51
|
Chen X, Chen H, Zhang H, Peng Y, Deng F, Gao J, Chai C, Tang S, Zuo X, Lu J, Du H. Characterization of synergistic antibacterial effect of silver nanoparticles and ebselen. ARTIFICIAL CELLS NANOMEDICINE AND BIOTECHNOLOGY 2019; 47:3338-3349. [PMID: 31387398 DOI: 10.1080/21691401.2019.1648278] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The emerging and spreading of multi-drug resistant (MDR) bacteria have been becoming one of the most severe threats to human health. Enhancing oxidative stress as mimicking immune system was considered as a potential strategy to fight against infection of MDR bacteria. In this study, we investigated the antibacterial efficiency of such a strategy which combines silver nanoparticles (AgNPs) with ebselen. The results showed that AgNPs and ebselen combination had significant synergistic killing effects both on Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) in vitro, including model strains of China Veterinary Culture Collection and MDR clinical isolates, which is similar as the combination of silver ion and ebselen. AgNPs exhibited to be a strong inhibitor of bacterial thioredoxin reductase, same as a free silver ion. Ebselen mitigated the cytotoxicity of AgNPs to HeLa cells. However, in a bacteria-cell coexistence condition, the synergistic bactericidal effect was only observed on S. aureus (p<.05), while the temporary synergistic inhibitory effect on E. coli within 4 hours treatment (p<.01). In mice infection model, a combination of AgNPs and ebselen did not increase protection against the challenge of clinical E. coli CQ10 strain. Our data demonstrated that AgNPs and ebselen combination may be a promising strategy to fight against the increasingly MDR bacteria targeting bacterial thiol redox system.
Collapse
Affiliation(s)
- Xueqing Chen
- a College of Biotechnology, Southwest University , Chongqing , China
| | - Heming Chen
- a College of Biotechnology, Southwest University , Chongqing , China
| | - Hongying Zhang
- a College of Biotechnology, Southwest University , Chongqing , China
| | - Yanjuan Peng
- b Department of Production and Management, Tibet Autonomous Region Veterinary Biologics Factory , Lasa , Tibet , China
| | - Fuchang Deng
- a College of Biotechnology, Southwest University , Chongqing , China
| | - Jiye Gao
- c College of Animal Science, Southwest University , Chongqing , China
| | - Chunli Chai
- a College of Biotechnology, Southwest University , Chongqing , China
| | - Song Tang
- d Chinese Center for Disease Control and Prevention, National Institute of Environmental Health , Beijing , China
| | - Xin Zuo
- e Ministry of Education, College of Pharmaceutical Sciences, Key Laboratory of Luminescent and Real-Time Analytical Chemistry, Southwest University , Chongqing , China
| | - Jun Lu
- e Ministry of Education, College of Pharmaceutical Sciences, Key Laboratory of Luminescent and Real-Time Analytical Chemistry, Southwest University , Chongqing , China
| | - Huamao Du
- a College of Biotechnology, Southwest University , Chongqing , China
| |
Collapse
|
52
|
Tam HK, Malviya VN, Foong WE, Herrmann A, Malloci G, Ruggerone P, Vargiu AV, Pos KM. Binding and Transport of Carboxylated Drugs by the Multidrug Transporter AcrB. J Mol Biol 2019; 432:861-877. [PMID: 31881208 DOI: 10.1016/j.jmb.2019.12.025] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Revised: 12/11/2019] [Accepted: 12/12/2019] [Indexed: 12/13/2022]
Abstract
AcrAB(Z)-TolC is the main drug efflux transporter complex in Escherichia coli. The extrusion of various toxic compounds depends on several drug binding sites within the trimeric AcrB transporter. Membrane-localized carboxylated substrates, such as fusidic acid and hydrophobic β-lactams, access the pump via a groove between the transmembrane helices TM1 and TM2. In this article, the transport route from the initial TM1/TM2 groove binding site toward the deep binding pocket located in the periplasmic part has been addressed via molecular modeling studies followed by functional and structural characterization of several AcrB variants. We propose that membrane-embedded drugs bind initially to the TM1/TM2 groove, are oriented by the AcrB PN2 subdomain, and are subsequently transported via a PN2/PC1 interface pathway directly toward the deep binding pocket. Our work emphasizes the exploitation of multiple transport pathways by AcrB tuned to substrate physicochemical properties related to the polyspecificity of the pump.
Collapse
Affiliation(s)
- Heng-Keat Tam
- Institute of Biochemistry, Goethe University Frankfurt, Max-von-Laue-Str. 9, D-60438 Frankfurt Am Main, Germany
| | - Viveka N Malviya
- Institute of Biochemistry, Goethe University Frankfurt, Max-von-Laue-Str. 9, D-60438 Frankfurt Am Main, Germany
| | - Wuen-Ee Foong
- Institute of Biochemistry, Goethe University Frankfurt, Max-von-Laue-Str. 9, D-60438 Frankfurt Am Main, Germany
| | - Andrea Herrmann
- Institute of Biochemistry, Goethe University Frankfurt, Max-von-Laue-Str. 9, D-60438 Frankfurt Am Main, Germany
| | - Giuliano Malloci
- Department of Physics, University of Cagliari, S.P. 8 Km 0.700, 09042 Monserrato (CA), Italy
| | - Paolo Ruggerone
- Department of Physics, University of Cagliari, S.P. 8 Km 0.700, 09042 Monserrato (CA), Italy
| | - Attilio V Vargiu
- Department of Physics, University of Cagliari, S.P. 8 Km 0.700, 09042 Monserrato (CA), Italy.
| | - Klaas M Pos
- Institute of Biochemistry, Goethe University Frankfurt, Max-von-Laue-Str. 9, D-60438 Frankfurt Am Main, Germany.
| |
Collapse
|
53
|
Kusakizako T, Miyauchi H, Ishitani R, Nureki O. Structural biology of the multidrug and toxic compound extrusion superfamily transporters. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2019; 1862:183154. [PMID: 31866287 DOI: 10.1016/j.bbamem.2019.183154] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 12/05/2019] [Accepted: 12/08/2019] [Indexed: 12/27/2022]
Abstract
Xenobiotic and metabolite extrusion is an important process for the proper functions of cells and their compartments, including acidic organelles. MATE (multidrug and toxic compound extrusion) is a large family of secondary active transporters involved in the transport of various compounds across cellular and organellar membranes, and is present in the three domains of life. The major substrates of the bacterial MATE transporters are cationic compounds, including clinically important antibiotics, and thereby MATE transporters confer multi-drug resistance to pathogenic bacteria. The plant MATE transporters are important for the accumulation of various metabolites in organelles, including vacuoles. The human MATE transporters are expressed in the brush-border membrane of the kidney, and are involved in the clearance of cationic drugs from the body. During the past decade, progress in structural biology has clarified the transport mechanism of these MATE transporters in atomic detail. The present review summarizes the reported structures of MATE family transporters, along with their structure-guided functional analyses. This integrated view of the structures of MATE transporters provides novel insights into their transport mechanism.
Collapse
Affiliation(s)
- Tsukasa Kusakizako
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Hirotake Miyauchi
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Ryuichiro Ishitani
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
| | - Osamu Nureki
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
| |
Collapse
|
54
|
Krah A, Huber RG, Zachariae U, Bond PJ. On the ion coupling mechanism of the MATE transporter ClbM. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2019; 1862:183137. [PMID: 31786188 DOI: 10.1016/j.bbamem.2019.183137] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 10/27/2019] [Accepted: 11/26/2019] [Indexed: 01/02/2023]
Abstract
Bacteria use a number of mechanisms to defend themselves from antimicrobial drugs. One important defense strategy is the ability to export drugs by multidrug transporters. One class of multidrug transporter, the so-called multidrug and toxic compound extrusion (MATE) transporters, extrude a variety of antibiotic compounds from the bacterial cytoplasm. These MATE transporters are driven by a Na+, H+, or combined Na+/H+ gradient, and act as antiporters to drive a conformational change in the transporter from the outward to the inward-facing conformation. In the inward-facing conformation, a chemical compound (drug) binds to the protein, resulting in a switch to the opposite conformation, thereby extruding the drug. Using molecular dynamics simulations, we now report the structural basis for Na+ and H+ binding in the dual ion coupled MATE transporter ClbM from Escherichia coli, which is connected to colibactin-induced genotoxicity, yielding novel insights into the ion/drug translocation mechanism of this bacterial transporter.
Collapse
Affiliation(s)
- Alexander Krah
- Korea Institute for Advanced Study, School of Computational Sciences, 85 Hoegiro, Dongdaemun-gu, Seoul 02455, Republic of Korea; Computational Biology, School of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, UK; Physics, School of Science and Engineering, University of Dundee, Nethergate, Dundee DD1 4NH, UK; Bioinformatics Institute, Agency for Science, Technology and Research (A*STAR), 30 Biopolis Str., #07-01 Matrix, Singapore 138671, Singapore.
| | - Roland G Huber
- Bioinformatics Institute, Agency for Science, Technology and Research (A*STAR), 30 Biopolis Str., #07-01 Matrix, Singapore 138671, Singapore
| | - Ulrich Zachariae
- Computational Biology, School of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, UK; Physics, School of Science and Engineering, University of Dundee, Nethergate, Dundee DD1 4NH, UK
| | - Peter J Bond
- Bioinformatics Institute, Agency for Science, Technology and Research (A*STAR), 30 Biopolis Str., #07-01 Matrix, Singapore 138671, Singapore; National University of Singapore, Department of Biological Sciences, 14 Science Drive 4, Singapore 117543, Singapore
| |
Collapse
|
55
|
Hassan YI, He JW, Lepp D, Zhou T. Understanding the Bacterial Response to Mycotoxins: The Transcriptomic Analysis of Deoxynivalenol-Induced Changes in Devosia mutans 17-2-E-8. Front Pharmacol 2019; 10:1098. [PMID: 31798443 PMCID: PMC6868067 DOI: 10.3389/fphar.2019.01098] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Accepted: 08/26/2019] [Indexed: 12/17/2022] Open
Abstract
Deoxynivalenol (DON) is a major fusarium toxin widely detected in cereal grains. The inadvertent exposure to this fungal secondary-metabolite gives rise to a myriad of adverse health effects including appetite loss, emesis, and suppression of the immune system. While most of the attention this mycotoxin has gained in the past four decades was related to its eukaryotic toxicity (monogastric animals and plants more precisely), recent studies have begun to reveal its negative influence on prokaryotes. Recently presented evidence indicates that DON can negatively affect many bacterial species, raising the possibility of DON-induced imbalances within the microbiota of the human and animal gut, in addition to other environmental niches. This in turn has led to a greater interest in understanding bacterial responses toward DON, and the involved mechanism(s) and metabolic pathways, in order to build a more comprehensive picture of DON-induced changes in both prokaryotes and eukaryotes alike. This study reveals the transcriptomic profiling of Devosia mutans strain 17-2-E-8 after the inclusion of DON within its growth medium. The results highlight three adaptive mechanisms involved in the response of D. mutans 17-2-E-8 to this mycotoxin, which include: (a) activation of adenosine 5’-triphosphate-binding cassette transporters; (b) engagement of a toxin-specific pyrroloquinoline quinone-dependent detoxification pathway; and finally (c) the upregulation of auxiliary coping proteins such as porins, glutathione S-transferases, and phosphotransferases. Some of the identified mechanisms are universal in nature and are shared with other bacterial genera and species.
Collapse
Affiliation(s)
- Yousef I Hassan
- Guelph Research and Development Centre, Agriculture and Agri-Food Canada, Guelph, ON, Canada
| | - Jian Wei He
- Guelph Research and Development Centre, Agriculture and Agri-Food Canada, Guelph, ON, Canada
| | - Dion Lepp
- Guelph Research and Development Centre, Agriculture and Agri-Food Canada, Guelph, ON, Canada
| | - Ting Zhou
- Guelph Research and Development Centre, Agriculture and Agri-Food Canada, Guelph, ON, Canada
| |
Collapse
|
56
|
Epidemiology of efflux pumps genes mediating resistance among Staphylococcus aureus; A systematic review. Microb Pathog 2019; 139:103850. [PMID: 31706002 DOI: 10.1016/j.micpath.2019.103850] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 10/22/2019] [Accepted: 11/05/2019] [Indexed: 12/11/2022]
Abstract
BACKGROUND Efflux of antibiotics is an effective resistance mechanism among antibiotic-resistant Staphylococcus aureus. This systematic review aims to evaluate the frequency and expression of efflux pump genes in S.aureus around the world. METHOD A comprehensive literature search of several databases (Medline Pub Med, ISI, Scopus, Google Scholar, ISC, Science direct and Persian Journals Online, and citation lists) was performed. We considered published studies from 2001 to 2018. Articles reporting the prevalence and expression of efflux pump genes were selected. RESULT Among 183 articles, 36 studies were selected. Of the 36, 23 articles were conducted in Asia.6 in Europe, 5 in America and 2 in African countries. In most of these studies norA, norB, qacA/B genes were commonly evaluated by molecular methods. The presence of efflux pump genes such as norA, norB, norC, mepA, mdeA, qacA/B was detected by PCR in 21 studies and over-expression of genes were reported in 13 studies. The most frequently reported genes in Asia were norA (75%), norB (60%), mepA (35%), mdeA (33%) and qacA/B (20.8%). In European studies, the prevalence of norB was mostly reported among S.aureus isolates and norA and qacA/B were commonly found in similar studies in America. The investigation of gene expression patterns showed that norA was most frequent single-pattern in Asia and America, norB or mdeA in Europe. CONCLUSION According to this study MDR efflux pumps not only cause high-level resistance but also it considerably associated with over-expression of these genes. Due to the selective pressure on MRSA isolate, the enormous diversity of plasmid-encoded genes had been recorded in different regions, owing to the various numbers and types of isolates in each study or types of disinfectants for general use.
