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Insight into the AcrAB-TolC Complex Assembly Process Learned from Competition Studies

The RND family efflux pump AcrAB-TolC in E. coli and its homologs in other Gram-negative bacteria are major players in conferring multidrug resistance to the cells. While the structure of the pump complex has been elucidated with ever-increasing resolution through crystallography and Cryo-EM efforts...

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Autores principales: Rajapaksha, Prasangi, Ojo, Isoiza, Yang, Ling, Pandeya, Ankit, Abeywansha, Thilini, Wei, Yinan
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2021
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8300762/
https://www.ncbi.nlm.nih.gov/pubmed/34356751
http://dx.doi.org/10.3390/antibiotics10070830
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author Rajapaksha, Prasangi
Ojo, Isoiza
Yang, Ling
Pandeya, Ankit
Abeywansha, Thilini
Wei, Yinan
author_facet Rajapaksha, Prasangi
Ojo, Isoiza
Yang, Ling
Pandeya, Ankit
Abeywansha, Thilini
Wei, Yinan
author_sort Rajapaksha, Prasangi
collection PubMed
description The RND family efflux pump AcrAB-TolC in E. coli and its homologs in other Gram-negative bacteria are major players in conferring multidrug resistance to the cells. While the structure of the pump complex has been elucidated with ever-increasing resolution through crystallography and Cryo-EM efforts, the dynamic assembly process remains poorly understood. Here, we tested the effect of overexpressing functionally defective pump components in wild type E. coli cells to probe the pump assembly process. Incorporation of a defective component is expected to reduce the efflux efficiency of the complex, leading to the so called “dominant negative” effect. Being one of the most intensively studied bacterial multidrug efflux pumps, many AcrA and AcrB mutations have been reported that disrupt efflux through different mechanisms. We examined five groups of AcrB and AcrA mutants, defective in different aspects of assembly and substrate efflux. We found that none of them demonstrated the expected dominant negative effect, even when expressed at concentrations many folds higher than their genomic counterpart. The assembly of the AcrAB-TolC complex appears to have a proof-read mechanism that effectively eliminated the formation of futile pump complex.
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spelling pubmed-83007622021-07-24 Insight into the AcrAB-TolC Complex Assembly Process Learned from Competition Studies Rajapaksha, Prasangi Ojo, Isoiza Yang, Ling Pandeya, Ankit Abeywansha, Thilini Wei, Yinan Antibiotics (Basel) Article The RND family efflux pump AcrAB-TolC in E. coli and its homologs in other Gram-negative bacteria are major players in conferring multidrug resistance to the cells. While the structure of the pump complex has been elucidated with ever-increasing resolution through crystallography and Cryo-EM efforts, the dynamic assembly process remains poorly understood. Here, we tested the effect of overexpressing functionally defective pump components in wild type E. coli cells to probe the pump assembly process. Incorporation of a defective component is expected to reduce the efflux efficiency of the complex, leading to the so called “dominant negative” effect. Being one of the most intensively studied bacterial multidrug efflux pumps, many AcrA and AcrB mutations have been reported that disrupt efflux through different mechanisms. We examined five groups of AcrB and AcrA mutants, defective in different aspects of assembly and substrate efflux. We found that none of them demonstrated the expected dominant negative effect, even when expressed at concentrations many folds higher than their genomic counterpart. The assembly of the AcrAB-TolC complex appears to have a proof-read mechanism that effectively eliminated the formation of futile pump complex. MDPI 2021-07-08 /pmc/articles/PMC8300762/ /pubmed/34356751 http://dx.doi.org/10.3390/antibiotics10070830 Text en © 2021 by the authors. https://creativecommons.org/licenses/by/4.0/Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Rajapaksha, Prasangi
Ojo, Isoiza
Yang, Ling
Pandeya, Ankit
Abeywansha, Thilini
Wei, Yinan
Insight into the AcrAB-TolC Complex Assembly Process Learned from Competition Studies
title Insight into the AcrAB-TolC Complex Assembly Process Learned from Competition Studies
title_full Insight into the AcrAB-TolC Complex Assembly Process Learned from Competition Studies
title_fullStr Insight into the AcrAB-TolC Complex Assembly Process Learned from Competition Studies
title_full_unstemmed Insight into the AcrAB-TolC Complex Assembly Process Learned from Competition Studies
title_short Insight into the AcrAB-TolC Complex Assembly Process Learned from Competition Studies
title_sort insight into the acrab-tolc complex assembly process learned from competition studies
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8300762/
https://www.ncbi.nlm.nih.gov/pubmed/34356751
http://dx.doi.org/10.3390/antibiotics10070830
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