Dihydrostreptomycin Directly Binds to, Modulates, and Passes through the MscL Channel Pore.
The primary mechanism of action of the antibiotic dihydrostreptomycin is binding to and modifying the function of the bacterial ribosome, thus leading to decreased and aberrant translation of proteins; however, the routes by which it enters the bacterial cell are largely unknown. The mechanosensitive channel of large conductance, MscL, is found in the vast majority of bacterial species, where it serves as an emergency release valve rescuing the cell from sudden decreases in external osmolarity. While it is known that MscL expression increases the potency of dihydrostreptomycin, it has remained unclear if this effect is due to a direct interaction. Here, we use a combination of genetic screening, MD simulations, and biochemical and mutational approaches to determine if dihydrostreptomycin directly interacts with MscL. Our data strongly suggest that dihydrostreptomycin binds to a specific site on MscL and modifies its conformation, thus allowing the passage of K+ and glutamate out of, and dihydrostreptomycin into, the cell.
Department of Physiology, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America.
Robin
R
Wray
Department of Physiology, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America.
Irene
I
Iscla
School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
Ya
Y
Gao
School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.|School of Traditional Chinese Materia Medica, Shenyang Pharmaceutical University, Shenyang, China.
Hua
H
Li
Green Center for Systems Biology and Biophysics, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America.
Junmei
J
Wang
Department of Physiology, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America.
Paul
P
Blount
D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D001665:Binding Sites / Q000235:genetics; D002462:Cell Membrane / Q000378:metabolism; D003545:Cysteine / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D004096:Dihydrostreptomycin Sulfate / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D004926:Escherichia coli / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D018698:Glutamic Acid / Q000378:metabolism; D015640:Ion Channel Gating; D007473:Ion Channels / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008465:Mechanoreceptors / Q000737:chemistry / Q000378:metabolism; D062105:Molecular Docking Simulation; D056004:Molecular Dynamics Simulation; D009154:Mutation; D011188:Potassium / Q000378:metabolism; D011485:Protein Binding; D011487:Protein Conformation
D000900:Anti-Bacterial Agents; D029968:Escherichia coli Proteins; D007473:Ion Channels; C086596:MscL protein, E coli; D018698:Glutamic Acid; D003545:Cysteine; D011188:Potassium; D004096:Dihydrostreptomycin Sulfate