Collapse
|
57
|
Pelling H, Bock LJ, Nzakizwanayo J, Wand ME, Denham EL, MacFarlane WM, Sutton JM, Jones BV. De-repression of the smvA efflux system arises in clinical isolates of Proteus mirabilis and reduces susceptibility to chlorhexidine and other biocides. Antimicrob Agents Chemother 2019; 63:AAC.01535-19. [PMID: 31570392 PMCID: PMC6879213 DOI: 10.1128/aac.01535-19] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 09/18/2019] [Indexed: 01/14/2023] Open
Abstract
Proteus mirabilis is a common pathogen of the catheterised urinary tract and often described as intrinsically resistant to the biocide chlorhexidine (CHD). Here we demonstrate that de-repression of the smvA efflux system has occurred in clinical isolates of P. mirabilis and reduces susceptibility to CHD and other cationic biocides. Compared to other isolates examined, P. mirabilis RS47 exhibited a significantly higher CHD MIC (≥512 μg/ml) and significantly greater expression of smvA. Comparison of the RS47 smvA and cognate smvR repressor with sequences from other isolates, indicated that RS47 encodes an inactivated smvR. Complementation of RS47 with a functional smvR from isolate RS50a (which exhibited the lowest smvA expression and lowest CHD MIC) reduced smvA expression by ∼59-fold, and markedly lowered the MIC of CHD and other cationic biocides. Although complementation of RS47 did not reduce MICs to concentrations observed in isolate RS50a, the significantly lower polymyxin B MIC of RS50a indicated that differences in LPS structure are also a factor in P. mirabilis CHD susceptibility. To determine if exposure to CHD can select for mutations in smvR, clinical isolates with the lowest CHD MICs were adapted to grow at increasing concentrations of CHD up to 512 μg/ml. Analysis of the smvR in adapted populations indicated that mutations predicted to inactivate smvR occurred following CHD exposure in some isolates. Collectively, our data show that smvA de-repression contributes to reduced biocide susceptibility in P. mirabilis, but differences in LPS structure between strains are also likely to be an important factor.
Collapse
Affiliation(s)
- H Pelling
- Dept. of Biology and Biochemistry, University of Bath, Claverton Down, Bath, BA2 7AY, UK
- School of Pharmacy and Biomolecular Sciences, University of Brighton, Brighton, BN2 4GJ, UK
| | - L J Bock
- National Infections Service, Public Health England, Porton Down, Salisbury, SP4 0JG, UK
| | - J Nzakizwanayo
- Dept. of Biology and Biochemistry, University of Bath, Claverton Down, Bath, BA2 7AY, UK
| | - M E Wand
- National Infections Service, Public Health England, Porton Down, Salisbury, SP4 0JG, UK
| | - E L Denham
- Dept. of Biology and Biochemistry, University of Bath, Claverton Down, Bath, BA2 7AY, UK
| | - W M MacFarlane
- School of Pharmacy and Biomolecular Sciences, University of Brighton, Brighton, BN2 4GJ, UK
| | - J M Sutton
- National Infections Service, Public Health England, Porton Down, Salisbury, SP4 0JG, UK
| | - B V Jones
- Dept. of Biology and Biochemistry, University of Bath, Claverton Down, Bath, BA2 7AY, UK
| |
Collapse
|
58
|
Pasqua M, Grossi M, Zennaro A, Fanelli G, Micheli G, Barras F, Colonna B, Prosseda G. The Varied Role of Efflux Pumps of the MFS Family in the Interplay of Bacteria with Animal and Plant Cells. Microorganisms 2019; 7:microorganisms7090285. [PMID: 31443538 PMCID: PMC6780985 DOI: 10.3390/microorganisms7090285] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 08/19/2019] [Accepted: 08/21/2019] [Indexed: 12/20/2022] Open
Abstract
Efflux pumps represent an important and large group of transporter proteins found in all organisms. The importance of efflux pumps resides in their ability to extrude a wide range of antibiotics, resulting in the emergence of multidrug resistance in many bacteria. Besides antibiotics, multidrug efflux pumps can also extrude a large variety of compounds: Bacterial metabolites, plant-produced compounds, quorum-sensing molecules, and virulence factors. This versatility makes efflux pumps relevant players in interactions not only with other bacteria, but also with plant or animal cells. The multidrug efflux pumps belonging to the major facilitator superfamily (MFS) are widely distributed in microbial genomes and exhibit a large spectrum of substrate specificities. Multidrug MFS efflux pumps are present either as single-component transporters or as tripartite complexes. In this review, we will summarize how the multidrug MFS efflux pumps contribute to the interplay between bacteria and targeted host cells, with emphasis on their role in bacterial virulence, in the colonization of plant and animal host cells and in biofilm formation. We will also address the complexity of these interactions in the light of the underlying regulatory networks required for the effective activation of efflux pump genes.
Collapse
Affiliation(s)
- Martina Pasqua
- Istituto Pasteur Italia, Dipartimento di Biologia e Biotecnologie "C. Darwin", Sapienza Università di Roma, Via dei Sardi 70, 00185 Rome, Italy
| | - Milena Grossi
- Istituto Pasteur Italia, Dipartimento di Biologia e Biotecnologie "C. Darwin", Sapienza Università di Roma, Via dei Sardi 70, 00185 Rome, Italy
| | - Alessandro Zennaro
- Istituto Pasteur Italia, Dipartimento di Biologia e Biotecnologie "C. Darwin", Sapienza Università di Roma, Via dei Sardi 70, 00185 Rome, Italy
| | - Giulia Fanelli
- Istituto Pasteur Italia, Dipartimento di Biologia e Biotecnologie "C. Darwin", Sapienza Università di Roma, Via dei Sardi 70, 00185 Rome, Italy
| | - Gioacchino Micheli
- Istituto di Biologia e Patologia Molecolari, Consiglio Nazionale delle Ricerche (CNR), P.le A. Moro 5, 00185 Roma, Italy
| | - Frederic Barras
- Département de Microbiologie, Institut Pasteur, 75015 Paris, France
- Équipe de Recherche Labellisée (ERL) Microbiology, Centre National de la Recherche Scientifique (CNRS), 13009 Marseille, France
| | - Bianca Colonna
- Istituto Pasteur Italia, Dipartimento di Biologia e Biotecnologie "C. Darwin", Sapienza Università di Roma, Via dei Sardi 70, 00185 Rome, Italy
| | - Gianni Prosseda
- Istituto Pasteur Italia, Dipartimento di Biologia e Biotecnologie "C. Darwin", Sapienza Università di Roma, Via dei Sardi 70, 00185 Rome, Italy.
| |
Collapse
|
59
|
Jagessar KL, Mchaourab HS, Claxton DP. The N-terminal domain of an archaeal multidrug and toxin extrusion (MATE) transporter mediates proton coupling required for prokaryotic drug resistance. J Biol Chem 2019; 294:12807-12814. [PMID: 31289123 DOI: 10.1074/jbc.ra119.009195] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Revised: 07/05/2019] [Indexed: 12/15/2022] Open
Abstract
As a contributor to multidrug resistance, the family of multidrug and toxin extrusion (MATE) transporters couples the efflux of chemically dissimilar compounds to electrochemical ion gradients. Although divergent transport mechanisms have been proposed for these transporters, previous structural and functional analyses of members of the MATE subfamily DinF suggest that the N-terminal domain (NTD) supports substrate and ion binding. In this report, we investigated the relationship of ligand binding within the NTD to the drug resistance mechanism of the H+-dependent MATE from the hyperthermophilic archaeon Pyrococcus furiosus (PfMATE). To facilitate this study, we developed a cell growth assay in Escherichia coli to characterize the resistance conferred by PfMATE to toxic concentrations of the antimicrobial compound rhodamine 6G. Expression of WT PfMATE promoted cell growth in the presence of drug, but amino acid substitutions of conserved NTD residues compromised drug resistance. Steady-state binding analysis with purified PfMATE indicated that substrate affinity was unperturbed in these NTD variants. However, exploiting Trp fluorescence as an intrinsic reporter of conformational changes, we found that these variants impaired formation of a unique H+-stabilized structural intermediate. These results imply that disruption of H+ coupling is the origin of compromised toxin resistance in PfMATE variants. These findings support a model mechanism wherein the NTD mediates allosteric coupling to ion gradients through conformational changes to drive substrate transport in PfMATE. Furthermore, the results provide evidence for diverging transport mechanisms within a prokaryotic MATE subfamily.
Collapse
Affiliation(s)
- Kevin L Jagessar
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee 37232
| | - Hassane S Mchaourab
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee 37232
| | - Derek P Claxton
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee 37232
| |
Collapse
|
60
|
Deletion of the major Escherichia coli multidrug transporter AcrB reveals transporter plasticity and redundancy in bacterial cells. PLoS One 2019; 14:e0218828. [PMID: 31251753 PMCID: PMC6599122 DOI: 10.1371/journal.pone.0218828] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2019] [Accepted: 06/11/2019] [Indexed: 12/28/2022] Open
Abstract
Multidrug Transporters (MDTs) are major contributors to the acquisition and maintenance of Antimicrobial Resistance (AMR), a growing public health threat of broad concern. Despite the large number of MDTs, the overwhelming majority of the studies performed thus far in Gram-negative bacteria emphasize the supremacy of the AcrAB-TolC complex. To unveil the potential role of other MDTs we studied the behavior of a null AcrB Escherichia coli strain when challenged with chloramphenicol, a bacteriostatic antibiotic. We found that such a strain developed an extremely high-level of resistance to chloramphenicol, cross resistance to quinolones and erythromycin and displayed high levels of expression of the single component MFS transporter MdfA and multiple TolC-dependent transporters. The results suggest that the high versatility of the whole ensemble of transporters, the bacterial Effluxome, is an essential part of a strategy of survival in everchanging, at times noxious, environments. The concept of a functional Effluxome presents an alternative to the existing paradigms in the field and provides novel targets for the search for inhibitors of transporters as adjuvants of existing antibiotics.
Collapse
|
61
|
The search of potential inhibitors of the AcrAB-TolC system of multidrug-resistant Escherichia coli: an in silico approach. Appl Microbiol Biotechnol 2019; 103:6309-6318. [PMID: 31209525 DOI: 10.1007/s00253-019-09954-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 05/09/2019] [Accepted: 05/28/2019] [Indexed: 01/07/2023]
Abstract
The number of infections caused by multidrug antibiotic resistance (MDR) species is increasing globally. The efflux pump system, AcrAB-TolC, confers Escherichia coli resistance to many antibiotics and results in poor treatment outcomes. Different rational drug design techniques were employed to search for a safe and effective AcrAB-TolC system inhibitor. Ligand docking was performed to analyze the binding of different ArcB substrates and/or inhibitors in the different AcrAB crystal structure binding sites. The validated docking site using the established docking preferences was used to perform virtual high-throughput screening on a large library of compounds. Domperidone, a known and safe over-the-counter antiemetic drug, was proposed as an effective ArcB inhibitor. Microbiological studies confirmed the computational results and domperidone reversed the resistance to the antibiotics: levofloxacin and ciprofloxacin in the MDR E. coli stains with an effect that surpassed the effect of the known efflux pump inhibitor, reserpine. In addition, it was able to increase both antibiotic effects on susceptible strains. This finding suggests that the antibiotic-domperidone combination can be used clinically to treat infections caused by multidrug-resistant E. coli strains.
