skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Conformational restriction shapes the inhibition of a multidrug efflux adaptor protein

Journal Article · · Nature Communications

Abstract 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 barrel 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.

Research Organization:
Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
Sponsoring Organization:
USDOE; National Institutes of Health (NIH); National Science Foundation (NSF)
Grant/Contract Number:
AC05-00OR22725; R01-AI052293; ACI-1548562; 1828187
OSTI ID:
1991148
Alternate ID(s):
OSTI ID: 1991730
Journal Information:
Nature Communications, Journal Name: Nature Communications Vol. 14 Journal Issue: 1; ISSN 2041-1723
Publisher:
Nature Publishing GroupCopyright Statement
Country of Publication:
United Kingdom
Language:
English

References (62)

The styrene–maleic acid copolymer: a versatile tool in membrane research journal December 2015
Perturbed structural dynamics underlie inhibition and altered efflux of the multidrug resistance pump AcrB journal November 2020
Practical applications and feasibility of efflux pump inhibitors in the clinic—A vision for applied use journal March 2006
Bifurcation kinetics of drug uptake by Gram-negative bacteria journal September 2017
Breaking the permeability barrier of Escherichia coli by controlled hyperporination of the outer membrane. journal October 2016
Structure of the AcrAB–TolC multidrug efflux pump journal April 2014
Scalable molecular dynamics with NAMD journal January 2005
Identification and Structure–Activity Relationships of Novel Compounds that Potentiate the Activities of Antibiotics in Escherichia coli journal July 2017
pH-induced Conformational Changes of AcrA, the Membrane Fusion Protein of Escherichia coli Multidrug Efflux System journal December 2003
Kinetic control of TolC recruitment by multidrug efflux complexes journal September 2009
Scalable molecular dynamics on CPU and GPU architectures with NAMD journal July 2020
The gram-negative bacterial periplasm: Size matters journal January 2018
AcrB-AcrA Fusion Proteins That Act as Multidrug Efflux Transporters journal January 2016
Interdomain Flexibility and pH-Induced Conformational Changes of AcrA Revealed by Molecular Dynamics Simulations journal March 2012
AlphaFold Protein Structure Database: massively expanding the structural coverage of protein-sequence space with high-accuracy models journal November 2021
Highly accurate protein structure prediction with AlphaFold journal July 2021
The C-Terminal Domain of AcrA Is Essential for the Assembly and Function of the Multidrug Efflux Pump AcrAB-TolC journal May 2009
Multidrug Resistance in Bacteria journal June 2009
Differential hydrogen/deuterium exchange mass spectrometry analysis of protein–ligand interactions journal February 2011
Structure of the periplasmic component of a bacterial drug efflux pump journal June 2004
Inhibition of DNA gyrase and DNA topoisomerase IV of Staphylococcus aureus and Escherichia coli by aminocoumarin antibiotics journal June 2011
Considerations in the Analysis of Hydrogen Exchange Mass Spectrometry Data book September 2019
UCSF Chimera?A visualization system for exploratory research and analysis journal January 2004
Interchangeability of periplasmic adaptor proteins AcrA and AcrE in forming functional efflux pumps with AcrD in Salmonella enterica serovar Typhimurium journal July 2021
HD-eXplosion: visualization of hydrogen–deuterium exchange data as chiclet and volcano plots with statistical filtering journal October 2020
Bacterial multidrug efflux pumps: Mechanisms, physiology and pharmacological exploitations journal October 2014
Ensemble Methods Enable a New Definition for the Solution to Gas-Phase Transfer of Intrinsically Disordered Proteins journal October 2015
Federal Funding for the Study of Antimicrobial Resistance in Nosocomial Pathogens: No ESKAPE journal April 2008
Antibacterial resistance worldwide: causes, challenges and responses journal November 2004
Efflux pump inhibitors of clinically relevant multidrug resistant bacteria journal April 2019
A role for the periplasmic adaptor protein AcrA in vetting substrate access to the RND efflux transporter AcrB journal March 2022
