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Thangaratnarajah C, Nijland M, Borges-Araújo L, Jeucken A, Rheinberger J, Marrink SJ, Souza PCT, Paulino C, Slotboom DJ. Expulsion mechanism of the substrate-translocating subunit in ECF transporters. Nat Commun 2023; 14:4484. [PMID: 37491368 PMCID: PMC10368641 DOI: 10.1038/s41467-023-40266-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Accepted: 07/20/2023] [Indexed: 07/27/2023] Open
Abstract
Energy-coupling factor (ECF)-type transporters mediate the uptake of micronutrients in many bacteria. They consist of a substrate-translocating subunit (S-component) and an ATP-hydrolysing motor (ECF module) Previous data indicate that the S-component topples within the membrane to alternately expose the binding site to either side of the membrane. In many ECF transporters, the substrate-free S-component can be expelled from the ECF module. Here we study this enigmatic expulsion step by cryogenic electron microscopy and reveal that ATP induces a concave-to-convex shape change of two long helices in the motor, thereby destroying the S-component's docking site and allowing for its dissociation. We show that adaptation of the membrane morphology to the conformational state of the motor may favour expulsion of the substrate-free S-component when ATP is bound and docking of the substrate-loaded S-component after hydrolysis. Our work provides a picture of bilayer-assisted chemo-mechanical coupling in the transport cycle of ECF transporters.
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Affiliation(s)
- Chancievan Thangaratnarajah
- Faculty of Science and Engineering, Groningen Biomolecular Sciences and Biotechnology, Membrane Enzymology Group, University of Groningen, 9747 AG, Groningen, The Netherlands
- Faculty of Science and Engineering, Groningen Biomolecular Sciences and Biotechnology, Electron Microscopy Group, University of Groningen, 9747 AG, Groningen, The Netherlands
| | - Mark Nijland
- Faculty of Science and Engineering, Groningen Biomolecular Sciences and Biotechnology, Membrane Enzymology Group, University of Groningen, 9747 AG, Groningen, The Netherlands
| | - Luís Borges-Araújo
- Molecular Microbiology and Structural Biochemistry, CNRS and University of Lyon, 69367, Lyon, France
| | - Aike Jeucken
- Faculty of Science and Engineering, Groningen Biomolecular Sciences and Biotechnology, Membrane Enzymology Group, University of Groningen, 9747 AG, Groningen, The Netherlands
| | - Jan Rheinberger
- Faculty of Science and Engineering, Groningen Biomolecular Sciences and Biotechnology, Membrane Enzymology Group, University of Groningen, 9747 AG, Groningen, The Netherlands
- Faculty of Science and Engineering, Groningen Biomolecular Sciences and Biotechnology, Electron Microscopy Group, University of Groningen, 9747 AG, Groningen, The Netherlands
- Biochemistry Center, University of Heidelberg, Im Neuenheimer Feld 328, 69120, Heidelberg, Germany
| | - Siewert J Marrink
- Faculty of Science and Engineering, Groningen Biomolecular Sciences and Biotechnology, Molecular Dynamics Group, University of Groningen, 9747 AG, Groningen, The Netherlands
| | - Paulo C T Souza
- Molecular Microbiology and Structural Biochemistry, CNRS and University of Lyon, 69367, Lyon, France
| | - Cristina Paulino
- Faculty of Science and Engineering, Groningen Biomolecular Sciences and Biotechnology, Membrane Enzymology Group, University of Groningen, 9747 AG, Groningen, The Netherlands.
- Faculty of Science and Engineering, Groningen Biomolecular Sciences and Biotechnology, Electron Microscopy Group, University of Groningen, 9747 AG, Groningen, The Netherlands.
- Biochemistry Center, University of Heidelberg, Im Neuenheimer Feld 328, 69120, Heidelberg, Germany.
| | - Dirk J Slotboom
- Faculty of Science and Engineering, Groningen Biomolecular Sciences and Biotechnology, Membrane Enzymology Group, University of Groningen, 9747 AG, Groningen, The Netherlands.
