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Alav I, Kobylka J, Kuth MS, Pos KM, Picard M, Blair JMA, Bavro VN. Structure, Assembly, and Function of Tripartite Efflux and Type 1 Secretion Systems in Gram-Negative Bacteria. Chem Rev 2021; 121:5479-5596. [PMID: 33909410 PMCID: PMC8277102 DOI: 10.1021/acs.chemrev.1c00055] [Citation(s) in RCA: 99] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Indexed: 12/11/2022]
Abstract
Tripartite efflux pumps and the related type 1 secretion systems (T1SSs) in Gram-negative organisms are diverse in function, energization, and structural organization. They form continuous conduits spanning both the inner and the outer membrane and are composed of three principal components-the energized inner membrane transporters (belonging to ABC, RND, and MFS families), the outer membrane factor channel-like proteins, and linking the two, the periplasmic adaptor proteins (PAPs), also known as the membrane fusion proteins (MFPs). In this review we summarize the recent advances in understanding of structural biology, function, and regulation of these systems, highlighting the previously undescribed role of PAPs in providing a common architectural scaffold across diverse families of transporters. Despite being built from a limited number of basic structural domains, these complexes present a staggering variety of architectures. While key insights have been derived from the RND transporter systems, a closer inspection of the operation and structural organization of different tripartite systems reveals unexpected analogies between them, including those formed around MFS- and ATP-driven transporters, suggesting that they operate around basic common principles. Based on that we are proposing a new integrated model of PAP-mediated communication within the conformational cycling of tripartite systems, which could be expanded to other types of assemblies.
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Affiliation(s)
- Ilyas Alav
- Institute
of Microbiology and Infection, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
| | - Jessica Kobylka
- Institute
of Biochemistry, Biocenter, Goethe Universität
Frankfurt, Max-von-Laue-Straße 9, D-60438 Frankfurt, Germany
| | - Miriam S. Kuth
- Institute
of Biochemistry, Biocenter, Goethe Universität
Frankfurt, Max-von-Laue-Straße 9, D-60438 Frankfurt, Germany
| | - Klaas M. Pos
- Institute
of Biochemistry, Biocenter, Goethe Universität
Frankfurt, Max-von-Laue-Straße 9, D-60438 Frankfurt, Germany
| | - Martin Picard
- Laboratoire
de Biologie Physico-Chimique des Protéines Membranaires, CNRS
UMR 7099, Université de Paris, 75005 Paris, France
- Fondation
Edmond de Rothschild pour le développement de la recherche
Scientifique, Institut de Biologie Physico-Chimique, 75005 Paris, France
| | - Jessica M. A. Blair
- Institute
of Microbiology and Infection, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
| | - Vassiliy N. Bavro
- School
of Life Sciences, University of Essex, Colchester, CO4 3SQ United Kingdom
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Shvarev D, Maldener I. The HlyD-like membrane fusion protein All5304 is essential for acid stress survival of the filamentous cyanobacterium Anabaena sp. PCC 7120. FEMS Microbiol Lett 2020; 367:5863934. [PMID: 32592389 DOI: 10.1093/femsle/fnaa108] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Accepted: 06/25/2020] [Indexed: 12/23/2022] Open
Abstract
Acid stress is an environmental problem for plants and fresh water cyanobacteria like the filamentous, heterocyst forming species Anabaena sp. PCC 7120 (hereafter Anabaena sp.). Heterocyst differentiation, cell-cell communication and nitrogen fixation has been deeply studied in this model organism, but little is known about the cellular response of Anabaena sp. to decreased pH values, causing acid stress. ATP-binding cassette (ABC) transporters are involved in acid stress response in other bacteria, by exporting proteins responsible for survival under acidification. The genome of Anabaena sp. encodes numerous ABC transporter components, whose function is not known yet. Here, we describe the function of the gene all5304 encoding a protein with homology to membrane fusion proteins of tripartite efflux pumps driven by ABC transporters like HlyBD-TolC of Escherichia coli. The all5304 mutant shows less resistance against low pH, even though the expression of the gene is independent from the pH of the medium. We compared the exoproteome of the wild type and mutant cultures and identified three proteins-candidate substrates of the putative transporter. Including the in silico analysis of All5304, our results suggest that All5304 functions as part of an efflux pump, secreting of a protein necessary for acid tolerance in Anabaena sp.
