1
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Anlauf MT, Bilsing FL, Reiners J, Spitz O, Hachani E, Smits SHJ, Schmitt L. Type 1 secretion necessitates a tight interplay between all domains of the ABC transporter. Sci Rep 2024; 14:8994. [PMID: 38637678 PMCID: PMC11026475 DOI: 10.1038/s41598-024-59759-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Accepted: 04/15/2024] [Indexed: 04/20/2024] Open
Abstract
Type I secretion systems (T1SS) facilitate the secretion of substrates in one step across both membranes of Gram-negative bacteria. A prime example is the hemolysin T1SS which secretes the toxin HlyA. Secretion is energized by the ABC transporter HlyB, which forms a complex together with the membrane fusion protein HlyD and the outer membrane protein TolC. HlyB features three domains: an N-terminal C39 peptidase-like domain (CLD), a transmembrane domain (TMD) and a C-terminal nucleotide binding domain (NBD). Here, we created chimeric transporters by swapping one or more domains of HlyB with the respective domain(s) of RtxB, a HlyB homolog from Kingella kingae. We tested all chimeric transporters for their ability to secrete pro-HlyA when co-expressed with HlyD. The CLD proved to be most critical, as a substitution abolished secretion. Swapping only the TMD or NBD reduced the secretion efficiency, while a simultaneous exchange abolished secretion. These results indicate that the CLD is the most critical secretion determinant, while TMD and NBD might possess additional recognition or interaction sites. This mode of recognition represents a hierarchical and extreme unusual case of substrate recognition for ABC transporters and optimal secretion requires a tight interplay between all domains.
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Affiliation(s)
- Manuel T Anlauf
- Institute of Biochemistry, Heinrich Heine University Düsseldorf, Universitätsstraße 1, 40225, Düsseldorf, Germany
| | - Florestan L Bilsing
- Institute of Biochemistry, Heinrich Heine University Düsseldorf, Universitätsstraße 1, 40225, Düsseldorf, Germany
| | - Jens Reiners
- Center for Structural Studies, Heinrich Heine University Düsseldorf, Universitätsstraße 1, 40225, Düsseldorf, Germany
| | - Olivia Spitz
- Institute of Biochemistry, Heinrich Heine University Düsseldorf, Universitätsstraße 1, 40225, Düsseldorf, Germany
- INCONSULT, Duisburg, Germany
| | - Eymen Hachani
- Institute of Biochemistry, Heinrich Heine University Düsseldorf, Universitätsstraße 1, 40225, Düsseldorf, Germany
| | - Sander H J Smits
- Institute of Biochemistry, Heinrich Heine University Düsseldorf, Universitätsstraße 1, 40225, Düsseldorf, Germany
- Center for Structural Studies, Heinrich Heine University Düsseldorf, Universitätsstraße 1, 40225, Düsseldorf, Germany
| | - Lutz Schmitt
- Institute of Biochemistry, Heinrich Heine University Düsseldorf, Universitätsstraße 1, 40225, Düsseldorf, Germany.
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2
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The hemolysin A secretion system is a multi-engine pump containing three ABC transporters. Cell 2022; 185:3329-3340.e13. [DOI: 10.1016/j.cell.2022.07.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Revised: 06/20/2022] [Accepted: 07/18/2022] [Indexed: 11/17/2022]
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3
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Ford RC, Hellmich UA. What monomeric nucleotide binding domains can teach us about dimeric ABC proteins. FEBS Lett 2020; 594:3857-3875. [PMID: 32880928 DOI: 10.1002/1873-3468.13921] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 08/06/2020] [Accepted: 08/24/2020] [Indexed: 12/12/2022]
Abstract
The classic conceptualization of ATP binding cassette (ABC) transporter function is an ATP-dependent conformational change coupled to transport of a substrate across a biological membrane via the transmembrane domains (TMDs). The binding of two ATP molecules within the transporter's two nucleotide binding domains (NBDs) induces their dimerization. Despite retaining the ability to bind nucleotides, isolated NBDs frequently fail to dimerize. ABC proteins without a TMD, for example ABCE and ABCF, have NBDs tethered via elaborate linkers, further supporting that NBD dimerization does not readily occur for isolated NBDs. Intriguingly, even in full-length transporters, the NBD-dimerized, outward-facing state is not as frequently observed as might be expected. This leads to questions regarding what drives NBD interaction and the role of the TMDs or linkers. Understanding the NBD-nucleotide interaction and the subsequent NBD dimerization is thus pivotal for understanding ABC transporter activity in general. Here, we hope to provide new insights into ABC protein function by discussing the perplexing issue of (missing) NBD dimerization in isolation and in the context of full-length ABC proteins.