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2
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Younus I, Kochkina S, Choi CC, Sun W, Ford RC. ATP-Binding Cassette Transporters: Snap-on Complexes? Subcell Biochem 2022; 99:35-82. [PMID: 36151373 DOI: 10.1007/978-3-031-00793-4_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
ATP-binding cassette (ABC) transporters are one of the largest families of membrane proteins in prokaryotic organisms. Much is now understood about the structure of these transporters and many reviews have been written on that subject. In contrast, less has been written on the assembly of ABC transporter complexes and this will be a major focus of this book chapter. The complexes are formed from two cytoplasmic subunits that are highly conserved (in terms of their primary and three-dimensional structures) across the whole family. These ATP-binding subunits give rise to the name of the family. They must assemble with two transmembrane subunits that will typically form the permease component of the transporter. The transmembrane subunits have been found to be surprisingly diverse in structure when the whole family is examined, with seven distinct folds identified so far. Hence nucleotide-binding subunits appear to have been bolted on to a variety of transmembrane platforms during evolution, leading to a greater variety in function. Furthermore, many importers within the family utilise a further external substrate-binding component to trap scarce substrates and deliver them to the correct permease components. In this chapter, we will discuss whether assembly of the various ABC transporter subunits occurs with high fidelity within the crowded cellular environment and whether promiscuity in assembly of transmembrane and cytoplasmic components can occur. We also discuss the new AlphaFold protein structure prediction tool which predicts a new type of transmembrane domain fold within the ABC transporters that is associated with cation exporters of bacteria and plants.
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Affiliation(s)
- Iqra Younus
- Faculty of Biology, Medicine and Health, School of Biological Sciences, The University of Manchester, Manchester, UK
| | - Sofia Kochkina
- Faculty of Biology, Medicine and Health, School of Biological Sciences, The University of Manchester, Manchester, UK
| | - Cheri C Choi
- Faculty of Biology, Medicine and Health, School of Biological Sciences, The University of Manchester, Manchester, UK
| | - Wenjuan Sun
- Faculty of Biology, Medicine and Health, School of Biological Sciences, The University of Manchester, Manchester, UK
| | - Robert C Ford
- Faculty of Biology, Medicine and Health, School of Biological Sciences, The University of Manchester, Manchester, UK.
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3
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Abstract
Membrane proteins (MPs) play essential roles in numerous cellular processes. Because around 70% of the currently marketed drugs target MPs, a detailed understanding of their structure, binding properties, and functional dynamics in a physiologically relevant environment is crucial for a more detailed understanding of this important protein class. We here summarize the benefits of using lipid nanodiscs for NMR structural investigations and provide a detailed overview of the currently used lipid nanodisc systems as well as their applications in solution-state NMR. Despite the increasing use of other structural methods for the structure determination of MPs in lipid nanodiscs, solution NMR turns out to be a versatile tool to probe a wide range of MP features, ranging from the structure determination of small to medium-sized MPs to probing ligand and partner protein binding as well as functionally relevant dynamical signatures in a lipid nanodisc setting. We will expand on these topics by discussing recent NMR studies with lipid nanodiscs and work out a key workflow for optimizing the nanodisc incorporation of an MP for subsequent NMR investigations. With this, we hope to provide a comprehensive background to enable an informed assessment of the applicability of lipid nanodiscs for NMR studies of a particular MP of interest.