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Affiliation(s)
- Dmitry Shvarev
- Organismic Interactions, Interfaculty Institute of Microbiology and Infection Medicine, Eberhard Karls University of Tübingen, Auf der Morgenstelle 28, 72076 Tübingen, Germany
| | - Iris Maldener
- Organismic Interactions, Interfaculty Institute of Microbiology and Infection Medicine, Eberhard Karls University of Tübingen, Auf der Morgenstelle 28, 72076 Tübingen, Germany
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Shvarev D, Maldener I. ATP-binding cassette transporters of the multicellular cyanobacterium Anabaena sp. PCC 7120: a wide variety for a complex lifestyle. FEMS Microbiol Lett 2019; 365:4817535. [PMID: 29360977 DOI: 10.1093/femsle/fny012] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Accepted: 01/18/2018] [Indexed: 01/29/2023] Open
Abstract
Two hundred genes or 3% of the known or putative protein-coding genes of the filamentous freshwater cyanobacterium Anabaena sp. PCC 7120 encode domains of ATP-binding cassette (ABC) transporters. Detailed characterization of some of these transporters (14-15 importers and 5 exporters) has revealed their crucial roles in the complex lifestyle of this multicellular photoautotroph, which is able to differentiate specialized cells for nitrogen fixation. This review summarizes the characteristics of the ABC transporters of Anabaena sp. PCC 7120 known to date.
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Affiliation(s)
- Dmitry Shvarev
- Organismic Interactions, Interfaculty Institute of Microbiology and Infection Medicine, University of Tübingen, Auf der Morgenstelle 28, 72076 Tübingen, Germany
| | - Iris Maldener
- Organismic Interactions, Interfaculty Institute of Microbiology and Infection Medicine, University of Tübingen, Auf der Morgenstelle 28, 72076 Tübingen, Germany
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Roles of DevBCA-like ABC transporters in the physiology of Anabaena sp. PCC 7120. Int J Med Microbiol 2019; 309:325-330. [DOI: 10.1016/j.ijmm.2019.04.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 04/10/2019] [Accepted: 04/26/2019] [Indexed: 01/19/2023] Open
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Shvarev D, Nishi CN, Maldener I. Two DevBCA‐like ABC transporters are involved in the multidrug resistance of the cyanobacterium
Anabaena
sp. PCC 7120. FEBS Lett 2019; 593:1818-1826. [DOI: 10.1002/1873-3468.13450] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 05/07/2019] [Accepted: 05/14/2019] [Indexed: 11/10/2022]
Affiliation(s)
- Dmitry Shvarev
- Organismic Interactions Interfaculty Institute of Microbiology and Infection Medicine Eberhard Karls University of Tübingen Germany
| | - Carolina N. Nishi
- Organismic Interactions Interfaculty Institute of Microbiology and Infection Medicine Eberhard Karls University of Tübingen Germany
| | - Iris Maldener
- Organismic Interactions Interfaculty Institute of Microbiology and Infection Medicine Eberhard Karls University of Tübingen Germany
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Shvarev D, Nishi CN, Maldener I. Glycolipid composition of the heterocyst envelope of Anabaena sp. PCC 7120 is crucial for diazotrophic growth and relies on the UDP-galactose 4-epimerase HgdA. Microbiologyopen 2019; 8:e00811. [PMID: 30803160 PMCID: PMC6692557 DOI: 10.1002/mbo3.811] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 01/10/2019] [Accepted: 01/14/2019] [Indexed: 01/05/2023] Open
Abstract
The nitrogenase complex in the heterocysts of the filamentous freshwater cyanobacterium Anabaenasp. PCC 7120 fixes atmospheric nitrogen to allow diazotrophic growth. The heterocyst cell envelope protects the nitrogenase from oxygen and consists of a polysaccharide and a glycolipid layer that are formed by a complex process involving the recruitment of different proteins. Here, we studied the function of the putative nucleoside‐diphosphate‐sugar epimerase HgdA, which along with HgdB and HgdC is essential for deposition of the glycolipid layer and growth without a combined nitrogen source. Using site‐directed mutagenesis and single homologous recombination approach, we performed a thoroughly functional characterization of HgdA and confirmed that the glycolipid layer of the hgdAmutant heterocyst is aberrant as shown by transmission electron microscopy and chemical analysis. The hgdA gene was expressed during late stages of the heterocyst differentiation. GFP‐tagged HgdA protein localized inside the heterocysts. The purified HgdA protein had UDP‐galactose 4‐epimerase activity in vitro. This enzyme could be responsible for synthesis of heterocyst‐specific glycolipid precursors, which could be transported over the cell wall by the ABC transporter components HgdB/HgdC.