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Affiliation(s)
- Robert C Ford
- Faculty of Biology Medicine and Health, The University of Manchester, UK
| | - Ute A Hellmich
- Department of Chemistry, Johannes Gutenberg-University, Mainz, Germany.,Centre for Biomolecular Magnetic Resonance (BMRZ), Goethe-University, Frankfurt, Germany
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4
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Characterization of the nucleotide-binding domain NsrF from the BceAB-type ABC-transporter NsrFP from the human pathogen Streptococcus agalactiae. Sci Rep 2020; 10:15208. [PMID: 32938989 PMCID: PMC7494861 DOI: 10.1038/s41598-020-72237-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2020] [Accepted: 08/27/2020] [Indexed: 01/14/2023] Open
Abstract
Treatment of bacterial infections is a great challenge of our era due to the various resistance mechanisms against antibiotics. Antimicrobial peptides are considered to be potential novel compound as antibiotic treatment. However, some bacteria, especially many human pathogens, are inherently resistant to these compounds, due to the expression of BceAB-type ABC transporters. This rather new transporter family is not very well studied. Here, we report the first full characterization of the nucleotide binding domain of a BceAB type transporter from Streptococcus agalactiae, namely SaNsrF of the transporter SaNsrFP, which confers resistance against nisin and gallidermin. We determined the NTP hydrolysis kinetics and used molecular modeling and simulations in combination with small angle X-ray scattering to obtain structural models of the SaNsrF monomer and dimer. The fact that the SaNsrFH202A variant displayed no ATPase activity was rationalized in terms of changes of the structural dynamics of the dimeric interface. Kinetic data show a clear preference for ATP as a substrate, and the prediction of binding modes allowed us to explain this selectivity over other NTPs.
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5
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Lagedroste M, Reiners J, Smits SHJ, Schmitt L. Impact of the nisin modification machinery on the transport kinetics of NisT. Sci Rep 2020; 10:12295. [PMID: 32703992 PMCID: PMC7378552 DOI: 10.1038/s41598-020-69225-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Accepted: 07/06/2020] [Indexed: 01/24/2023] Open
Abstract
Lanthipeptides are ribosomally synthesized and post-translationally modified peptides containing dehydrated amino acids and (methyl-)lanthionine rings. One of the best-studied examples is nisin produced by Lactococcus lactis. Nisin is synthesized as a precursor peptide comprising of an N-terminal leader peptide and a C-terminal core peptide. Amongst others, the leader peptide is crucial for enzyme recognition and acts as a secretion signal for the ABC transporter NisT that secretes nisin in a proposed channeling mechanism. Here, we present an in vivo secretion analysis of this process in the presence and absence of the nisin maturation machinery, consisting of the dehydratase NisB and the cyclase NisC. Our determined apparent secretion rates of NisT show how NisB and NisC modulate the transport kinetics of NisA. Additional in vitro studies of the detergent-solubilized NisT revealed how these enzymes and the substrates again influence the activity of transporter. In summary, this study highlights the pivotal role of NisB for NisT in the secretion process.
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Affiliation(s)
- Marcel Lagedroste
- Institute of Biochemistry, Heinrich Heine University Düsseldorf, Universitätsstr. 1, 40225, Düsseldorf, Germany
| | - Jens Reiners
- Institute of Biochemistry, Heinrich Heine University Düsseldorf, Universitätsstr. 1, 40225, Düsseldorf, Germany.,Center for Structural Studies, Heinrich Heine University Düsseldorf, Universitätsstr. 1, 40225, Düsseldorf, Germany
| | - Sander H J Smits
- Institute of Biochemistry, Heinrich Heine University Düsseldorf, Universitätsstr. 1, 40225, Düsseldorf, Germany
| | - Lutz Schmitt
- Institute of Biochemistry, Heinrich Heine University Düsseldorf, Universitätsstr. 1, 40225, Düsseldorf, Germany.