Collapse
|
62
|
Shi X, Chen M, Yu Z, Bell JM, Wang H, Forrester I, Villarreal H, Jakana J, Du D, Luisi BF, Ludtke SJ, Wang Z. In situ structure and assembly of the multidrug efflux pump AcrAB-TolC. Nat Commun 2019; 10:2635. [PMID: 31201302 PMCID: PMC6570770 DOI: 10.1038/s41467-019-10512-6] [Citation(s) in RCA: 75] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Accepted: 05/08/2019] [Indexed: 11/09/2022] Open
Abstract
Multidrug efflux pumps actively expel a wide range of toxic substrates from the cell and play a major role in intrinsic and acquired drug resistance. In Gram-negative bacteria, these pumps form tripartite assemblies that span the cell envelope. However, the in situ structure and assembly mechanism of multidrug efflux pumps remain unknown. Here we report the in situ structure of the Escherichia coli AcrAB-TolC multidrug efflux pump obtained by electron cryo-tomography and subtomogram averaging. The fully assembled efflux pump is observed in a closed state under conditions of antibiotic challenge and in an open state in the presence of AcrB inhibitor. We also observe intermediate AcrAB complexes without TolC and discover that AcrA contacts the peptidoglycan layer of the periplasm. Our data point to a sequential assembly process in living bacteria, beginning with formation of the AcrAB subcomplex and suggest domains to target with efflux pump inhibitors.
Collapse
Affiliation(s)
- Xiaodong Shi
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, 77030, USA
- Jiangsu Province Key Laboratory of Anesthesiology and Jiangsu Province Key Laboratory of Anesthesia and Analgesia Application, Xuzhou Medical University, Xuzhou, Jiangsu, 221004, China
| | - Muyuan Chen
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Zhili Yu
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, 77030, USA
| | - James M Bell
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, 77030, USA
- Graduate Program in Quantitative and Computational Biosciences, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Hans Wang
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Isaac Forrester
- CryoEM Core at Baylor College of Medicine, Houston, TX, 77030, USA
| | | | - Joanita Jakana
- CryoEM Core at Baylor College of Medicine, Houston, TX, 77030, USA
| | - Dijun Du
- Department of Biochemistry, University of Cambridge, Cambridge, CB21GA, UK
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Ben F Luisi
- Department of Biochemistry, University of Cambridge, Cambridge, CB21GA, UK
| | - Steven J Ludtke
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Zhao Wang
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, 77030, USA.
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas, 77030, USA.
| |
Collapse
|
63
|
Li K, Liu W, Zhao Q, Wu C, Fan C, Lai H, Li S. Combination of tanshinone IIA and doxorubicin possesses synergism and attenuation effects on doxorubicin in the treatment of breast cancer. Phytother Res 2019; 33:1658-1669. [PMID: 30945389 DOI: 10.1002/ptr.6353] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2018] [Revised: 02/04/2019] [Accepted: 03/05/2019] [Indexed: 12/29/2022]
Abstract
Doxorubicin (Dox) is a first-line drug for breast cancer chemotherapy. However, with the prolongation of chemotherapy cycle, breast cancer cells are increasingly tempt to resist Dox, and meanwhile, high cumulative dose of Dox brings enhancing toxic side effects, and these effects may lead to chemotherapy failure. Hence, it is necessary to search an agent in combination medication with Dox, which can not only enhance the chemosensitivity of Dox but also reduce the toxic side effects. Tanshinone IIA (Tan IIA) is reported to have antitumor activity in addition to its cardiovascular protective effects. We employed human breast cancer MCF-7 and MCF-7/dox cells in order to assess whether Tan IIA might perform such function. Our in vitro studies showed that Tan IIA could enhance the sensitivity of breast cancer cells to Dox through inhibiting the PTEN/AKT pathway and downregulating the expression of efflux ABC transporters including P-gp, BCRP, and MRP1. In addition, our in vivo studies showed Tan IIA enhanced the chemotherapeutic effect of Dox against breast cancer while reducing its toxic side effects including weight loss, myelosuppression, cardiotoxicity, and nephrotoxicity. Therefore, Tan IIA could be used as a novel agent combined with Dox in breast cancer therapy.
Collapse
Affiliation(s)
- Kun Li
- Department of Clinical Laboratory, The First Affiliated Hospital of Jinzhou Medical University, Jinzhou, China
| | - Wensu Liu
- School of Life Sciences, China Medical University, Shenyang, China
| | - Qian Zhao
- Department of Clinical Laboratory, The Third Affiliated Hospital of Jinzhou Medical University, Jinzhou, China
| | - Chunxia Wu
- Department of Clinical Laboratory, The First Affiliated Hospital of Jinzhou Medical University, Jinzhou, China
| | - Chenxing Fan
- Department of Clinical Laboratory, The First Affiliated Hospital of Jinzhou Medical University, Jinzhou, China
| | - Hong Lai
- Department of Human Anatomy, China Medical University, Shenyang, China
| | - Shizheng Li
- Department of General Surgery, The First Affiliated Hospital of Jinzhou Medical University, Jinzhou, China
| |
Collapse
|
64
|
Lamut A, Peterlin Mašič L, Kikelj D, Tomašič T. Efflux pump inhibitors of clinically relevant multidrug resistant bacteria. Med Res Rev 2019; 39:2460-2504. [PMID: 31004360 DOI: 10.1002/med.21591] [Citation(s) in RCA: 109] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 03/31/2019] [Accepted: 04/02/2019] [Indexed: 12/29/2022]
Abstract
Bacterial infections are an increasingly serious issue worldwide. The inability of existing therapies to treat multidrug-resistant pathogens has been recognized as an important challenge of the 21st century. Efflux pumps are important in both intrinsic and acquired bacterial resistance and identification of small molecule efflux pump inhibitors (EPIs), capable of restoring the effectiveness of available antibiotics, is an active research field. In the last two decades, much effort has been made to identify novel EPIs. However, none of them has so far been approved for therapeutic use. In this article, we explore different structural families of currently known EPIs for multidrug resistance efflux systems in the most extensively studied pathogens (NorA in Staphylococcus aureus, AcrAB-TolC in Escherichia coli, and MexAB-OprM in Pseudomonas aeruginosa). Both synthetic and natural compounds are described, with structure-activity relationship studies and optimization processes presented systematically for each family individually. In vitro activities against selected test strains are presented in a unifying manner for all the EPIs described, together with the most important toxicity, pharmacokinetic and in vivo efficacy data. A critical evaluation of lead-likeness characteristics and the potential for clinical development of the most promising inhibitors of the three efflux systems is described. This overview of EPIs is a good starting point for the identification of novel effective antibacterial drugs.
Collapse
Affiliation(s)
- Andraž Lamut
- Chair of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Ljubljana, Ljubljana, Slovenia
| | - Lucija Peterlin Mašič
- Chair of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Ljubljana, Ljubljana, Slovenia
| | - Danijel Kikelj
- Chair of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Ljubljana, Ljubljana, Slovenia
| | - Tihomir Tomašič
- Chair of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Ljubljana, Ljubljana, Slovenia
| |
Collapse
|
65
|
Li L, Li J, Zhang Y, Wang N. Diffusible signal factor (DSF)-mediated quorum sensing modulates expression of diverse traits in Xanthomonas citri and responses of citrus plants to promote disease. BMC Genomics 2019; 20:55. [PMID: 30654743 PMCID: PMC6337780 DOI: 10.1186/s12864-018-5384-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2018] [Accepted: 12/18/2018] [Indexed: 01/07/2023] Open
Abstract
Background The gram-negative Xanthomonas genus contains a large group of economically important plant pathogens, which cause severe diseases on many crops worldwide. The diffusible signal factor (DSF) - mediated quorum sensing (QS) system coordinates expression of virulence factors in plant pathogenic Xanthomonas spp. However, the regulatory effects of this system during the Xanthomonas- plant interactions remain unclear from both the pathogen and host aspects. Results In this study, we investigated the in planta DSF- mediated QS regulon of X. citri subsp. citri (Xac), the causal agent of citrus canker. We also characterized the transcriptional responses of citrus plants to DSF-mediated Xac infection via comparing the gene expression patterns of citrus trigged by wild type Xac strain 306 with those trigged by its DSF- deficient (∆rpfF) mutant using the dual RNA-seq approach. Comparative global transcript profiles of Xac strain 306 and the ∆rpfF mutant during host infection revealed that DSF- mediated QS specifically modulates bacterial adaptation, nutrition uptake and metabolisms, stress tolerance, virulence, and signal transduction to favor host infection. The transcriptional responses of citrus to DSF-mediated Xac infection are characterized by downregulation of photosynthesis genes and plant defense related genes, suggesting photosynthetically inactive reactions and repression of defense responses. Alterations of phytohormone metabolism and signaling pathways were also triggered by DSF-mediated Xac infection to benefit the pathogen. Conclusions Collectively, our findings provide new insight into the DSF- mediated QS regulation during plant-pathogen interactions and advance the understanding of traits used by Xanthomonas to promote infection on host plants. Electronic supplementary material The online version of this article (10.1186/s12864-018-5384-4) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Lei Li
- Chinese Academy of Agricultural Sciences, Institute of Vegetables and Flowers, Beijing, 100081, China.,Citrus Research and Education Center, Department of Microbiology and Cell Science, University of Florida, Lake Alfred, FL, 33850, USA
| | - Jinyun Li
- Citrus Research and Education Center, Department of Microbiology and Cell Science, University of Florida, Lake Alfred, FL, 33850, USA
| | - Yunzeng Zhang
- Citrus Research and Education Center, Department of Microbiology and Cell Science, University of Florida, Lake Alfred, FL, 33850, USA
| | - Nian Wang
- Citrus Research and Education Center, Department of Microbiology and Cell Science, University of Florida, Lake Alfred, FL, 33850, USA.
| |
Collapse
|
66
|
Structural Basis of H +-Dependent Conformational Change in a Bacterial MATE Transporter. Structure 2018; 27:293-301.e3. [PMID: 30449688 DOI: 10.1016/j.str.2018.10.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2018] [Revised: 08/07/2018] [Accepted: 10/10/2018] [Indexed: 12/28/2022]
Abstract
Multidrug and toxic compound extrusion (MATE) transporters efflux toxic compounds using a Na+ or H+ gradient across the membrane. Although the structures of MATE transporters have been reported, the cation-coupled substrate transport mechanism remains controversial. Here we report crystal structures of VcmN, a Vibrio cholerae MATE transporter driven by the H+ gradient. High-resolution structures in two distinct conformations associated with different pHs revealed that the rearrangement of the hydrogen-bonding network around the conserved Asp35 induces the bending of transmembrane helix 1, as in the case of the H+-coupled Pyrococcus furiosus MATE transporter. We also determined the crystal structure of the D35N mutant, which captured a unique conformation of TM1 facilitated by an altered hydrogen-bonding network. Based on the present results, we propose a common step in the transport cycle shared among prokaryotic H+-coupled MATE transporters.
Collapse
|
67
|
Fujisaki H, Moritsugu K, Matsunaga Y. Exploring Configuration Space and Path Space of Biomolecules Using Enhanced Sampling Techniques-Searching for Mechanism and Kinetics of Biomolecular Functions. Int J Mol Sci 2018; 19:E3177. [PMID: 30326661 PMCID: PMC6213965 DOI: 10.3390/ijms19103177] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Revised: 10/10/2018] [Accepted: 10/11/2018] [Indexed: 01/07/2023] Open
Abstract
To understand functions of biomolecules such as proteins, not only structures but their conformational change and kinetics need to be characterized, but its atomistic details are hard to obtain both experimentally and computationally. Here, we review our recent computational studies using novel enhanced sampling techniques for conformational sampling of biomolecules and calculations of their kinetics. For efficiently characterizing the free energy landscape of a biomolecule, we introduce the multiscale enhanced sampling method, which uses a combined system of atomistic and coarse-grained models. Based on the idea of Hamiltonian replica exchange, we can recover the statistical properties of the atomistic model without any biases. We next introduce the string method as a path search method to calculate the minimum free energy pathways along a multidimensional curve in high dimensional space. Finally we introduce novel methods to calculate kinetics of biomolecules based on the ideas of path sampling: one is the Onsager⁻Machlup action method, and the other is the weighted ensemble method. Some applications of the above methods to biomolecular systems are also discussed and illustrated.
Collapse
Grants
- JPMJPR1679 Japan Science and Technology Agency
- 16K00059 Ministry of Education, Culture, Sports, Science and Technology
- 17KT0101 Ministry of Education, Culture, Sports, Science and Technology
- 25840060 Ministry of Education, Culture, Sports, Science and Technology
- 15K18520 Ministry of Education, Culture, Sports, Science and Technology
- JP18am0101109 Japan Agency for Medical Research and Development
- 17gm0810012h0001 Japan Agency for Medical Research and Development
Collapse
Affiliation(s)
- Hiroshi Fujisaki
- Department of Physics, Nippon Medical School, 1-7-1 Kyonan-cho, Musashino, Tokyo 180-0023, Japan.