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Affiliation(s)
- Umut Günsel
- Bavarian NMR Center (BNMRZ) at the Department of Chemistry, Technical University of Munich, Ernst-Otto-Fischer-Strasse 2, 85748 Garching, Germany
| | - Franz Hagn
- Bavarian NMR Center (BNMRZ) at the Department of Chemistry, Technical University of Munich, Ernst-Otto-Fischer-Strasse 2, 85748 Garching, Germany.,Institute of Structural Biology, Helmholtz Zentrum München, Ingolstädter Landstraße 1, 85764 Neuherberg, Germany
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4
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Sirithanakorn C, Cronan JE. Biotin, a universal and essential cofactor: Synthesis, ligation and regulation. FEMS Microbiol Rev 2021; 45:6081095. [PMID: 33428728 DOI: 10.1093/femsre/fuab003] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Accepted: 01/08/2021] [Indexed: 12/22/2022] Open
Abstract
Biotin is a covalently attached enzyme cofactor required for intermediary metabolism in all three domains of life. Several important human pathogens (e.g. Mycobacterium tuberculosis) require biotin synthesis for pathogenesis. Humans lack a biotin synthetic pathway hence bacterial biotin synthesis is a prime target for new therapeutic agents. The biotin synthetic pathway is readily divided into early and late segments. Although pimelate, a seven carbon α,ω-dicarboxylic acid that contributes seven of the ten biotin carbons atoms, was long known to be a biotin precursor, its biosynthetic pathway was a mystery until the E. coli pathway was discovered in 2010. Since then, diverse bacteria encode evolutionarily distinct enzymes that replace enzymes in the E. coli pathway. Two new bacterial pimelate synthesis pathways have been elucidated. In contrast to the early pathway the late pathway, assembly of the fused rings of the cofactor, was long thought settled. However, a new enzyme that bypasses a canonical enzyme was recently discovered as well as homologs of another canonical enzyme that functions in synthesis of another protein-bound coenzyme, lipoic acid. Most bacteria tightly regulate transcription of the biotin synthetic genes in a biotin-responsive manner. The bifunctional biotin ligases which catalyze attachment of biotin to its cognate enzymes and repress biotin gene transcription are best understood regulatory system.
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Affiliation(s)
- Chaiyos Sirithanakorn
- Faculty of Medicine, King Mongkut's Institute of Technology Ladkrabang, Bangkok, Thailand.,Department of Microbiology, University of Illinois, Urbana, IL 61801, USA
| | - John E Cronan
- Department of Microbiology, University of Illinois, Urbana, IL 61801, USA.,Department of Biochemistry, University of Illinois, Urbana, IL 61801, USA
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5
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Turner ME, Huynh K, Carroll RK, Ahn SJ, Rice KC. Characterization of the Streptococcus mutans SMU.1703c-SMU.1702c Operon Reveals Its Role in Riboflavin Import and Response to Acid Stress. J Bacteriol 2020; 203:e00293-20. [PMID: 33077636 PMCID: PMC7950412 DOI: 10.1128/jb.00293-20] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Accepted: 10/15/2020] [Indexed: 11/20/2022] Open
Abstract
Streptococcus mutans utilizes numerous metabolite transporters to obtain essential nutrients in the "feast or famine" environment of the human mouth. S. mutans and most other streptococci are considered auxotrophic for several essential vitamins including riboflavin (vitamin B2), which is used to generate key cofactors and to perform numerous cellular redox reactions. Despite the well-known contributions of this vitamin to central metabolism, little is known about how S. mutans obtains and metabolizes B2 The uncharacterized protein SMU.1703c displays high sequence homology to the riboflavin transporter RibU. Deletion of SMU.1703c hindered S. mutans growth in complex and defined medium in the absence of saturating levels of exogenous riboflavin, whereas deletion of cotranscribed SMU.1702c alone had no apparent effect on growth. Expression of SMU.1703c in a Bacillus subtilis riboflavin auxotroph functionally complemented growth in nonsaturating riboflavin conditions. S. mutans was also able to grow on flavin adenine dinucleotide (FAD) or flavin mononucleotide (FMN) in an SMU.1703c-dependent manner. Deletion of SMU.1703c and/or SMU.1702c impacted S. mutans acid stress tolerance, as all mutants showed improved growth at pH 5.5 compared to that of the wild type when medium was supplemented with saturating riboflavin. Cooccurrence of SMU.1703c and SMU.1702c, a hypothetical PAP2 family acid phosphatase gene, appears unique to the streptococci and may suggest a connection of SMU.1702c to the acquisition or metabolism of flavins within this genus. Identification of SMU.1703c as a RibU-like riboflavin transporter furthers our understanding of how S. mutans acquires essential micronutrients within the oral cavity and how this pathogen successfully competes within nutrient-starved oral biofilms.IMPORTANCE Dental caries form when acid produced by oral bacteria erodes tooth enamel. This process is driven by the fermentative metabolism of cariogenic bacteria, most notably Streptococcus mutans Nutrient acquisition is key in the competitive oral cavity, and many organisms have evolved various strategies to procure carbon sources or necessary biomolecules. B vitamins, such as riboflavin, which many oral streptococci must scavenge from the oral environment, are necessary for survival within the competitive oral cavity. However, the primary mechanism and proteins involved in this process remain uncharacterized. This study is important because it identifies a key step in S. mutans riboflavin acquisition and cofactor generation, which may enable the development of novel anticaries treatment strategies via selective targeting of metabolite transporters.