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6
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Biochemical and structural characterization of murine GBP7, a guanylate binding protein with an elongated C-terminal tail. Biochem J 2020; 476:3161-3182. [PMID: 31689351 DOI: 10.1042/bcj20190364] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 10/08/2019] [Accepted: 10/09/2019] [Indexed: 12/23/2022]
Abstract
Guanylate-binding proteins (GBPs) constitute a family of interferon-inducible guanosine triphosphatases (GTPases) that are key players in host defense against intracellular pathogens ranging from protozoa to bacteria and viruses. So far, human GBP1 and GBP5 as well as murine GBP2 (mGBP2) have been biochemically characterized in detail. Here, with murine GBP7 (mGBP7), a GBP family member with an unconventional and elongated C-terminus is analyzed. The present study demonstrates that mGBP7 exhibits a concentration-dependent GTPase activity and an apparent GTP turnover number of 20 min-1. In addition, fluorescence spectroscopy analyses reveal that mGBP7 binds GTP with high affinity (KD = 0.22 µM) and GTPase activity assays indicate that mGBP7 hydrolyzes GTP to GDP and GMP. The mGBP7 GTPase activity is inhibited by incubation with γ-phosphate analogs and a K51A mutation interfering with GTP binding. SEC-MALS analyses give evidence that mGBP7 forms transient dimers and that this oligomerization pattern is not influenced by the presence of nucleotides. Moreover, a structural model for mGBP7 is provided by homology modeling, which shows that the GTPase possesses an elongated C-terminal (CT) tail compared with the CaaX motif-containing mGBP2 and human GBP1. Molecular dynamics simulations indicate that this tail has transmembrane characteristics and, interestingly, confocal microscopy analyses reveal that the CT tail is required for recruitment of mGBP7 to the parasitophorous vacuole of Toxoplasma gondii.
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7
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Kanonenberg K, Royes J, Kedrov A, Poschmann G, Angius F, Solgadi A, Spitz O, Kleinschrodt D, Stühler K, Miroux B, Schmitt L. Shaping the lipid composition of bacterial membranes for membrane protein production. Microb Cell Fact 2019; 18:131. [PMID: 31400768 PMCID: PMC6689329 DOI: 10.1186/s12934-019-1182-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Accepted: 07/30/2019] [Indexed: 12/29/2022] Open
Abstract
Background The overexpression and purification of membrane proteins is a bottleneck in biotechnology and structural biology. E. coli remains the host of choice for membrane protein production. To date, most of the efforts have focused on genetically tuning of expression systems and shaping membrane composition to improve membrane protein production remained largely unexplored. Results In E. coli C41(DE3) strain, we deleted two transporters involved in fatty acid metabolism (OmpF and AcrB), which are also recalcitrant contaminants crystallizing even at low concentration. Engineered expression hosts presented an enhanced fitness and improved folding of target membrane proteins, which correlated with an altered membrane fluidity. We demonstrated the scope of this approach by overproducing several membrane proteins (4 different ABC transporters, YidC and SecYEG). Conclusions In summary, E. coli membrane engineering unprecedentedly increases the quality and yield of membrane protein preparations. This strategy opens a new field for membrane protein production, complementary to gene expression tuning. Electronic supplementary material The online version of this article (10.1186/s12934-019-1182-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Kerstin Kanonenberg
- Institute of Biochemistry, Heinrich-Heine-University Duesseldorf, Universitaetsstr. 1, 40225, Duesseldorf, Germany.,CNRS, UMR5086 "Molecular Microbiology and Structural Biochemistry", Université de Lyon, 7 Passage du vercors, 69007, Lyon, France
| | - Jorge Royes
- Laboratoire de Biologie Physico-Chimique des Protéines Membranaires, UMR7099, CNRS, IBPC, Université Paris Diderot, Sorbonne Paris Cité, 13 rue Pierre et Marie Curie, 75005, Paris, France
| | - Alexej Kedrov
- Institute of Biochemistry, Heinrich-Heine-University Duesseldorf, Universitaetsstr. 1, 40225, Duesseldorf, Germany
| | - Gereon Poschmann
- Molecular Proteomics Laboratory, Biologisch Medizinisches Forschungszentrum (BMFZ), Heinrich-Heine-University Duesseldorf, Duesseldorf, Germany
| | - Federica Angius
- Laboratoire de Biologie Physico-Chimique des Protéines Membranaires, UMR7099, CNRS, IBPC, Université Paris Diderot, Sorbonne Paris Cité, 13 rue Pierre et Marie Curie, 75005, Paris, France.,Department of Microbiology, Institute for Water and Wetland Research, Heyendaalseweg 135, 6525, Nijmegen, The Netherlands
| | - Audrey Solgadi
- Institut Paris Saclay d'Innovation Thérapeutique, INSERM, CNRS, - Plateforme SAMM, Université Paris-Saclay, Châtenay-Malabry, France
| | - Olivia Spitz
- Institute of Biochemistry, Heinrich-Heine-University Duesseldorf, Universitaetsstr. 1, 40225, Duesseldorf, Germany
| | - Diana Kleinschrodt
- Institute of Biochemistry, Heinrich-Heine-University Duesseldorf, Universitaetsstr. 1, 40225, Duesseldorf, Germany
| | - Kai Stühler
- Molecular Proteomics Laboratory, Biologisch Medizinisches Forschungszentrum (BMFZ), Heinrich-Heine-University Duesseldorf, Duesseldorf, Germany
| | - Bruno Miroux
- Laboratoire de Biologie Physico-Chimique des Protéines Membranaires, UMR7099, CNRS, IBPC, Université Paris Diderot, Sorbonne Paris Cité, 13 rue Pierre et Marie Curie, 75005, Paris, France.