- AMED-CREST, Japan Agency for Medical Research and Development, 1-1-5 Sendagi, Bunkyo-ku, Tokyo 113-8603, Japan.
| | - Kei Moritsugu
- Graduate School of Medical Life Science, Yokohama City University, 1-7-29 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan.
| | - Yasuhiro Matsunaga
- RIKEN Center for Computational Science, 7-1-26 Minatojima-minamimachi, Chuo-ku, Kobe, Hyogo 650-0047, Japan.
- JST PRESTO, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan.
| |
Collapse
|
68
|
Kooger R, Szwedziak P, Böck D, Pilhofer M. CryoEM of bacterial secretion systems. Curr Opin Struct Biol 2018; 52:64-70. [PMID: 30223223 DOI: 10.1016/j.sbi.2018.08.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Revised: 05/18/2018] [Accepted: 08/29/2018] [Indexed: 02/06/2023]
Abstract
The need for bacteria to interact with their environment has driven the evolution of elaborate secretion systems. By virtue of their function, secretion systems are macromolecular complexes associated with the cell envelope and therefore inherently difficult to study by conventional structural biology techniques. Cryo-electron microscopy (cryoEM) has become an invaluable technique to study large membrane-embedded complexes and led to major advances in the mechanistic understanding of secretion systems. CryoEM comprises of two main modalities, namely single particle analysis and tomography. Here, we review how detailed structures retrieved by single particle analysis combine elegantly with tomography experiments in which the secretion systems are observed in their native cellular context.
Collapse
Affiliation(s)
- Romain Kooger
- Institute of Molecular Biology & Biophysics, Eidgenössische Technische Hochschule Zürich, CH-8093 Zürich, Switzerland
| | - Piotr Szwedziak
- Institute of Molecular Biology & Biophysics, Eidgenössische Technische Hochschule Zürich, CH-8093 Zürich, Switzerland
| | - Désirée Böck
- Institute of Molecular Biology & Biophysics, Eidgenössische Technische Hochschule Zürich, CH-8093 Zürich, Switzerland
| | - Martin Pilhofer
- Institute of Molecular Biology & Biophysics, Eidgenössische Technische Hochschule Zürich, CH-8093 Zürich, Switzerland.
| |
Collapse
|
69
|
Agboh K, Lau CHF, Khoo YSK, Singh H, Raturi S, Nair AV, Howard J, Chiapello M, Feret R, Deery MJ, Murakami S, van Veen HW. Powering the ABC multidrug exporter LmrA: How nucleotides embrace the ion-motive force. SCIENCE ADVANCES 2018; 4:eaas9365. [PMID: 30255140 PMCID: PMC6155054 DOI: 10.1126/sciadv.aas9365] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Accepted: 08/02/2018] [Indexed: 05/09/2023]
Abstract
LmrA is a bacterial ATP-binding cassette (ABC) multidrug exporter that uses metabolic energy to transport ions, cytotoxic drugs, and lipids. Voltage clamping in a Port-a-Patch was used to monitor electrical currents associated with the transport of monovalent cationic HEPES+ by single-LmrA transporters and ensembles of transporters. In these experiments, one proton and one chloride ion are effluxed together with each HEPES+ ion out of the inner compartment, whereas two sodium ions are transported into this compartment. Consequently, the sodium-motive force (interior negative and low) can drive this electrogenic ion exchange mechanism in cells under physiological conditions. The same mechanism is also relevant for the efflux of monovalent cationic ethidium, a typical multidrug transporter substrate. Studies in the presence of Mg-ATP (adenosine 5'-triphosphate) show that ion-coupled HEPES+ transport is associated with ATP-bound LmrA, whereas ion-coupled ethidium transport requires ATP binding and hydrolysis. HEPES+ is highly soluble in a water-based environment, whereas ethidium has a strong preference for residence in the water-repelling plasma membrane. We conclude that the mechanism of the ABC transporter LmrA is fundamentally related to that of an ion antiporter that uses extra steps (ATP binding and hydrolysis) to retrieve and transport membrane-soluble substrates from the phospholipid bilayer.
Collapse
Affiliation(s)
- Kelvin Agboh
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, UK
| | - Calvin H. F. Lau
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, UK
| | - Yvonne S. K. Khoo
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, UK
| | - Himansha Singh
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, UK
| | - Sagar Raturi
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, UK
| | - Asha V. Nair
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, UK
| | - Julie Howard
- Cambridge Centre for Proteomics, University of Cambridge, Cambridge CB2 1GA, UK
| | - Marco Chiapello
- Cambridge Centre for Proteomics, University of Cambridge, Cambridge CB2 1GA, UK
| | - Renata Feret
- Cambridge Centre for Proteomics, University of Cambridge, Cambridge CB2 1GA, UK
| | - Michael J. Deery
- Cambridge Centre for Proteomics, University of Cambridge, Cambridge CB2 1GA, UK
| | - Satoshi Murakami
- Department of Life Science and Technology, Tokyo Institute of Technology, Nagatsuta, Midori-ku, Yokohama 226-8501, Japan
| | - Hendrik W. van Veen
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, UK
- Corresponding author.
| |
Collapse
|
70
|
Puvanendran D, Cece Q, Picard M. Reconstitution of the activity of RND efflux pumps: a “bottom-up” approach. Res Microbiol 2018; 169:442-449. [DOI: 10.1016/j.resmic.2017.11.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2017] [Revised: 10/11/2017] [Accepted: 11/20/2017] [Indexed: 11/26/2022]
|
71
|
Felicetti T, Cannalire R, Pietrella D, Latacz G, Lubelska A, Manfroni G, Barreca ML, Massari S, Tabarrini O, Kieć-Kononowicz K, Schindler BD, Kaatz GW, Cecchetti V, Sabatini S. 2-Phenylquinoline S. aureus NorA Efflux Pump Inhibitors: Evaluation of the Importance of Methoxy Group Introduction. J Med Chem 2018; 61:7827-7848. [PMID: 30067360 DOI: 10.1021/acs.jmedchem.8b00791] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Antimicrobial resistance (AMR) represents a hot topic in drug discovery. Besides the identification of new antibiotics, the use of nonantibiotic molecules to block resistance mechanisms is a powerful alternative. Bacterial efflux pumps exert an early step in AMR development by allowing bacteria to grow at subinhibitorial drug concentrations. Thus, efflux pump inhibitors (EPIs) offer a great opportunity to fight AMR. Given our experience in developing Staphylococcus aureus NorA EPIs, in this work, starting from the 2-phenylquinoline hit 1, we planned the introduction of methoxy groups on the basis of their presence in known NorA EPIs. Among the 35 different synthesized derivatives, compounds 3b and 7d exhibited the best NorA inhibition activity by restoring at very low concentrations ciprofloxacin MICs against resistant S. aureus strains. Interestingly, both compounds displayed EPI activities at nontoxic concentrations for human cells as well as highlighted promising results by preliminary pharmacokinetic studies.
Collapse
Affiliation(s)
- Tommaso Felicetti
- Department of Pharmaceutical Sciences , University of Perugia , via del Liceo 1 , 06123 Perugia , Italy
| | - Rolando Cannalire
- Department of Pharmaceutical Sciences , University of Perugia , via del Liceo 1 , 06123 Perugia , Italy
| | - Donatella Pietrella
- Department of Pharmaceutical Sciences , University of Perugia , via del Liceo 1 , 06123 Perugia , Italy
| | - Gniewomir Latacz
- Department of Technology and Biotechnology of Drugs, Faculty of Pharmacy , Jagiellonian University-Medical College , ul. Medyczna 9 , 31-688 Cracow , Poland
| | - Annamaria Lubelska
- Department of Technology and Biotechnology of Drugs, Faculty of Pharmacy , Jagiellonian University-Medical College , ul. Medyczna 9 , 31-688 Cracow , Poland
| | - Giuseppe Manfroni
- Department of Pharmaceutical Sciences , University of Perugia , via del Liceo 1 , 06123 Perugia , Italy
| | - Maria Letizia Barreca
- Department of Pharmaceutical Sciences , University of Perugia , via del Liceo 1 , 06123 Perugia , Italy
| | - Serena Massari
- Department of Pharmaceutical Sciences , University of Perugia , via del Liceo 1 , 06123 Perugia , Italy
| | - Oriana Tabarrini
- Department of Pharmaceutical Sciences , University of Perugia , via del Liceo 1 , 06123 Perugia , Italy
| | - Katarzyna Kieć-Kononowicz
- Department of Technology and Biotechnology of Drugs, Faculty of Pharmacy , Jagiellonian University-Medical College , ul. Medyczna 9 , 31-688 Cracow , Poland
| | - Bryan D Schindler
- John D. Dingell Department of Veterans Affairs Medical Centre and the Department of Internal Medicine, Division of Infectious Diseases, School of Medicine , Wayne State University , Detroit , Michigan 48201 , United States
| | - Glenn W Kaatz
- John D. Dingell Department of Veterans Affairs Medical Centre and the Department of Internal Medicine, Division of Infectious Diseases, School of Medicine , Wayne State University , Detroit , Michigan 48201 , United States
| | - Violetta Cecchetti
- Department of Pharmaceutical Sciences , University of Perugia , via del Liceo 1 , 06123 Perugia , Italy
| | - Stefano Sabatini
- Department of Pharmaceutical Sciences , University of Perugia , via del Liceo 1 , 06123 Perugia , Italy
| |
Collapse
|
72
|
Structural insights into the gating of DNA passage by the topoisomerase II DNA-gate. Nat Commun 2018; 9:3085. [PMID: 30082834 PMCID: PMC6078968 DOI: 10.1038/s41467-018-05406-y] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Accepted: 07/05/2018] [Indexed: 12/11/2022] Open
Abstract
Type IIA topoisomerases (Top2s) manipulate the handedness of DNA crossovers by introducing a transient and protein-linked double-strand break in one DNA duplex, termed the DNA-gate, whose opening allows another DNA segment to be transported through to change the DNA topology. Despite the central importance of this gate-opening event to Top2 function, the DNA-gate in all reported structures of Top2-DNA complexes is in the closed state. Here we present the crystal structure of a human Top2 DNA-gate in an open conformation, which not only reveals structural characteristics of its DNA-conducting path, but also uncovers unexpected yet functionally significant conformational changes associated with gate-opening. This structure further implicates Top2’s preference for a left-handed DNA braid and allows the construction of a model representing the initial entry of another DNA duplex into the DNA-gate. Steered molecular dynamics calculations suggests the Top2-catalyzed DNA passage may be achieved by a rocker-switch-type movement of the DNA-gate. Type II DNA topoisomerases (Top2s) direct the passage of one DNA duplex through another, which is important for resolving DNA entanglements. Here the authors combine X-ray crystallography and MD simulations and present the structure of the human Top2 DNA-gate in an open conformation and discuss mechanistic implications.
Collapse
|
73
|
Johnson WL, Ramachandran A, Torres NJ, Nicholson AC, Whitney AM, Bell M, Villarma A, Humrighouse BW, Sheth M, Dowd SE, McQuiston JR, Gustafson JE. The draft genomes of Elizabethkingia anophelis of equine origin are genetically similar to three isolates from human clinical specimens. PLoS One 2018; 13:e0200731. [PMID: 30024943 PMCID: PMC6053191 DOI: 10.1371/journal.pone.0200731] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Accepted: 05/28/2018] [Indexed: 12/20/2022] Open
Abstract
We report the isolation and characterization of two Elizabethkingia anophelis strains (OSUVM-1 and OSUVM-2) isolated from sources associated with horses in Oklahoma. Both strains appeared susceptible to fluoroquinolones and demonstrated high MICs to all cell wall active antimicrobials including vancomycin, along with aminoglycosides, fusidic acid, chloramphenicol, and tetracycline. Typical of the Elizabethkingia, both draft genomes contained multiple copies of β-lactamase genes as well as genes predicted to function in antimicrobial efflux. Phylogenetic analysis of the draft genomes revealed that OSUVM-1 and OSUVM-2 differ by only 6 SNPs and are in a clade with 3 strains of Elizabethkingia anophelis that were responsible for human infections. These findings therefore raise the possibility that Elizabethkingia might have the potential to move between humans and animals in a manner similar to known zoonotic pathogens.