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Affiliation(s)
- Dmitry Shvarev
- Organismic Interactions, Interfaculty Institute of Microbiology and Infection Medicine, Eberhard Karls University of Tübingen, Tübingen, Germany
| | - Carolina N Nishi
- Organismic Interactions, Interfaculty Institute of Microbiology and Infection Medicine, Eberhard Karls University of Tübingen, Tübingen, Germany
| | - Iris Maldener
- Organismic Interactions, Interfaculty Institute of Microbiology and Infection Medicine, Eberhard Karls University of Tübingen, Tübingen, Germany
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The ABC Transporter Components HgdB and HgdC are Important for Glycolipid Layer Composition and Function of Heterocysts in Anabaena sp. PCC 7120. Life (Basel) 2018; 8:life8030026. [PMID: 30004454 PMCID: PMC6161253 DOI: 10.3390/life8030026] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Revised: 06/21/2018] [Accepted: 06/28/2018] [Indexed: 12/13/2022] Open
Abstract
Anabaena sp. PCC 7120 is a filamentous cyanobacterium able to fix atmospheric nitrogen in semi-regularly spaced heterocysts. For correct heterocyst function, a special cell envelope consisting of a glycolipid layer and a polysaccharide layer is essential. We investigated the role of the genes hgdB and hgdC, encoding domains of a putative ABC transporter, in heterocyst maturation. We investigated the subcellular localization of the fusion protein HgdC-GFP and followed the differential expression of the hgdB and hgdC genes during heterocyst maturation. Using a single recombination approach, we created a mutant in hgdB gene and studied its phenotype by microscopy and analytical chromatography. Although heterocysts are formed in the mutant, the structure of the glycolipid layer is aberrant and also contains an atypical ratio of the two major glycolipids. As shown by a pull-down assay, HgdB interacts with the outer membrane protein TolC, which indicates a function as a type 1 secretion system. We show that the hgdB-hgdC genes are essential for the creation of micro-oxic conditions by influencing the correct composition of the glycolipid layer for heterocyst function. Our observations confirm the significance of the hgdB-hgdC gene cluster and shed light on a novel mode of regulation of heterocyst envelope formation.
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Chrismas NAM, Barker G, Anesio AM, Sánchez-Baracaldo P. Genomic mechanisms for cold tolerance and production of exopolysaccharides in the Arctic cyanobacterium Phormidesmis priestleyi BC1401. BMC Genomics 2016; 17:533. [PMID: 27485510 PMCID: PMC4971617 DOI: 10.1186/s12864-016-2846-4] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Accepted: 06/20/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Cyanobacteria are major primary producers in extreme cold ecosystems. Many lineages of cyanobacteria thrive in these harsh environments, but it is not fully understood how they survive in these conditions and whether they have evolved specific mechanisms of cold adaptation. Phormidesmis priestleyi is a cyanobacterium found throughout the cold biosphere (Arctic, Antarctic and alpine habitats). Genome sequencing of P. priestleyi BC1401, an isolate from a cryoconite hole on the Greenland Ice Sheet, has allowed for the examination of genes involved in cold shock response and production of extracellular polymeric substances (EPS). EPSs likely enable cyanobacteria to buffer the effects of extreme cold and by identifying mechanisms for EPS production in P. priestleyi BC1401 this study lays the way for investigating transcription and regulation of EPS production in an ecologically important cold tolerant cyanobacterium. RESULTS We sequenced the draft genome of P. priestleyi BC1401 and implemented a new de Bruijn graph visualisation approach combined with BLAST analysis to separate cyanobacterial contigs from a simple metagenome generated from non-axenic cultures. Comparison of known cold adaptation genes in P. priestleyi BC1401 with three relatives from other environments revealed no clear differences between lineages. Genes involved in EPS biosynthesis were identified from the Wzy- and ABC-dependent pathways. The numbers of genes involved in cell wall and membrane biogenesis in P. priestleyi BC1401 were typical relative to the genome size. A gene cluster implicated in biofilm formation was found homologous to the Wps system, although the intracellular signalling pathways by which this could be regulated remain unclear. CONCLUSIONS Results show that the genomic characteristics and complement of known cold shock genes in P. priestleyi BC1401 are comparable to related lineages from a wide variety of habitats, although as yet uncharacterised cold shock genes in this organism may still exist. EPS production by P. priestleyi BC1401 likely contributes to its ability to survive efficiently in cold environments, yet this mechanism is widely distributed throughout the cyanobacterial phylum. Discovering how these EPS related mechanisms are regulated may help explain why P. priestleyi BC1401 is so successful in cold environments where related lineages are not.