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Affiliation(s)
- Matthew E Turner
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida, USA
| | - Khanh Huynh
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida, USA
| | - Ronan K Carroll
- Department of Biological Sciences, Ohio University, Athens, Ohio, USA
| | - Sang-Joon Ahn
- Department of Oral Biology, College of Dentistry, University of Florida, Gainesville, Florida, USA
| | - Kelly C Rice
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida, USA
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6
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Li MJ, Atkins WM, McClary WD. Preparation of Lipid Nanodiscs with Lipid Mixtures. ACTA ACUST UNITED AC 2020; 98:e100. [PMID: 31746556 DOI: 10.1002/cpps.100] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Lipid nanodiscs provide a native-like lipid environment for membrane proteins, and they have become a valuable platform for the study of membrane biophysics. A range of biophysical and biochemical analyses are enabled when membrane proteins are captured in lipid nanodiscs. Two parameters that can be controlled when capturing membrane proteins in lipid nanodiscs are the radius, and hence the surface area of the lipid surface, and the composition of the lipid bilayer. Despite their emergence as a versatile tool, most studies with lipid nanodiscs in the literature have focused on nanodiscs of a single radius with a single lipid. In light of the complexity of biological membranes, it is likely that nanodiscs with multiple membrane components would be more sophisticated models for membrane research. It is possible to prepare nanodiscs with more complex lipid mixtures to probe the effects of lipid composition on several aspects of membrane biochemistry. Detailed protocols are described here for the preparation of nanodiscs with mixtures of phospholipids, incorporation of cholesterol, and incorporation of a spectroscopic lipid probe. These protocols provide starting points for the construction of nanodiscs with more physiological membrane compositions or with useful biophysical probes. © 2019 by John Wiley & Sons, Inc. Basic Protocol 1: Assembly of mixed lipid nanodiscs Basic Protocol 2: Assembly of nanodiscs with cholesterol Basic Protocol 3: Incorporation of laurdan into nanodiscs for membrane fluidity measurements.
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Affiliation(s)
- Mavis Jiarong Li
- Department of Medicinal Chemistry, University of Washington, Seattle, Washington
| | - William M Atkins
- Department of Medicinal Chemistry, University of Washington, Seattle, Washington
| | - Wynton D McClary
- Department of Pharmaceutical Sciences, University of Colorado, Anschutz Medical Campus, Aurora, Colorado
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7
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Abstract
Energy-coupling factor (ECF)-type ATP-binding cassette (ABC) transporters catalyze membrane transport of micronutrients in prokaryotes. Crystal structures and biochemical characterization have revealed that ECF transporters are mechanistically distinct from other ABC transport systems. Notably, ECF transporters make use of small integral membrane subunits (S-components) that are predicted to topple over in the membrane when carrying the bound substrate from the extracellular side of the bilayer to the cytosol. Here, we review the phylogenetic diversity of ECF transporters as well as recent structural and biochemical advancements that have led to the postulation of conceptually different mechanistic models. These models can be described as power stroke and thermal ratchet. Structural data indicate that the lipid composition and bilayer structure are likely to have great impact on the transport function. We argue that study of ECF transporters could lead to generic insight into membrane protein structure, dynamics, and interaction.