Collapse
Affiliation(s)
- William L. Johnson
- Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, Oklahoma, United States of America
| | - Akhilesh Ramachandran
- Oklahoma Animal Disease Diagnostic Laboratory, Center for Veterinary Health Sciences, Oklahoma State University, Stillwater, Oklahoma, United States of America
- * E-mail: (AR); (JEG)
| | - Nathanial J. Torres
- Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, Oklahoma, United States of America
| | - Ainsley C. Nicholson
- Special Bacteriology Reference Laboratory, Bacterial Special Pathogens Branch, Division of High-Consequence Pathogens and Pathology, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Anne M. Whitney
- Special Bacteriology Reference Laboratory, Bacterial Special Pathogens Branch, Division of High-Consequence Pathogens and Pathology, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Melissa Bell
- Special Bacteriology Reference Laboratory, Bacterial Special Pathogens Branch, Division of High-Consequence Pathogens and Pathology, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Aaron Villarma
- Special Bacteriology Reference Laboratory, Bacterial Special Pathogens Branch, Division of High-Consequence Pathogens and Pathology, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Ben W. Humrighouse
- Special Bacteriology Reference Laboratory, Bacterial Special Pathogens Branch, Division of High-Consequence Pathogens and Pathology, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Mili Sheth
- Division of Scientific Resources, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Scot E. Dowd
- Molecular Research DNA Laboratory, Shallowater, Texas, United States of America
| | - John R. McQuiston
- Special Bacteriology Reference Laboratory, Bacterial Special Pathogens Branch, Division of High-Consequence Pathogens and Pathology, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - John E. Gustafson
- Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, Oklahoma, United States of America
- * E-mail: (AR); (JEG)
| |
Collapse
|
74
|
Nuonming P, Khemthong S, Dokpikul T, Sukchawalit R, Mongkolsuk S. Characterization and regulation of AcrABR, a RND-type multidrug efflux system, in Agrobacterium tumefaciens C58. Microbiol Res 2018; 214:146-155. [PMID: 30031477 DOI: 10.1016/j.micres.2018.06.014] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Revised: 06/11/2018] [Accepted: 06/30/2018] [Indexed: 10/28/2022]
Abstract
Agrobacterium tumefaciens AcrR is the transcriptional repressor of the acrABR operon. The AcrAB efflux pump confers resistance to various toxic compounds, including antibiotics [ciprofloxacin (CIP), nalidixic acid (NAL), novobiocin (NOV) and tetracycline (TET)], a detergent [sodium dodecyl sulfate (SDS)] and a biocide [triclosan (TRI)]. The sequence to which AcrR specifically binds in the acrA promoter region was determined by EMSA and DNase I footprinting. The AcrR-DNA interaction was abolished by adding NAL, SDS and TRI. Quantitative real time-PCR analysis showed that induction of the acrA transcript occurred when wild-type cells were exposed to NAL, SDS and TRI. Indole is a signaling molecule that increases the antibiotic resistance of bacteria, at least in part, through activation of efflux pumps. Expression of the A. tumefaciens acrA transcript was also inducible by indole in a dose-dependent manner. Indole induced protection against CIP, NAL and SDS but enhanced susceptibility to NOV and TRI. Additionally, the TET resistance of A. tumefaciens was not apparently modulated by indole. A. tumefaciens AcrAB played a dominant role and was required for tolerance to high levels of the toxic compounds. Understanding the regulation of multidrug efflux pumps and bacterial adaptive responses to intracellular and extracellular signaling molecules for antibiotic resistance is essential. This information will be useful for the rational design of effective treatments for bacterial infection to overcome possible multidrug-resistant pathogens.
Collapse
Affiliation(s)
- Puttamas Nuonming
- Applied Biological Sciences, Chulabhorn Graduate Institute, Lak Si, Bangkok 10210, Thailand
| | - Sasimaporn Khemthong
- Applied Biological Sciences, Chulabhorn Graduate Institute, Lak Si, Bangkok 10210, Thailand
| | - Thanittra Dokpikul
- Environmental Toxicology, Chulabhorn Graduate Institute, Lak Si, Bangkok 10210, Thailand
| | - Rojana Sukchawalit
- Applied Biological Sciences, Chulabhorn Graduate Institute, Lak Si, Bangkok 10210, Thailand; Laboratory of Biotechnology, Chulabhorn Research Institute, Lak Si, Bangkok 10210, Thailand; Center of Excellence on Environmental Health and Toxicology (EHT), Ministry of Education, Bangkok, Thailand.
| | - Skorn Mongkolsuk
- Laboratory of Biotechnology, Chulabhorn Research Institute, Lak Si, Bangkok 10210, Thailand; Center of Excellence on Environmental Health and Toxicology (EHT), Ministry of Education, Bangkok, Thailand; Department of Biotechnology, Faculty of Science, Mahidol University, Bangkok 10400, Thailand
| |
Collapse
|
75
|
Sodium and proton coupling in the conformational cycle of a MATE antiporter from Vibrio cholerae. Proc Natl Acad Sci U S A 2018; 115:E6182-E6190. [PMID: 29915043 DOI: 10.1073/pnas.1802417115] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Secondary active transporters belonging to the multidrug and toxic compound extrusion (MATE) family harness the potential energy of electrochemical ion gradients to export a broad spectrum of cytotoxic compounds, thus contributing to multidrug resistance. The current mechanistic understanding of ion-coupled substrate transport has been informed by a limited set of MATE transporter crystal structures from multiple organisms that capture a 12-transmembrane helix topology adopting similar outward-facing conformations. Although these structures mapped conserved residues important for function, the mechanistic role of these residues in shaping the conformational cycle has not been investigated. Here, we use double-electron electron resonance (DEER) spectroscopy to explore ligand-dependent conformational changes of NorM from Vibrio cholerae (NorM-Vc), a MATE transporter proposed to be coupled to both Na+ and H+ gradients. Distance measurements between spin labels on the periplasmic side of NorM-Vc identified unique structural intermediates induced by binding of Na+, H+, or the substrate doxorubicin. The Na+- and H+-dependent intermediates were associated with distinct conformations of TM1. Site-directed mutagenesis of conserved residues revealed that Na+- and H+-driven conformational changes are facilitated by a network of polar residues in the N-terminal domain cavity, whereas conserved carboxylates buried in the C-terminal domain are critical for stabilizing the drug-bound state. Interpreted in conjunction with doxorubicin binding of mutant NorM-Vc and cell toxicity assays, these results establish the role of ion-coupled conformational dynamics in the functional cycle and implicate H+ in the doxorubicin release mechanism.
Collapse
|
76
|
Bulagonda EP, Manivannan B, Mahalingam N, Lama M, Chanakya PP, Khamari B, Jadhao S, Vasudevan M, Nagaraja V. Comparative genomic analysis of a naturally competent Elizabethkingia anophelis isolated from an eye infection. Sci Rep 2018; 8:8447. [PMID: 29855598 PMCID: PMC5981450 DOI: 10.1038/s41598-018-26874-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Accepted: 05/17/2018] [Indexed: 01/18/2023] Open
Abstract
Elizabethkingia anophelis has now emerged as an opportunistic human pathogen. However, its mechanisms of transmission remain unexplained. Comparative genomic (CG) analysis of E. anopheles endophthalmitis strain surprisingly found from an eye infection patient with twenty-five other E. anophelis genomes revealed its potential to participate in horizontal gene transfer. CG analysis revealed that the study isolate has an open pan genome and has undergone extensive gene rearrangements. We demonstrate that the strain is naturally competent, hitherto not reported in any members of Elizabethkingia. Presence of competence related genes, mobile genetic elements, Type IV, VI secretory systems and a unique virulence factor arylsulfatase suggests a different lineage of the strain. Deciphering the genome of E. anophelis having a reservoir of antibiotic resistance genes and virulence factors associated with diverse human infections may open up avenues to deal with the myriad of its human infections and devise strategies to combat the pathogen.
Collapse
Affiliation(s)
- Eswarappa Pradeep Bulagonda
- Department of Biosciences, Sri Sathya Sai Institute of Higher Learning, Prasanthi Nilayam, Puttaparthi, Andhra Pradesh, India.
| | - Bhavani Manivannan
- Department of Biosciences, Sri Sathya Sai Institute of Higher Learning, Prasanthi Nilayam, Puttaparthi, Andhra Pradesh, India
| | - Niranjana Mahalingam
- Department of Biosciences, Sri Sathya Sai Institute of Higher Learning, Prasanthi Nilayam, Puttaparthi, Andhra Pradesh, India.,Department of Microbiology, Sri Sathya Sai Institute of Higher Medical Sciences, Prasanthigram, Andhra Pradesh, India
| | - Manmath Lama
- Department of Biosciences, Sri Sathya Sai Institute of Higher Learning, Prasanthi Nilayam, Puttaparthi, Andhra Pradesh, India
| | - Pachi Pulusu Chanakya
- Department of Biosciences, Sri Sathya Sai Institute of Higher Learning, Prasanthi Nilayam, Puttaparthi, Andhra Pradesh, India
| | - Balaram Khamari
- Department of Biosciences, Sri Sathya Sai Institute of Higher Learning, Prasanthi Nilayam, Puttaparthi, Andhra Pradesh, India
| | - Sudhir Jadhao
- Bionivid technology Pvt Ltd, 4C-209, 4th cross, Kasturi Nagar, Bengaluru, India
| | - Madavan Vasudevan
- Bionivid technology Pvt Ltd, 4C-209, 4th cross, Kasturi Nagar, Bengaluru, India
| | - Valakunja Nagaraja
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bengaluru, India. .,Jawaharlal Nehru Centre for Advanced Scientific Research, Bengaluru, India.
| |
Collapse
|
77
|
Binenbaum J, Weinstain R, Shani E. Gibberellin Localization and Transport in Plants. TRENDS IN PLANT SCIENCE 2018; 23:410-421. [PMID: 29530380 DOI: 10.1016/j.tplants.2018.02.005] [Citation(s) in RCA: 159] [Impact Index Per Article: 26.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Revised: 01/31/2018] [Accepted: 02/02/2018] [Indexed: 05/20/2023]
Abstract
Distribution patterns and finely-tuned concentration gradients of plant hormones govern plant growth and development. Gibberellin (GA) is a plant hormone regulating key processes in plants; many of them are of significant agricultural importance, such as seed germination, root and shoot elongation, flowering, and fruit patterning. Although studies have demonstrated that GA movement is essential for multiple developmental aspects, how GAs are transported throughout the plant and where exactly they accumulate remain largely unknown. Here, we summarize recent findings from studies of GA movement and localization, and discuss the importance of GA intermediates in long- and short-distance movement. We further review recently identified Arabidopsis GA transporters and highlight their complex specialization and robust functional redundancy in GA transport activity.
Collapse
Affiliation(s)
- Jenia Binenbaum
- School of Plant Sciences and Food Security, Tel Aviv University, Tel Aviv, Israel
| | - Roy Weinstain
- School of Plant Sciences and Food Security, Tel Aviv University, Tel Aviv, Israel
| | - Eilon Shani
- School of Plant Sciences and Food Security, Tel Aviv University, Tel Aviv, Israel.
| |
Collapse
|
78
|
Wang JH, Lu J, Zhang YX, Wu J, Luo Y, Liu H. Metagenomic analysis of antibiotic resistance genes in coastal industrial mariculture systems. BIORESOURCE TECHNOLOGY 2018; 253:235-243. [PMID: 29353751 DOI: 10.1016/j.biortech.2018.01.035] [Citation(s) in RCA: 79] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Revised: 01/04/2018] [Accepted: 01/07/2018] [Indexed: 06/07/2023]
Abstract
The overuse of antibiotics has posed a propagation of antibiotic resistance genes (ARGs) in aquaculture systems. This study firstly explored the ARGs profiles of the typical mariculture farms including conventional and recirculating systems using metagenomics approach. Fifty ARGs subtypes belonging to 21 ARGs types were identified, showing the wide-spectrum profiles of ARGs in the coastal industrial mariculture systems. ARGs with multiple antibiotics resistance have emerged in the mariculure systems. The co-occurrence pattern between ARGs and microbial taxa showed that Proteobacteria and Bacteroidetes were potential dominant hosts of ARGs in the industrial mariculture systems. Typical nitrifying bacteria such as Nitrospinae in mariculture systems also carried with some resistance genes. Relative abundance of ARGs in fish ponds and wastewater treatment units was relatively high. The investigation showed that industrial mariculture systems were important ARGs reservoirs in coastal area, indicating the critical role of recirculating systems in the terms of ARGs pollution control.