| | - Lutz Schmitt
- Institute of Biochemistry, Heinrich-Heine-University Duesseldorf, Universitaetsstr. 1, 40225, Duesseldorf, Germany.
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8
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Functional Reconstitution of HlyB, a Type I Secretion ABC Transporter, in Saposin-A Nanoparticles. Sci Rep 2019; 9:8436. [PMID: 31182729 PMCID: PMC6558041 DOI: 10.1038/s41598-019-44812-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2018] [Accepted: 05/23/2019] [Indexed: 11/08/2022] Open
Abstract
Type I secretion systems (T1SS) are ubiquitous transport machineries in Gram-negative bacteria. They comprise a relatively simple assembly of three membrane-localised proteins: an inner-membrane complex composed of an ABC transporter and a membrane fusion protein, and a TolC-like outer membrane component. T1SS transport a wide variety of substrates with broad functional diversity. The ABC transporter hemolysin B (HlyB), for example, is part of the hemolysin A-T1SS in Escherichia coli. In contrast to canonical ABC transporters, an accessory domain, a C39 peptidase-like domain (CLD), is located at the N-terminus of HlyB and is essential for secretion. In this study, we have established an optimised purification protocol for HlyB and the subsequent reconstitution employing the saposin-nanoparticle system. We point out the negative influence of free detergent on the basal ATPase activity of HlyB, studied the influence of a lysolipid or lipid matrix on activity and present functional studies with the full-length substrate proHlyA in its folded and unfolded states, which both have a stimulatory effect on the ATPase activity.
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9
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Richard KL, Kelley BR, Johnson JG. Heme Uptake and Utilization by Gram-Negative Bacterial Pathogens. Front Cell Infect Microbiol 2019; 9:81. [PMID: 30984629 PMCID: PMC6449446 DOI: 10.3389/fcimb.2019.00081] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 03/08/2019] [Indexed: 02/06/2023] Open
Abstract
Iron is a transition metal utilized by nearly all forms of life for essential cellular processes, such as DNA synthesis and cellular respiration. During infection by bacterial pathogens, the host utilizes various strategies to sequester iron in a process termed, nutritional immunity. To circumvent these defenses, Gram-negative pathogens have evolved numerous mechanisms to obtain iron from heme. In this review we outline the systems that exist in several Gram-negative pathogens that are associated with heme transport and utilization, beginning with hemolysis and concluding with heme degradation. In addition, Gram-negative pathogens must also closely regulate the intracellular concentrations of iron and heme, since high levels of iron can lead to the generation of toxic reactive oxygen species. As such, we also provide several examples of regulatory pathways that control heme utilization, showing that co-regulation with other cellular processes is complex and often not completely understood.
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Affiliation(s)
- Kaylie L Richard
- Department of Microbiology, University of Tennessee, Knoxville, TN, United States
| | - Brittni R Kelley
- Department of Microbiology, University of Tennessee, Knoxville, TN, United States
| | - Jeremiah G Johnson
- Department of Microbiology, University of Tennessee, Knoxville, TN, United States
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10
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Neuberger A, Du D, Luisi BF. Structure and mechanism of bacterial tripartite efflux pumps. Res Microbiol 2018; 169:401-413. [PMID: 29787834 DOI: 10.1016/j.resmic.2018.05.003] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2017] [Revised: 02/20/2018] [Accepted: 05/14/2018] [Indexed: 12/22/2022]
Abstract
Efflux pumps are membrane proteins which contribute to multi-drug resistance. In Gram-negative bacteria, some of these pumps form complex tripartite assemblies in association with an outer membrane channel and a periplasmic membrane fusion protein. These tripartite machineries span both membranes and the periplasmic space, and they extrude from the bacterium chemically diverse toxic substrates. In this chapter, we summarise current understanding of the structural architecture, functionality, and regulation of tripartite multi-drug efflux assemblies.