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Affiliation(s)
- S Rempel
- Gr oningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9747 AG Groningen, The Netherlands; , ,
| | - W K Stanek
- Gr oningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9747 AG Groningen, The Netherlands; , ,
| | - D J Slotboom
- Gr oningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9747 AG Groningen, The Netherlands; , , .,Zernike Institute for Advanced Materials, University of Groningen, 9747 AG Groningen, The Netherlands
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8
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Finkenwirth F, Sippach M, Pecina SN, Gäde M, Ruta J, Ricke A, Bondarenko E, Klare JP, Zinke M, Lange S, Lange A, Steinhoff HJ, Eitinger T. Dynamic interactions of CbiN and CbiM trigger activity of a cobalt energy-coupling-factor transporter. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2019; 1862:183114. [PMID: 31666178 DOI: 10.1016/j.bbamem.2019.183114] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 10/01/2019] [Accepted: 10/08/2019] [Indexed: 11/26/2022]
Abstract
Energy-coupling factor (ECF) transporters for uptake of vitamins and transition-metal ions into prokaryotic cells share a common architecture consisting of a substrate-specific integral membrane protein (S), a transmembrane coupling protein (T) and two cytoplasmic ATP-binding-cassette-family ATPases. S components rotate within the membrane to expose their binding pockets alternately to the exterior and the cytoplasm. In contrast to vitamin transporters, metal-specific systems rely on additional proteins with essential but poorly understood functions. CbiN, a membrane protein composed of two transmembrane helices tethered by an extracytoplasmic loop of 37 amino-acid residues represents the auxiliary component that temporarily interacts with the CbiMQO2 Co2+ transporter. CbiN was previously shown to induce significant Co2+ transport activity in the absence of CbiQO2 in cells producing the S component CbiM plus CbiN or a Cbi(MN) fusion. Here we analyzed the mode of interaction between the two protein domains. Any deletion in the CbiN loop abolished transport activity. In silico predicted protein-protein contacts between segments of the CbiN loop and loops in CbiM were confirmed by cysteine-scanning mutagenesis and crosslinking. Likewise, an ordered structure of the CbiN loop was observed by electron paramagnetic resonance analysis after site-directed spin labeling. The N-terminal loop of CbiM containing three of four metal ligands was partially immobilized in wild-type Cbi(MN) but completely immobile in inactive variants with CbiN loop deletions. Decreased dynamics of the inactive form was also detected by solid-state nuclear magnetic resonance of isotope-labeled protein in proteoliposomes. In conclusion, CbiM-CbiN loop-loop interactions facilitate metal insertion into the binding pocket.
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Affiliation(s)
- Friedrich Finkenwirth
- Institut für Biologie/Mikrobiologie, Humboldt-Universität zu Berlin, 10099 Berlin, Germany
| | - Michael Sippach
- Fachbereich Physik, Universität Osnabrück, 49076 Osnabrück, Germany
| | - Sinah N Pecina
- Institut für Biologie/Mikrobiologie, Humboldt-Universität zu Berlin, 10099 Berlin, Germany
| | - Mario Gäde
- Institut für Biologie/Mikrobiologie, Humboldt-Universität zu Berlin, 10099 Berlin, Germany
| | - Julia Ruta
- Department of Molecular Biophysics, Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), 13125 Berlin, Germany; Institut für Biologie, Humboldt-Universität zu Berlin, 10099 Berlin, Germany
| | - Adrian Ricke
- Fachbereich Physik, Universität Osnabrück, 49076 Osnabrück, Germany
| | - Elena Bondarenko
- Fachbereich Physik, Universität Osnabrück, 49076 Osnabrück, Germany
| | - Johann P Klare
- Fachbereich Physik, Universität Osnabrück, 49076 Osnabrück, Germany
| | - Maximilian Zinke
- Department of Molecular Biophysics, Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), 13125 Berlin, Germany
| | - Sascha Lange
- Department of Molecular Biophysics, Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), 13125 Berlin, Germany
| | - Adam Lange
- Department of Molecular Biophysics, Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), 13125 Berlin, Germany; Institut für Biologie, Humboldt-Universität zu Berlin, 10099 Berlin, Germany
| | | | - Thomas Eitinger
- Institut für Biologie/Mikrobiologie, Humboldt-Universität zu Berlin, 10099 Berlin, Germany.