Collapse
Affiliation(s)
- Jian-Hua Wang
- Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, Shandong 264003, People's Republic of China
| | - Jian Lu
- Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, Shandong 264003, People's Republic of China.
| | - Yu-Xuan Zhang
- Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, Shandong 264003, People's Republic of China
| | - Jun Wu
- Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining, Qinghai 810008, People's Republic of China
| | - Yongming Luo
- Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, Shandong 264003, People's Republic of China
| | - Hao Liu
- Shandong Oriental Ocean Sci-tech Co. Ltd, Yantai, Shandong 264003, People's Republic of China
| |
Collapse
|
79
|
RND transporters in the living world. Res Microbiol 2018; 169:363-371. [PMID: 29577985 DOI: 10.1016/j.resmic.2018.03.001] [Citation(s) in RCA: 78] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Revised: 02/27/2018] [Accepted: 03/01/2018] [Indexed: 12/22/2022]
Abstract
Transporters of the RND superfamily are well-known as the major drug efflux pumps of Gram-negative bacteria. However, they are widespread in organisms ranging from Archaea to Eukaryotes, and perform diverse functions. This review gives a brief overview of these diverse members of the superfamily with emphasis on their structure and functions.
Collapse
|
80
|
Schuldiner S. The Escherichia coli effluxome. Res Microbiol 2018; 169:357-362. [PMID: 29574104 DOI: 10.1016/j.resmic.2018.02.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Revised: 02/20/2018] [Accepted: 02/20/2018] [Indexed: 11/30/2022]
Abstract
Multidrug transporters function in a coordinated mode to provide an essential first-line defense mechanism that prevents antibiotics from reaching lethal concentrations, until a number of stable efficient adaptations occur that allow survival. Single-component efflux transporters remove the toxic compounds from the cytoplasm to the periplasmic space where TolC-dependent transporters expel them from the cell. The close interaction between the two types of transporters ensures handling of a wide range of xenobiotics and prevents rapid leak of the hydrophobic substrates back into the cell. In this review, we discuss the concept of the bacterial effluxome of the Gram-negative Escherichia coli that is the entire set of transporters expressed at a given time, under defined conditions. The process of identification of its members and the elucidation of the nature of the interactions throw a novel light on the roles of transporters in bacterial physiology and drug resistance development. We anticipate that the concept of an effluxome where each member contributes to the removal of noxious chemicals from the cell should contribute to improving the present strategy of searching for transport inhibitors as adjuvants of existing antibiotics and provide novel targets for this urgent undertaking.
Collapse
Affiliation(s)
- Shimon Schuldiner
- Department of Biological Chemistry, Institute of Life Sciences, Silberman Bldg. 1-339, Edmond J. Safra Campus, Hebrew University of Jerusalem, Givat Ram, Jerusalem, 91904, Israel.
| |
Collapse
|
81
|
Matsunaga Y, Yamane T, Terada T, Moritsugu K, Fujisaki H, Murakami S, Ikeguchi M, Kidera A. Energetics and conformational pathways of functional rotation in the multidrug transporter AcrB. eLife 2018; 7:31715. [PMID: 29506651 PMCID: PMC5839741 DOI: 10.7554/elife.31715] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2017] [Accepted: 02/12/2018] [Indexed: 12/31/2022] Open
Abstract
The multidrug transporter AcrB transports a broad range of drugs out of the cell by means of the proton-motive force. The asymmetric crystal structure of trimeric AcrB suggests a functionally rotating mechanism for drug transport. Despite various supportive forms of evidence from biochemical and simulation studies for this mechanism, the link between the functional rotation and proton translocation across the membrane remains elusive. Here, calculating the minimum free energy pathway of the functional rotation for the complete AcrB trimer, we describe the structural and energetic basis behind the coupling between the functional rotation and the proton translocation at atomic resolution. Free energy calculations show that protonation of Asp408 in the transmembrane portion of the drug-bound protomer drives the functional rotation. The conformational pathway identifies vertical shear motions among several transmembrane helices, which regulate alternate access of water in the transmembrane as well as peristaltic motions that pump drugs in the periplasm.
Collapse
Affiliation(s)
- Yasuhiro Matsunaga
- RIKEN Advanced Institute for Computational Science, Kobe, Japan.,JST PRESTO, Kawaguchi, Japan
| | - Tsutomu Yamane
- Graduate School of Medical Life Science, Yokohama City University, Yokohama, Japan
| | - Tohru Terada
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Kei Moritsugu
- Graduate School of Medical Life Science, Yokohama City University, Yokohama, Japan
| | | | - Satoshi Murakami
- Graduate School of Bioscience & Biotechnology, Tokyo Institute of Technology, Yokohama, Japan
| | - Mitsunori Ikeguchi
- Graduate School of Medical Life Science, Yokohama City University, Yokohama, Japan
| | | |
Collapse
|
82
|
Molecular Basis of Substrate Polyspecificity of the Candida albicans Mdr1p Multidrug/H+ Antiporter. J Mol Biol 2018; 430:682-694. [DOI: 10.1016/j.jmb.2018.01.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Revised: 01/09/2018] [Accepted: 01/09/2018] [Indexed: 12/11/2022]
|
83
|
Hassan KA, Liu Q, Elbourne LDH, Ahmad I, Sharples D, Naidu V, Chan CL, Li L, Harborne SPD, Pokhrel A, Postis VLG, Goldman A, Henderson PJF, Paulsen IT. Pacing across the membrane: the novel PACE family of efflux pumps is widespread in Gram-negative pathogens. Res Microbiol 2018; 169:450-454. [PMID: 29409983 PMCID: PMC6195760 DOI: 10.1016/j.resmic.2018.01.001] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Revised: 11/27/2017] [Accepted: 01/08/2018] [Indexed: 01/28/2023]
Abstract
The proteobacterial antimicrobial compound efflux (PACE) family of transport proteins was only recently described. PACE family transport proteins can confer resistance to a range of biocides used as disinfectants and antiseptics, and are encoded by many important Gram-negative human pathogens. However, we are only just beginning to appreciate the range of functions and the mechanism(s) of transport operating in these proteins. Genes encoding PACE family proteins are typically conserved in the core genomes of bacterial species rather than on recently acquired mobile genetic elements, suggesting that they confer important core functions in addition to biocide resistance. Three-dimensional structural information is not yet available for PACE family proteins. However, PACE proteins have several very highly conserved amino acid sequence motifs that are likely to be important for substrate transport. PACE proteins also display strong amino acid sequence conservation between their N— and C-terminal halves, suggesting that they evolved by duplication of an ancestral protein comprised of two transmembrane helices. In light of their drug resistance functions in Gram-negative pathogens, PACE proteins should be the subject of detailed future investigation.
Collapse
Affiliation(s)
- Karl A Hassan
- School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW, Australia; School of BioMedical Sciences and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, UK; Department of Chemistry and Biomolecular Science, Macquarie University, North Ryde, NSW, Australia.
| | - Qi Liu
- Department of Chemistry and Biomolecular Science, Macquarie University, North Ryde, NSW, Australia
| | - Liam D H Elbourne
- Department of Chemistry and Biomolecular Science, Macquarie University, North Ryde, NSW, Australia
| | - Irshad Ahmad
- School of BioMedical Sciences and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, UK
| | - David Sharples
- School of BioMedical Sciences and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, UK
| | - Varsha Naidu
- Department of Chemistry and Biomolecular Science, Macquarie University, North Ryde, NSW, Australia
| | - Chak Lam Chan
- School of BioMedical Sciences and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, UK
| | - Liping Li
- Department of Chemistry and Biomolecular Science, Macquarie University, North Ryde, NSW, Australia
| | - Steven P D Harborne
- School of BioMedical Sciences and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, UK
| | - Alaska Pokhrel
- Department of Chemistry and Biomolecular Science, Macquarie University, North Ryde, NSW, Australia
| | - Vincent L G Postis
- School of BioMedical Sciences and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, UK; Biomedicine Research Group, Faculty of Health and Social Sciences, Leeds Beckett University, Leeds, UK
| | - Adrian Goldman
- School of BioMedical Sciences and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, UK; Division of Biochemistry, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Peter J F Henderson
- School of BioMedical Sciences and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, UK
| | - Ian T Paulsen
- Department of Chemistry and Biomolecular Science, Macquarie University, North Ryde, NSW, Australia
| |
Collapse
|
84
|
Slipski CJ, Zhanel GG, Bay DC. Biocide Selective TolC-Independent Efflux Pumps in Enterobacteriaceae. J Membr Biol 2018; 251:15-33. [PMID: 29063140 PMCID: PMC5840245 DOI: 10.1007/s00232-017-9992-8] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Accepted: 10/04/2017] [Indexed: 02/03/2023]
Abstract
Bacterial resistance to biocides used as antiseptics, dyes, and disinfectants is a growing concern in food preparation, agricultural, consumer manufacturing, and health care industries, particularly among Gram-negative Enterobacteriaceae, some of the most common community and healthcare-acquired bacterial pathogens. Biocide resistance is frequently associated with antimicrobial cross-resistance leading to reduced activity and efficacy of both antimicrobials and antiseptics. Multidrug resistant efflux pumps represent an important biocide resistance mechanism in Enterobacteriaceae. An assortment of structurally diverse efflux pumps frequently co-exist in these species and confer both unique and overlapping biocide and antimicrobial selectivity. TolC-dependent multicomponent systems that span both the plasma and outer membranes have been shown to confer clinically significant resistance to most antimicrobials including many biocides, however, a growing number of single component TolC-independent multidrug resistant efflux pumps are specifically associated with biocide resistance: small multidrug resistance (SMR), major facilitator superfamily (MFS), multidrug and toxin extruder (MATE), cation diffusion facilitator (CDF), and proteobacterial antimicrobial compound efflux (PACE) families. These efflux systems are a growing concern as they are rapidly spread between members of Enterobacteriaceae on conjugative plasmids and mobile genetic elements, emphasizing their importance to antimicrobial resistance. In this review, we will summarize the known biocide substrates of these efflux pumps, compare their structural relatedness, Enterobacteriaceae distribution, and significance. Knowledge gaps will be highlighted in an effort to unravel the role that these apparent "lone wolves" of the efflux-mediated resistome may offer.
Collapse
Affiliation(s)
- Carmine J Slipski
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Rm 514C Basic Medical Sciences Bldg., 745 Bannatyne Avenue, Winnipeg, MB, R3E 0J9, Canada
| | - George G Zhanel
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Rm 514C Basic Medical Sciences Bldg., 745 Bannatyne Avenue, Winnipeg, MB, R3E 0J9, Canada
| | - Denice C Bay
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Rm 514C Basic Medical Sciences Bldg., 745 Bannatyne Avenue, Winnipeg, MB, R3E 0J9, Canada.
| |
Collapse
|
85
|
Vargiu AV, Ramaswamy VK, Malloci G, Malvacio I, Atzori A, Ruggerone P. Computer simulations of the activity of RND efflux pumps. Res Microbiol 2018; 169:384-392. [PMID: 29407044 DOI: 10.1016/j.resmic.2017.12.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 12/01/2017] [Accepted: 12/05/2017] [Indexed: 12/25/2022]
Abstract
The putative mechanism by which bacterial RND-type multidrug efflux pumps recognize and transport their substrates is a complex and fascinating enigma of structural biology. How a single protein can recognize a huge number of unrelated compounds and transport them through one or just a few mechanisms is an amazing feature not yet completely unveiled. The appearance of cooperativity further complicates the understanding of structure-dynamics-activity relationships in these complex machineries. Experimental techniques may have limited access to the molecular determinants and to the energetics of key processes regulating the activity of these pumps. Computer simulations are a complementary approach that can help unveil these features and inspire new experiments. Here we review recent computational studies that addressed the various molecular processes regulating the activity of RND efflux pumps.
Collapse
Affiliation(s)
- Attilio Vittorio Vargiu
- Department of Physics, University of Cagliari, Cittadella Universitaria, S.P. Monserrato-Sestu km 0.700, 09042 Monserrato (CA), Italy.
| | - Venkata Krishnan Ramaswamy
- Department of Physics, University of Cagliari, Cittadella Universitaria, S.P. Monserrato-Sestu km 0.700, 09042 Monserrato (CA), Italy
| | - Giuliano Malloci
- Department of Physics, University of Cagliari, Cittadella Universitaria, S.P. Monserrato-Sestu km 0.700, 09042 Monserrato (CA), Italy
| | - Ivana Malvacio
- Department of Physics, University of Cagliari, Cittadella Universitaria, S.P. Monserrato-Sestu km 0.700, 09042 Monserrato (CA), Italy
| | - Alessio Atzori
- Department of Physics, University of Cagliari, Cittadella Universitaria, S.P. Monserrato-Sestu km 0.700, 09042 Monserrato (CA), Italy
| | - Paolo Ruggerone
- Department of Physics, University of Cagliari, Cittadella Universitaria, S.P. Monserrato-Sestu km 0.700, 09042 Monserrato (CA), Italy.
| |
Collapse
|
86
|
Leninger M, Traaseth NJ. NMR Spectroscopy Approach to Study the Structure, Orientation, and Mechanism of the Multidrug Exporter EmrE. Methods Mol Biol 2018; 1700:83-96. [PMID: 29177827 PMCID: PMC5926179 DOI: 10.1007/978-1-4939-7454-2_6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Multidrug exporters are a class of membrane proteins that remove antibiotics from the cytoplasm of bacteria and in the process confer multidrug resistance to the organism. This chapter outlines the sample preparation and optimization of oriented solid-state NMR experiments applied to the study of structure and dynamics for the model transporter EmrE from the small multidrug resistance (SMR) family.
