhibit Eis_Ban, underscoring the differences between these two enzymes. To explain these differences, we determined an Eis_Ban crystal structure. The comparison of the crystal structures of Eis_Ban and Eis_Mtb demonstrates that critical residues lining their respective substrate binding pockets differ substantially, explaining their distinct specificities. Our results suggest that acetyltransferases of the Eis family evolved divergently to garner distinct specificities while conserving catalytic efficiency, possibly to counter distinct chemical challenges. The unique specificity features of these enzymes can be utilized as tools for developing AGs with novel modifications and help guide specific AG treatments to avoid Eis-mediated resistance.
⊥Department of Pharmaceutical Sciences, University of Kentucky, Lexington, Kentucky 40536-0596, United States.
Keith D
KD
Green
Tapan
T
Biswas
∇Structural Biology Center, Biosciences, Argonne National Laboratory, Argonne, Illinois 60439, United States.
Changsoo
C
Chang
∇Structural Biology Center, Biosciences, Argonne National Laboratory, Argonne, Illinois 60439, United States.
Ruiying
R
Wu
Wenjing
W
Chen
Brian K
BK
Janes
Dominika
D
Chalupska
Piotr
P
Gornicki
Philip C
PC
Hanna
⊥Department of Pharmaceutical Sciences, University of Kentucky, Lexington, Kentucky 40536-0596, United States.
Oleg V
OV
Tsodikov
∇Structural Biology Center, Biosciences, Argonne National Laboratory, Argonne, Illinois 60439, United States.
Andrzej
A
Joachimiak
⊥Department of Pharmaceutical Sciences, University of Kentucky, Lexington, Kentucky 40536-0596, United States.
Sylvie
S
Garneau-Tsodikova
D000107:Acetylation; D000123:Acetyltransferases / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000378:metabolism; D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001408:Bacillus anthracis / Q000187:drug effects / Q000201:enzymology*; D001426:Bacterial Proteins / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000378:metabolism; D020134:Catalytic Domain; D018360:Crystallography, X-Ray; D024881:Drug Resistance, Bacterial; D020128:Inhibitory Concentration 50; D007700:Kinetics; D008826:Microbial Sensitivity Tests; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011499:Protein Processing, Post-Translational; D017433:Protein Structure, Secondary
D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D000123:Acetyltransferases; C019681:aminoglycoside acetyltransferase