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9
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Finkenwirth F, Eitinger T. ECF-type ABC transporters for uptake of vitamins and transition metal ions into prokaryotic cells. Res Microbiol 2019; 170:358-365. [PMID: 31283960 DOI: 10.1016/j.resmic.2019.06.007] [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: 04/18/2019] [Revised: 06/27/2019] [Accepted: 06/29/2019] [Indexed: 12/15/2022]
Abstract
Energy-coupling factor (ECF) transporters mediate the uptake of micronutrients in prokaryotes. They consist of two ATP-binding-cassette family ATPases, a transmembrane coupling protein (T component) and a substrate-binding membrane protein (S component). ECF transporters for Co2+ and Ni2+ ions have one or two additional proteins with extracytoplasmic regions but poorly understood function. Homologs of T components with a predicted localization in plastids are widespread in plants but their physiological role is unclear. S components in eukaryotes are very rare and restricted to biotin-specific variants. Apart from a potential contribution to the export of flavins to serve the assembly of extracytoplasmic electron transfer chains, ECF transporters function as importers.
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Affiliation(s)
- Friedrich Finkenwirth
- Institut für Biologie/Mikrobiologie, Humboldt-Universität zu Berlin, Unter den Linden 6, 10099 Berlin, Germany
| | - Thomas Eitinger
- Institut für Biologie/Mikrobiologie, Humboldt-Universität zu Berlin, Unter den Linden 6, 10099 Berlin, Germany.
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10
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Bousis S, Setyawati I, Diamanti E, Slotboom DJ, Hirsch AKH. Energy-Coupling Factor Transporters as Novel Antimicrobial Targets. ADVANCED THERAPEUTICS 2019. [DOI: 10.1002/adtp.201800066] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Spyridon Bousis
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS) - Helmholtz Centre for Infection Research (HZI); Department of Drug Design and Optimization; Campus Building E8.1 66123 Saarbrücken Germany
- Stratingh Institute for Chemistry; University of Groningen; Nijenborgh 7 9747AG Groningen The Netherlands
- Department of Pharmacy; Saarland University; Saarbrücken, Campus Building E8.1 66123 Saarbrücken Germany
| | - Inda Setyawati
- Groningen Biomolecular Sciences and Biotechnology Institute; University of Groningen; Nijenborgh 4 9747AG Groningen The Netherlands
- Department of Biochemistry; Bogor Agricultural University; Dramaga 16680 Bogor Indonesia
| | - Eleonora Diamanti
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS) - Helmholtz Centre for Infection Research (HZI); Department of Drug Design and Optimization; Campus Building E8.1 66123 Saarbrücken Germany
- Stratingh Institute for Chemistry; University of Groningen; Nijenborgh 7 9747AG Groningen The Netherlands
| | - Dirk J. Slotboom
- Groningen Biomolecular Sciences and Biotechnology Institute; University of Groningen; Nijenborgh 4 9747AG Groningen The Netherlands
- Department of Biochemistry; Bogor Agricultural University; Dramaga 16680 Bogor Indonesia
| | - Anna K. H. Hirsch
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS) - Helmholtz Centre for Infection Research (HZI); Department of Drug Design and Optimization; Campus Building E8.1 66123 Saarbrücken Germany
- Stratingh Institute for Chemistry; University of Groningen; Nijenborgh 7 9747AG Groningen The Netherlands
- Department of Pharmacy; Saarland University; Saarbrücken, Campus Building E8.1 66123 Saarbrücken Germany
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11
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Biotin-mediated growth and gene expression in Staphylococcus aureus is highly responsive to environmental biotin. Appl Microbiol Biotechnol 2018; 102:3793-3803. [PMID: 29508030 DOI: 10.1007/s00253-018-8866-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Revised: 02/11/2018] [Accepted: 02/12/2018] [Indexed: 10/17/2022]
Abstract