Collapse
Affiliation(s)
- Maureen Leninger
- Department of Chemistry, New York University, 100 Washington Square East, New York, NY, 10003, USA
| | - Nathaniel J Traaseth
- Department of Chemistry, New York University, 100 Washington Square East, New York, NY, 10003, USA.
| |
Collapse
|
87
|
Pagès JM. [Antibiotic transport and membrane permeability: new insights to fight bacterial resistance]. Biol Aujourdhui 2017; 211:149-154. [PMID: 29236663 DOI: 10.1051/jbio/2017020] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Indexed: 11/14/2022]
Abstract
A main challenge in medicinal chemistry is to determine the parameters modulating the in cellulo drug concentration needed for a therapeutic action. In Gram-negative antibacterial research, the concern is to evaluate the antibiotic permeation across the outer and inner membranes, that delineate the periplasm surrounding the bacterial cytoplasm. Passing through the membrane barrier to reach the inhibitory concentration inside the bacterium is the first pivotal step for antibiotics. The research and the development of new antimicrobials mostly rely on their capacity to reach critical concentrations in the vicinity of their intracellular target. Despite several decades of studies focused on antibiotic/drug activity against bacterial cells using different approaches, no consensus regarding the analysis of the kinetics and accumulation in individual bacterium and in bacterial populations is available to understand the drug translocation into living bacteria as a first step of drug action. Our TRANSLOCATION consortium supports the development of reliable and robust methods to quantify penetration and efflux processes in Gram-negative bacteria and recently we have developed a reliable and efficient method to determine the intra-bacterial concentration of fluorescent antibiotics. By using these powerful approaches, new concepts, "Resident Time Concentration Close to Target" (RTC2T) and "Structure Intracellular Concentration Activity Relationship" (SICAR), have been proposed in order to link chemical and structural aspects with the bacterial membrane and transport aspects. Using RTC2T and SICAR indexes, a new dissection of antibiotic translocation-transport can be obtained to better understand and improve the antibiotic pharmacophoric groups that are related to permeation and efflux.
Collapse
Affiliation(s)
- Jean-Marie Pagès
- UMR_MD1, Transporteurs Membranaires, Chimiorésistance et Drug Design, Faculté de Médecine et Faculté de Pharmacie, 27 boulevard Jean-Moulin, 13385 Marseille cedex 05, France
| |
Collapse
|
88
|
López CA, Travers T, Pos KM, Zgurskaya HI, Gnanakaran S. Dynamics of Intact MexAB-OprM Efflux Pump: Focusing on the MexA-OprM Interface. Sci Rep 2017; 7:16521. [PMID: 29184094 PMCID: PMC5705723 DOI: 10.1038/s41598-017-16497-w] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Accepted: 10/30/2017] [Indexed: 11/30/2022] Open
Abstract
Antibiotic efflux is one of the most critical mechanisms leading to bacterial multidrug resistance. Antibiotics are effluxed out of the bacterial cell by a tripartite efflux pump, a complex machinery comprised of outer membrane, periplasmic adaptor, and inner membrane protein components. Understanding the mechanism of efflux pump assembly and its dynamics could facilitate discovery of novel approaches to counteract antibiotic resistance in bacteria. We built here an intact atomistic model of the Pseudomonas aeruginosa MexAB-OprM pump in a Gram-negative membrane model that contained both inner and outer membranes separated by a periplasmic space. All-atom molecular dynamics (MD) simulations confirm that the fully assembled pump is stable in the microsecond timescale. Using a combination of all-atom and coarse-grained MD simulations and sequence covariation analysis, we characterized the interface between MexA and OprM in the context of the entire efflux pump. These analyses suggest a plausible mechanism by which OprM is activated via opening of its periplasmic aperture through a concerted interaction with MexA.
Collapse
Affiliation(s)
- Cesar A López
- Theoretical Biology and Biophysics Group, Los Alamos National Laboratory, Los Alamos, New Mexico, 87545, United States
| | - Timothy Travers
- Theoretical Biology and Biophysics Group, Los Alamos National Laboratory, Los Alamos, New Mexico, 87545, United States.,Center for Nonlinear Sciences, Los Alamos National Laboratory, Los Alamos, New Mexico, 87545, United States
| | - Klaas M Pos
- Institute of Biochemistry, Goethe University, Frankfurt am Main, Germany.,Cluster of Excellence Frankfurt, Goethe University, Frankfurt am Main, Germany
| | - Helen I Zgurskaya
- Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Parkway, Norman, Oklahoma, 73019, United States
| | - S Gnanakaran
- Theoretical Biology and Biophysics Group, Los Alamos National Laboratory, Los Alamos, New Mexico, 87545, United States.
| |
Collapse
|
89
|
Yue Z, Chen W, Zgurskaya HI, Shen J. Constant pH Molecular Dynamics Reveals How Proton Release Drives the Conformational Transition of a Transmembrane Efflux Pump. J Chem Theory Comput 2017; 13:6405-6414. [PMID: 29117682 DOI: 10.1021/acs.jctc.7b00874] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
AcrB is the inner-membrane transporter of an E. coli AcrAB-TolC tripartite efflux complex, which plays a major role in the intrinsic resistance to clinically important antibiotics. AcrB pumps a wide range of toxic substrates by utilizing the proton gradient between periplasm and cytoplasm. Crystal structures of AcrB revealed three distinct conformational states of the transport cycle, substrate access, binding, and extrusion or loose (L), tight (T), and open (O) states. However, the specific residue(s) responsible for proton binding/release and the mechanism of proton-coupled conformational cycling remain controversial. Here we use the newly developed membrane hybrid-solvent continuous constant pH molecular dynamics technique to explore the protonation states and conformational dynamics of the transmembrane domain of AcrB. Simulations show that both Asp407 and Asp408 are deprotonated in the L/T states, while only Asp408 is protonated in the O state. Remarkably, release of a proton from Asp408 in the O state results in large conformational changes, such as the lateral and vertical movement of transmembrane helices as well as the salt-bridge formation between Asp408 and Lys940 and other side chain rearrangements among essential residues. Consistent with the crystallographic differences between the O and L protomers, simulations offer dynamic details of how proton release drives the O-to-L transition in AcrB and address the controversy regarding the proton/drug stoichiometry. This work offers a significant step toward characterizing the complete cycle of proton-coupled drug transport in AcrB and further validates the membrane hybrid-solvent CpHMD technique for studies of proton-coupled transmembrane proteins which are currently poorly understood.
Collapse
Affiliation(s)
- Zhi Yue
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy , Baltimore, Maryland 21201, United States
| | | | - Helen I Zgurskaya
- Department of Chemistry and Biochemistry, University of Oklahoma , Norman, Oklahoma 73019, United States
| | - Jana Shen
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy , Baltimore, Maryland 21201, United States
| |
Collapse
|
90
|
Crystal structure of tripartite-type ABC transporter MacB from Acinetobacter baumannii. Nat Commun 2017; 8:1336. [PMID: 29109439 PMCID: PMC5673888 DOI: 10.1038/s41467-017-01399-2] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2017] [Accepted: 09/13/2017] [Indexed: 01/17/2023] Open
Abstract
The MacA-MacB-TolC tripartite complex is a transmembrane machine that spans both plasma membrane and outer membrane and actively extrudes substrates, including macrolide antibiotics, virulence factors, peptides and cell envelope precursors. These transport activities are driven by the ATPase MacB, a member of the ATP-binding cassette (ABC) superfamily. Here, we present the crystal structure of MacB at 3.4-Å resolution. MacB forms a dimer in which each protomer contains a nucleotide-binding domain and four transmembrane helices that protrude in the periplasm into a binding domain for interaction with the membrane fusion protein MacA. MacB represents an ABC transporter in pathogenic microorganisms with unique structural features.
Collapse
|
91
|
Type I Protein Secretion-Deceptively Simple yet with a Wide Range of Mechanistic Variability across the Family. EcoSal Plus 2017; 7. [PMID: 28084193 DOI: 10.1128/ecosalplus.esp-0019-2015] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
A very large type I polypeptide begins to reel out from a ribosome; minutes later, the still unidentifiable polypeptide, largely lacking secondary structure, is now in some cases a thousand or more residues longer. Synthesis of the final hundred C-terminal residues commences. This includes the identity code, the secretion signal within the last 50 amino acids, designed to dock with a waiting ATP binding cassette (ABC) transporter. What happens next is the subject of this review, with the main, but not the only focus on hemolysin HlyA, an RTX protein toxin secreted by the type I system. Transport substrates range from small peptides to giant proteins produced by many pathogens. These molecules, without detectable cellular chaperones, overcome enormous barriers, crossing two membranes before final folding on the cell surface, involving a unique autocatalytic process.Unfolded HlyA is extruded posttranslationally, C-terminal first. The transenvelope "tunnel" is formed by HlyB (ABC transporter), HlyD (membrane fusion protein) straddling the inner membrane and periplasm and TolC (outer membrane). We present a new evaluation of the C-terminal secretion code, and the structure function of HlyD and HlyB at the heart of this nanomachine. Surprisingly, key details of the secretion mechanism are remarkably variable in the many type I secretion system subtypes. These include alternative folding processes, an apparently distinctive secretion code for each type I subfamily, and alternative forms of the ABC transporter; most remarkably, the ABC protein probably transports peptides or polypeptides by quite different mechanisms. Finally, we suggest a putative structure for the Hly-translocon, HlyB, the multijointed HlyD, and the TolC exit.
Collapse
|
92
|
Zwama M, Hayashi K, Sakurai K, Nakashima R, Kitagawa K, Nishino K, Yamaguchi A. Hoisting-Loop in Bacterial Multidrug Exporter AcrB Is a Highly Flexible Hinge That Enables the Large Motion of the Subdomains. Front Microbiol 2017; 8:2095. [PMID: 29118749 PMCID: PMC5661021 DOI: 10.3389/fmicb.2017.02095] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Accepted: 10/12/2017] [Indexed: 01/21/2023] Open
Abstract
The overexpression of RND-type exporters is one of the main causes of multidrug resistance (MDR) in Gram-negative pathogens. In RND transporters, such as Escherichia coli's main efflux pump AcrB, drug efflux occurs in the porter domain, while protons flow through the transmembrane domain: remote conformational coupling. At the border of a transmembrane helix (TM8) and subdomain PC2, there is a loop which makes a hoisting movement by a random-coil-to-α-helix change, and opens and closes a drug channel entrance. This loop is supposed to play a key role in the allosteric conformational coupling between the transmembrane and porter domain. Here we show the results of a series of flexibility loop-mutants of AcrB. We determined the crystal structure of a three amino acid truncated loop mutant, which is still a functional transporter, and show that the short α-helix between Cβ15 and the loop unwinds to a random coil in the access and binding monomers and in the extrusion monomer it makes a partially stretched coil-to-helix change. The loop has undergone compensatory conformational changes and still facilitates the opening and closing of the channel. In addition, more flexible mutated loops (proline mutated and significantly elongated) can still function during export. The flexibility in this region is however limited, as an even more truncated mutant (six amino acid deletion) becomes mostly inactive. We found that the hoisting-loop is a highly flexible hinge that enables the conformational energy transmission passively.