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Affiliation(s)
- Arthur Neuberger
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1GA, UK
| | - Dijun Du
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1GA, UK
| | - Ben F Luisi
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1GA, UK.
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11
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Kanonenberg K, Spitz O, Erenburg IN, Beer T, Schmitt L. Type I secretion system—it takes three and a substrate. FEMS Microbiol Lett 2018; 365:4966979. [DOI: 10.1093/femsle/fny094] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Accepted: 04/09/2018] [Indexed: 12/20/2022] Open
Affiliation(s)
- Kerstin Kanonenberg
- Institute of Biochemistry, Heinrich Heine University, 40225 Düsseldorf, Germany
| | - Olivia Spitz
- Institute of Biochemistry, Heinrich Heine University, 40225 Düsseldorf, Germany
| | - Isabelle N Erenburg
- Institute of Biochemistry, Heinrich Heine University, 40225 Düsseldorf, Germany
| | - Tobias Beer
- Institute of Biochemistry, Heinrich Heine University, 40225 Düsseldorf, Germany
| | - Lutz Schmitt
- Institute of Biochemistry, Heinrich Heine University, 40225 Düsseldorf, Germany
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12
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ATPase activity regulation by leader peptide processing of ABC transporter maturation and secretion protein, NukT, for lantibiotic nukacin ISK-1. Appl Microbiol Biotechnol 2017; 102:763-772. [DOI: 10.1007/s00253-017-8645-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Revised: 11/09/2017] [Accepted: 11/12/2017] [Indexed: 10/18/2022]
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13
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Structure of a Type-1 Secretion System ABC Transporter. Structure 2017; 25:522-529. [PMID: 28216041 DOI: 10.1016/j.str.2017.01.010] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Revised: 12/13/2016] [Accepted: 01/29/2017] [Indexed: 02/07/2023]
Abstract
Type-1 secretion systems (T1SSs) represent a widespread mode of protein secretion across the cell envelope in Gram-negative bacteria. The T1SS is composed of an inner-membrane ABC transporter, a periplasmic membrane-fusion protein, and an outer-membrane porin. These three components assemble into a complex spanning both membranes and providing a conduit for the translocation of unfolded polypeptides. We show that ATP hydrolysis and assembly of the entire T1SS complex is necessary for protein secretion. Furthermore, we present a 3.15-Å crystal structure of AaPrtD, the ABC transporter found in the Aquifex aeolicus T1SS. The structure suggests a substrate entry window just above the transporter's nucleotide binding domains. In addition, highly kinked transmembrane helices, which frame a narrow channel not observed in canonical peptide transporters, are likely involved in substrate translocation. Overall, the AaPrtD structure supports a polypeptide transport mechanism distinct from alternating access.
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14
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Lenders MHH, Beer T, Smits SHJ, Schmitt L. In vivo quantification of the secretion rates of the hemolysin A Type I secretion system. Sci Rep 2016; 6:33275. [PMID: 27616645 PMCID: PMC5018854 DOI: 10.1038/srep33275] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Accepted: 08/24/2016] [Indexed: 01/08/2023] Open
Abstract
Type 1 secretion systems (T1SS) of Gram-negative bacteria secrete a broad range of substrates into the extracellular space. Common to all substrates is a C-terminal secretion sequence and nonapeptide repeats in the C-terminal part that bind Ca2+ in the extracellular space, to trigger protein folding. Like all T1SS, the hemolysin A (HlyA) T1SS of Escherichia coli consists of an ABC transporter, a membrane fusion protein and an outer membrane protein allowing the one step translocation of the substrate across both membranes. Here, we analyzed the secretion rate of the HlyA T1SS. Our results demonstrate that the rate is independent of substrate-size and operates at a speed of approximately 16 amino acids per transporter per second. We also demonstrate that the rate is independent of the extracellular Ca2+ concentration raising the question of the driving force of substrate secretion by T1SS in general.
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Affiliation(s)
- Michael H H Lenders
- Institute of Biochemistry, Heinrich-Heine-Universitaet, 40225 Duesseldorf, Germany
| | - Tobias Beer
- Institute of Biochemistry, Heinrich-Heine-Universitaet, 40225 Duesseldorf, Germany
| | - Sander H J Smits
- Institute of Biochemistry, Heinrich-Heine-Universitaet, 40225 Duesseldorf, Germany
| | - Lutz Schmitt
- Institute of Biochemistry, Heinrich-Heine-Universitaet, 40225 Duesseldorf, Germany
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