Biotin (Vitamin B7) is a critical enzyme co-factor in metabolic pathways important for bacterial survival. Biotin is obtained either from the environment or by de novo synthesis, with some bacteria capable of both. In certain species, the bifunctional protein BirA plays a key role in biotin homeostasis as it regulates expression of biotin biosynthetic enzymes in response to biotin demand and supply. Here, we compare the effect of biotin on the growth of two bacteria that possess a bifunctional BirA, namely Escherichia coli and Staphylococcus aureus. Unlike E. coli that could fulfill its biotin requirements through de novo synthesis, S. aureus showed improved growth rates in media supplemented with 10 nM biotin. S. aureus also accumulated more radiolabeled biotin from the media highlighting its ability to efficiently scavenge exogenous material. These data are consistent with S. aureus colonizing low biotin microhabitats. We also demonstrate that the S. aureus BirA protein is a transcriptional repressor of BioY, a subunit of the biotin transporter, and an operon containing yhfT and yhfS, the products of which have a putative role in fatty acid homeostasis. Increased expression of bioY is proposed to help cue S. aureus for efficient scavenging in low biotin environments.
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12
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Crystal Structure of a Group I Energy Coupling Factor Vitamin Transporter S Component in Complex with Its Cognate Substrate. Cell Chem Biol 2017; 23:827-836. [PMID: 27447050 PMCID: PMC5037267 DOI: 10.1016/j.chembiol.2016.06.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Revised: 05/18/2016] [Accepted: 06/02/2016] [Indexed: 12/27/2022]
Abstract
Energy coupling factor (ECF) transporters are responsible for the uptake of essential scarce nutrients in prokaryotes. This ATP-binding cassette transporter family comprises two subgroups that share a common architecture forming a tripartite membrane protein complex consisting of a translocation component and ATP hydrolyzing module and a substrate-capture (S) component. Here, we present the crystal structure of YkoE from Bacillus subtilis, the S component of the previously uncharacterized group I ECF transporter YkoEDC. Structural and biochemical analyses revealed the constituent residues of the thiamine-binding pocket as well as an unexpected mode of vitamin recognition. In addition, our experimental and bioinformatics data demonstrate major differences between YkoE and group II ECF transporters and indicate how group I vitamin transporter S components have diverged from other group I and group II ECF transporters. The crystal structure of a group I ECF transporter S component was determined The thiamine-bound structure was determined in lipidic environment The structure reveals major differences to group II S components CGMD simulations indicate the orientation of the protein in the membrane
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13
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Faas R, Pohle A, Moß K, Henkel M, Hausmann R. Self-assembly of nanoscale particles with biosurfactants and membrane scaffold proteins. ACTA ACUST UNITED AC 2017; 16:1-4. [PMID: 28948158 PMCID: PMC5602816 DOI: 10.1016/j.btre.2017.08.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Revised: 06/21/2017] [Accepted: 08/28/2017] [Indexed: 10/29/2022]
Abstract
Nanodiscs are membrane mimetics which may be used as tools for biochemical and biophysical studies of a variety of membrane proteins. These nanoscale structures are composed of a phospholipid bilayer held together by an amphipathic membrane scaffold protein (MSP). In the past, nanodiscs were successfully assembled with membrane scaffold protein 1D1 and 1,2-dipalmitoyl-sn-glycero-3-phosphorylcholine with a homogeneous diameter of ∼10 nm. In this study, the formation of nanoscale particles from MSP1D1 and rhamnolipid biosurfactants is investigated. Different protein to lipid ratios of 1:80, 1:90 and 1:100 were used for the assembly reaction, which were consecutively separated, purified and analyzed by size-exclusion chromatography (SEC) and dynamic light scattering (DLS). Size distributions were measured to determine homogeneity and confirm size dimensions. In this study, first evidence is presented on the formation of nanoscale particles with rhamnolipid biosurfactants and membrane scaffold proteins.
