RT Journal Article
SR Electronic
T1 Conformational restriction shapes inhibition of a multidrug efflux adaptor protein
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2022.12.09.519754
DO 10.1101/2022.12.09.519754
A1 Benjamin Russell Lewis
A1 Muhammad R. Uddin
A1 Mohammad Moniruzzaman
A1 Katie M. Kuo
A1 Anna J. Higgins
A1 Laila M. N. Shah
A1 Frank Sobott
A1 Jerry M. Parks
A1 Dietmar Hammerschmid
A1 James C. Gumbart
A1 Helen I. Zgurskaya
A1 Eamonn Reading
YR 2022
UL http://biorxiv.org/content/early/2022/12/09/2022.12.09.519754.abstract
AB Membrane efflux pumps play a major role in bacterial multidrug resistance. The tripartite multidrug efflux pump system from Escherichia coli, AcrAB-TolC, is a target for inhibition to lessen resistance development and restore antibiotic efficacy, with homologs in other ESKAPE pathogens. Here, we rationalize a mechanism of inhibition against the periplasmic adaptor protein, AcrA, using a combination of hydrogen/deuterium exchange mass spectrometry, cellular efflux assays, and molecular dynamics simulations. We define the structural dynamics of AcrA and find that an inhibitor can inflict long-range stabilisation across all four of its domains, whereas an interacting efflux substrate has minimal effect. Our results support a model where an inhibitor forms a molecular wedge within a cleft between the lipoyl and αβ domains of AcrA, diminishing its conformational transmission of drug-evoked signals from AcrB to TolC. This work provides molecular insights into multidrug adaptor protein function which could be valuable for developing antimicrobial therapeutics.Competing Interest StatementThe authors have declared no competing interest.