Drug transport mechanism of the AcrB efflux pump journal May 2009
Conformational Dynamics of AcrA Govern Multidrug Efflux Pump Assembly journal September 2019
SMA-PAGE: A new method to examine complexes of membrane proteins using SMALP nano-encapsulation and native gel electrophoresis journal August 2019
Conformational dynamics of human FXR-LBD ligand interactions studied by hydrogen/deuterium exchange mass spectrometry: Insights into the antagonism of the hypolipidemic agent Z-guggulsterone journal September 2014
Complementary packing of α-helices in proteins journal December 1999
Recommendations for performing, interpreting and reporting hydrogen deuterium exchange mass spectrometry (HDX-MS) experiments journal June 2019
Particle mesh Ewald: An N ⋅log( N ) method for Ewald sums in large systems journal June 1993
Identification of Binding Sites for Efflux Pump Inhibitors of the AcrAB-TolC Component AcrA journal February 2019
Sequential Mechanism of Assembly of Multidrug Efflux Pump AcrAB-TolC journal April 2011
Identification of binding residues between periplasmic adapter protein (PAP) and RND efflux pumps explains PAP-pump promiscuity and roles in antimicrobial resistance journal December 2019
Orbitrap Mass Spectrometry journal May 2013
AcrA is a highly asymmetric protein capable of spanning the periplasm 1 1Edited by I. B. Holland journal January 1999
Conformational Characterization and Classification of Intrinsically Disordered Proteins by Native Mass Spectrometry and Charge‐State Distribution Analysis journal November 2018
Optimized Workflow for Selecting Peptides for HDX-MS Data Analyses journal August 2018
Conformational Flexibility in the Multidrug Efflux System Protein AcrA journal March 2006
The Utility of Hydrogen/Deuterium Exchange Mass Spectrometry in Biopharmaceutical Comparability Studies journal June 2011
In situ structure of the AcrAB-TolC efflux pump at subnanometer resolution journal January 2022
AcrA, AcrB, and TolC of Escherichia coli Form a Stable Intermembrane Multidrug Efflux Complex journal July 2004
pH of the Cytoplasm and Periplasm of Escherichia coli: Rapid Measurement by Green Fluorescent Protein Fluorimetry journal June 2007
Direct Inhibition of MmpL3 by Novel Antitubercular Compounds journal March 2019
Evidence for Micellar Structure in the Gas Phase journal July 2007
Global burden of bacterial antimicrobial resistance in 2019: a systematic analysis journal February 2022
Dead cells release a ‘necrosignal’ that activates antibiotic survival pathways in bacterial swarms journal August 2020
Conformational dynamics of free and membrane-bound human Hsp70 in model cytosolic and endo-lysosomal environments journal December 2021
Reviving Antibiotics: Efflux Pump Inhibitors That Interact with AcrA, a Membrane Fusion Protein of the AcrAB-TolC Multidrug Efflux Pump journal November 2016
Using hydrogen deuterium exchange mass spectrometry to engineer optimized constructs for crystallization of protein complexes: Case study of PI4KIIIβ with Rab11 journal February 2016
Efflux-linked accelerated evolution of antibiotic resistance at a population edge journal November 2022
A Mass-Spectrometry-Based Framework To Define the Extent of Disorder in Proteins journal October 2014
Simple and Fast Maximally Deuterated Control (maxD) Preparation for Hydrogen–Deuterium Exchange Mass Spectrometry Experiments journal July 2022
Mass spectrometry guided structural biology journal October 2016
Bayesian Deconvolution of Mass and Ion Mobility Spectra: From Binary Interactions to Polydisperse Ensembles journal April 2015

Similar Records

Discovery of multidrug efflux pump inhibitors with a novel chemical scaffold
Journal Article · Tue Feb 04 00:00:00 EST 2020 · Biochimica et Biophysica Acta - General Subjects · OSTI ID:1991148

Mechanistic Duality of Bacterial Efflux Substrates and Inhibitors: Example of Simple Substituted Cinnamoyl and Naphthyl Amides
Journal Article · Wed Aug 11 00:00:00 EDT 2021 · ACS Infectious Diseases · OSTI ID:1991148

Conformational Dynamics of AcrA Govern Multidrug Efflux Pump Assembly
Journal Article · Fri Sep 13 00:00:00 EDT 2019 · ACS Infectious Diseases · OSTI ID:1991148