Collapse
Affiliation(s)
- Martijn Zwama
- Department of Cell Membrane Structural Biology, Institute of Scientific and Industrial Research, Osaka University, Osaka, Japan.,Department of Biomolecular Science and Regulation, Institute of Scientific and Industrial Research, Osaka University, Osaka, Japan.,Graduate School of Pharmaceutical Sciences, Osaka University, Osaka, Japan
| | - Katsuhiko Hayashi
- Department of Cell Membrane Structural Biology, Institute of Scientific and Industrial Research, Osaka University, Osaka, Japan.,Department of Biomolecular Science and Regulation, Institute of Scientific and Industrial Research, Osaka University, Osaka, Japan
| | - Keisuke Sakurai
- Department of Cell Membrane Structural Biology, Institute of Scientific and Industrial Research, Osaka University, Osaka, Japan
| | - Ryosuke Nakashima
- Department of Cell Membrane Structural Biology, Institute of Scientific and Industrial Research, Osaka University, Osaka, Japan
| | - Kimie Kitagawa
- Department of Cell Membrane Structural Biology, Institute of Scientific and Industrial Research, Osaka University, Osaka, Japan
| | - Kunihiko Nishino
- Department of Biomolecular Science and Regulation, Institute of Scientific and Industrial Research, Osaka University, Osaka, Japan
| | - Akihito Yamaguchi
- Department of Cell Membrane Structural Biology, Institute of Scientific and Industrial Research, Osaka University, Osaka, Japan
| |
Collapse
|
93
|
Clamping down on drugs: the Escherichia coli multidrug efflux protein MdtM. Res Microbiol 2017; 169:461-467. [PMID: 28962921 DOI: 10.1016/j.resmic.2017.09.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Revised: 09/19/2017] [Accepted: 09/21/2017] [Indexed: 11/22/2022]
Abstract
Multidrug resistance is principally a consequence of the active transport of drugs out of the cell by proteins that are integral membrane transporters. In the following review, we present a synthesis of current understanding of the Escherichia coli multidrug resistance transporter, MdtM, a 410 amino acid residue protein that belongs to the large and ubiquitous major facilitator superfamily (MFS).
Collapse
|
94
|
Krah A, Zachariae U. Insights into the ion-coupling mechanism in the MATE transporter NorM-VC. Phys Biol 2017; 14:045009. [DOI: 10.1088/1478-3975/aa5ee7] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
95
|
Wang Z, Fan G, Hryc CF, Blaza JN, Serysheva II, Schmid MF, Chiu W, Luisi BF, Du D. An allosteric transport mechanism for the AcrAB-TolC multidrug efflux pump. eLife 2017; 6. [PMID: 28355133 PMCID: PMC5404916 DOI: 10.7554/elife.24905] [Citation(s) in RCA: 153] [Impact Index Per Article: 21.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Accepted: 03/14/2017] [Indexed: 12/12/2022] Open
Abstract
Bacterial efflux pumps confer multidrug resistance by transporting diverse antibiotics from the cell. In Gram-negative bacteria, some of these pumps form multi-protein assemblies that span the cell envelope. Here, we report the near-atomic resolution cryoEM structures of the Escherichia coli AcrAB-TolC multidrug efflux pump in resting and drug transport states, revealing a quaternary structural switch that allosterically couples and synchronizes initial ligand binding with channel opening. Within the transport-activated state, the channel remains open even though the pump cycles through three distinct conformations. Collectively, our data provide a dynamic mechanism for the assembly and operation of the AcrAB-TolC pump. DOI:http://dx.doi.org/10.7554/eLife.24905.001
Collapse
Affiliation(s)
- Zhao Wang
- National Center for Macromolecular Imaging, Baylor College of Medicine, Houston, United States.,Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, United States
| | - Guizhen Fan
- Department of Biochemistry and Molecular Biology, Structural Biology Imaging Center, The University of Texas Health Science Center at Houston Medical School, Houston, United States
| | - Corey F Hryc
- National Center for Macromolecular Imaging, Baylor College of Medicine, Houston, United States.,Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, United States.,Graduate Program in Structural and Computational Biology and Molecular Biophysics, Baylor College of Medicine, Houston, United States
| | - James N Blaza
- MRC Mitochondrial Biology Unit, Cambridge Biomedical Campus, Cambridge, United Kingdom
| | - Irina I Serysheva
- Department of Biochemistry and Molecular Biology, Structural Biology Imaging Center, The University of Texas Health Science Center at Houston Medical School, Houston, United States
| | - Michael F Schmid
- National Center for Macromolecular Imaging, Baylor College of Medicine, Houston, United States.,Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, United States
| | - Wah Chiu
- National Center for Macromolecular Imaging, Baylor College of Medicine, Houston, United States.,Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, United States.,Graduate Program in Structural and Computational Biology and Molecular Biophysics, Baylor College of Medicine, Houston, United States
| | - Ben F Luisi
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Dijun Du
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| |
Collapse
|
96
|
Ansell BRE, Baker L, Emery SJ, McConville MJ, Svärd SG, Gasser RB, Jex AR. Transcriptomics Indicates Active and Passive Metronidazole Resistance Mechanisms in Three Seminal Giardia Lines. Front Microbiol 2017; 8:398. [PMID: 28367140 PMCID: PMC5355454 DOI: 10.3389/fmicb.2017.00398] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Accepted: 02/27/2017] [Indexed: 12/13/2022] Open
Abstract
Giardia duodenalis is an intestinal parasite that causes 200-300 million episodes of diarrhoea annually. Metronidazole (Mtz) is a front-line anti-giardial, but treatment failure is common and clinical resistance has been demonstrated. Mtz is thought to be activated within the parasite by oxidoreductase enzymes, and to kill by causing oxidative damage. In G. duodenalis, Mtz resistance involves active and passive mechanisms. Relatively low activity of iron-sulfur binding proteins, namely pyruvate:ferredoxin oxidoreductase (PFOR), ferredoxins, and nitroreductase-1, enable resistant cells to passively avoid Mtz activation. Additionally, low expression of oxygen-detoxification enzymes can allow passive (non-enzymatic) Mtz detoxification via futile redox cycling. In contrast, active resistance mechanisms include complete enzymatic detoxification of the pro-drug by nitroreductase-2 and enhanced repair of oxidized biomolecules via thioredoxin-dependent antioxidant enzymes. Molecular resistance mechanisms may be largely founded on reversible transcriptional changes, as some resistant lines revert to drug sensitivity during drug-free culture in vitro, or passage through the life cycle. To comprehensively characterize these changes, we undertook strand-specific RNA sequencing of three laboratory-derived Mtz-resistant lines, 106-2ID10, 713-M3, and WB-M3, and compared transcription relative to their susceptible parents. Common up-regulated genes encoded variant-specific surface proteins (VSPs), a high cysteine membrane protein, calcium and zinc channels, a Mad-2 cell cycle regulator and a putative fatty acid α-oxidase. Down-regulated genes included nitroreductase-1, putative chromate and quinone reductases, and numerous genes that act proximal to PFOR. Transcriptional changes in 106-2ID10 diverged from those in 713-r and WB-r (r ≤ 0.2), which were more similar to each other (r = 0.47). In 106-2ID10, a nonsense mutation in nitroreductase-1 transcripts could enhance passive resistance whereas increased transcription of nitroreductase-2, and a MATE transmembrane pump system, suggest active drug detoxification and efflux, respectively. By contrast, transcriptional changes in 713-M3 and WB-M3 indicated a higher oxidative stress load, attributed to Mtz- and oxygen-derived radicals, respectively. Quantitative comparisons of orthologous gene transcription between Mtz-resistant G. duodenalis and Trichomonas vaginalis, a closely related parasite, revealed changes in transcripts encoding peroxidases, heat shock proteins, and FMN-binding oxidoreductases, as prominent correlates of resistance. This work provides deep insight into Mtz-resistant G. duodenalis, and illuminates resistance-associated features across parasitic species.
Collapse
Affiliation(s)
- Brendan R. E. Ansell
- Faculty of Veterinary and Agricultural Sciences, The University of MelbourneMelbourne, VIC, Australia
| | - Louise Baker
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical ResearchMelbourne, VIC, Australia
| | - Samantha J. Emery
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical ResearchMelbourne, VIC, Australia
| | - Malcolm J. McConville
- Bio21 Molecular Science and Biotechnology Institute, The University of MelbourneMelbourne, VIC, Australia
| | - Staffan G. Svärd
- Department of Cell and Molecular Biology, Uppsala UniversityUppsala, Sweden
| | - Robin B. Gasser
- Faculty of Veterinary and Agricultural Sciences, The University of MelbourneMelbourne, VIC, Australia
| | - Aaron R. Jex
- Faculty of Veterinary and Agricultural Sciences, The University of MelbourneMelbourne, VIC, Australia
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical ResearchMelbourne, VIC, Australia
| |
Collapse
|
97
|
Spengler G, Kincses A, Gajdács M, Amaral L. New Roads Leading to Old Destinations: Efflux Pumps as Targets to Reverse Multidrug Resistance in Bacteria. Molecules 2017; 22:molecules22030468. [PMID: 28294992 PMCID: PMC6155429 DOI: 10.3390/molecules22030468] [Citation(s) in RCA: 118] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 03/09/2017] [Accepted: 03/10/2017] [Indexed: 01/05/2023] Open
Abstract
Multidrug resistance (MDR) has appeared in response to selective pressures resulting from the incorrect use of antibiotics and other antimicrobials. This inappropriate application and mismanagement of antibiotics have led to serious problems in the therapy of infectious diseases. Bacteria can develop resistance by various mechanisms and one of the most important factors resulting in MDR is efflux pump-mediated resistance. Because of the importance of the efflux-related multidrug resistance the development of new therapeutic approaches aiming to inhibit bacterial efflux pumps is a promising way to combat bacteria having over-expressed MDR efflux systems. The definition of an efflux pump inhibitor (EPI) includes the ability to render the bacterium increasingly more sensitive to a given antibiotic or even reverse the multidrug resistant phenotype. In the recent years numerous EPIs have been developed, although so far their clinical application has not yet been achieved due to their in vivo toxicity and side effects. In this review, we aim to give a short overview of efflux mediated resistance in bacteria, EPI compounds of plant and synthetic origin, and the possible methods to investigate and screen EPI compounds in bacterial systems.
Collapse
Affiliation(s)
- Gabriella Spengler
- Department of Medical Microbiology and Immunobiology, Faculty of Medicine, University of Szeged, 6720 Szeged, Hungary.
| | - Annamária Kincses
- Department of Medical Microbiology and Immunobiology, Faculty of Medicine, University of Szeged, 6720 Szeged, Hungary.
| | - Márió Gajdács
- Department of Medical Microbiology and Immunobiology, Faculty of Medicine, University of Szeged, 6720 Szeged, Hungary.
| | - Leonard Amaral
- Department of Medical Microbiology and Immunobiology, Faculty of Medicine, University of Szeged, 6720 Szeged, Hungary.
- Travel Medicine, Institute of Hygiene and Tropical Medicine, Universidade Nova de Lisboa, 1349-008 Lisbon, Portugal.
| |
Collapse
|
98
|
The role played by drug efflux pumps in bacterial multidrug resistance. Essays Biochem 2017; 61:127-139. [DOI: 10.1042/ebc20160064] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Revised: 01/22/2017] [Accepted: 01/24/2017] [Indexed: 01/19/2023]
Abstract
Antimicrobial resistance is a current major challenge in chemotherapy and infection control. The ability of bacterial and eukaryotic cells to recognize and pump toxic compounds from within the cell to the environment before they reach their targets is one of the important mechanisms contributing to this phenomenon. Drug efflux pumps are membrane transport proteins that require energy to export substrates and can be selective for a specific drug or poly-specific that can export multiple structurally diverse drug compounds. These proteins can be classified into seven groups based on protein sequence homology, energy source and overall structure. Extensive studies on efflux proteins have resulted in a wealth of knowledge that has made possible in-depth understanding of the structures and mechanisms of action, substrate profiles, regulation and possible inhibition of many clinically important efflux pumps. This review focuses on describing known families of drug efflux pumps using examples that are well characterized structurally and/or biochemically.
Collapse
|
99
|
Computational modelling of efflux pumps and their inhibitors. Essays Biochem 2017; 61:141-156. [PMID: 28258237 DOI: 10.1042/ebc20160065] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2016] [Revised: 12/13/2016] [Accepted: 12/19/2016] [Indexed: 11/17/2022]
Abstract
Antimicrobial resistance is based on the multifarious strategies that bacteria adopt to face antibiotic therapies, making it a key public health concern of our era. Among these strategies, efflux pumps (EPs) contribute significantly to increase the levels and profiles of resistance by expelling a broad range of unrelated compounds - buying time for the organisms to develop specific resistance. In Gram-negative bacteria, many of these chromosomally encoded transporters form multicomponent 'pumps' that span both inner and outer membranes and are driven energetically by a primary or secondary transporter component.One of the strategies to reinvigorate the efficacy of antimicrobials is by joint administration with EP inhibitors (EPI), which either block the substrate binding and/or hinder any of the transport-dependent steps of the pump. In this review, we provide an overview of multidrug-resistance EPs, their inhibition strategies and the relevant findings from the various computational simulation studies reported to date with respect to deciphering the mechanism of action of inhibitors with the purpose of improving their rational design.
Collapse
|
100
|
Mechanisms of envelope permeability and antibiotic influx and efflux in Gram-negative bacteria. Nat Microbiol 2017; 2:17001. [PMID: 28224989 DOI: 10.1038/nmicrobiol.2017.1] [Citation(s) in RCA: 187] [Impact Index Per Article: 26.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Accepted: 12/23/2016] [Indexed: 01/26/2023]
|