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Affiliation(s)
- Nathan A M Chrismas
- Bristol Glaciology Centre, School of Geographical Sciences, University of Bristol, Bristol, BS8 1SS, UK.
| | - Gary Barker
- Cereal Genomics, School of Biological Sciences, University of Bristol, Bristol, BS8 1SS, UK
| | - Alexandre M Anesio
- Bristol Glaciology Centre, School of Geographical Sciences, University of Bristol, Bristol, BS8 1SS, UK
| | - Patricia Sánchez-Baracaldo
- Bristol Glaciology Centre, School of Geographical Sciences, University of Bristol, Bristol, BS8 1SS, UK.
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D'Agostino PM, Song X, Neilan BA, Moffitt MC. Comparative proteomics reveals that a saxitoxin-producing and a nontoxic strain of Anabaena circinalis are two different ecotypes. J Proteome Res 2014; 13:1474-84. [PMID: 24460188 DOI: 10.1021/pr401007k] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
In Australia, saxitoxin production is restricted to the cyanobacterial species Anabaena circinalis and is strain-dependent. We aimed to characterize a saxitoxin-producing and nontoxic strain of A. circinalis at the proteomic level using iTRAQ. Seven proteins putatively involved in saxitoxin biosynthesis were identified within our iTRAQ experiment for the first time. The proteomic profile of the toxic A. circinalis was significantly different from the nontoxic strain, indicating that each is likely to inhabit a unique ecological niche. Under control growth conditions, the saxitoxin-producing A. circinalis displayed a higher abundance of photosynthetic, carbon fixation and nitrogen metabolic proteins. Differential abundance of these proteins suggests a higher intracellular C:N ratio and a higher concentration of intracellular 2-oxoglutarate in our toxic strain compared with the nontoxic strain. This may be a novel site for posttranslational regulation because saxitoxin biosynthesis putatively requires a 2-oxoglutarate-dependent dioxygenase. The nontoxic A. circinalis was more abundant in proteins, indicating cellular stress. Overall, our study has provided the first insight into fundamental differences between a toxic and nontoxic strain of A. circinalis, indicating that they are distinct ecotypes.
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Affiliation(s)
- Paul M D'Agostino
- School of Science and Health, University of Western Sydney , Campbelltown, NSW 2560, Australia
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Staron P, Forchhammer K, Maldener I. Structure-function analysis of the ATP-driven glycolipid efflux pump DevBCA reveals complex organization with TolC/HgdD. FEBS Lett 2013; 588:395-400. [PMID: 24361095 DOI: 10.1016/j.febslet.2013.12.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2013] [Revised: 12/02/2013] [Accepted: 12/03/2013] [Indexed: 11/16/2022]
Abstract
In Gram-negative bacteria, trans-envelope efflux pumps have periplasmic membrane fusion proteins (MFPs) as essential components. MFPs act as mediators between outer membrane factors (OMFs) and inner membrane factors (IMFs). In this study, structure-function relations of the ATP-driven glycolipid efflux pump DevBCA-TolC/HgdD from the cyanobacterium Anabaena sp. PCC 7120 were analyzed. The binding of the MFP DevB to the OMF TolC absolutely required the respective tip-regions. The interaction of DevB with the IMF DevAC mainly involved the β-barrel and the lipoyl domain. Efficient binding to DevAC and TolC, substrate recognition and export activity by DevAC were dependent on stable DevB hexamers.
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Affiliation(s)
- Peter Staron
- Institute of Microbiology and Infection Medicine/Organismic Interactions, University of Tübingen, 72076 Tübingen, Germany
| | - Karl Forchhammer
- Institute of Microbiology and Infection Medicine/Organismic Interactions, University of Tübingen, 72076 Tübingen, Germany
| | - Iris Maldener
- Institute of Microbiology and Infection Medicine/Organismic Interactions, University of Tübingen, 72076 Tübingen, Germany.
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