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Affiliation(s)
- Ramona Faas
- Institute of Food Science and Biotechnology (150), Department of Bioprocess Engineering (150k), University of Hohenheim, Fruwirthstraße 12, 70599 Stuttgart, Germany
| | - Annelie Pohle
- Institute of Food Science and Biotechnology (150), Department of Bioprocess Engineering (150k), University of Hohenheim, Fruwirthstraße 12, 70599 Stuttgart, Germany
| | - Karin Moß
- Institute of Food Science and Biotechnology (150), Department of Bioprocess Engineering (150k), University of Hohenheim, Fruwirthstraße 12, 70599 Stuttgart, Germany
| | - Marius Henkel
- Institute of Food Science and Biotechnology (150), Department of Bioprocess Engineering (150k), University of Hohenheim, Fruwirthstraße 12, 70599 Stuttgart, Germany
| | - Rudolf Hausmann
- Institute of Food Science and Biotechnology (150), Department of Bioprocess Engineering (150k), University of Hohenheim, Fruwirthstraße 12, 70599 Stuttgart, Germany
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Finkenwirth F, Kirsch F, Eitinger T. Complex Stability During the Transport Cycle of a Subclass I ECF Transporter. Biochemistry 2017; 56:4578-4583. [DOI: 10.1021/acs.biochem.7b00390] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Friedrich Finkenwirth
- Institut für Biologie/Mikrobiologie, Humboldt-Universität zu Berlin, Unter den Linden 6, 10099 Berlin, Germany
| | - Franziska Kirsch
- Institut für Biologie/Mikrobiologie, Humboldt-Universität zu Berlin, Unter den Linden 6, 10099 Berlin, Germany
| | - Thomas Eitinger
- Institut für Biologie/Mikrobiologie, Humboldt-Universität zu Berlin, Unter den Linden 6, 10099 Berlin, Germany
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15
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The Synergetic Effects of Combining Structural Biology and EPR Spectroscopy on Membrane Proteins. CRYSTALS 2017. [DOI: 10.3390/cryst7040117] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Protein structures as provided by structural biology such as X-ray crystallography, cryo-electron microscopy and NMR spectroscopy are key elements to understand the function of a protein on the molecular level. Nonetheless, they might be error-prone due to crystallization artifacts or, in particular in case of membrane-imbedded proteins, a mostly artificial environment. In this review, we will introduce different EPR spectroscopy methods as powerful tools to complement and validate structural data gaining insights in the dynamics of proteins and protein complexes such that functional cycles can be derived. We will highlight the use of EPR spectroscopy on membrane-embedded proteins and protein complexes ranging from receptors to secondary active transporters as structural information is still limited in this field and the lipid environment is a particular challenge.
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16
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Homburg C, Bommer M, Wuttge S, Hobe C, Beck S, Dobbek H, Deutscher J, Licht A, Schneider E. Inducer exclusion in Firmicutes: insights into the regulation of a carbohydrate ATP binding cassette transporter from Lactobacillus casei BL23 by the signal transducing protein P-Ser46-HPr. Mol Microbiol 2017; 105:25-45. [PMID: 28370477 DOI: 10.1111/mmi.13680] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/26/2017] [Indexed: 12/24/2022]
Abstract
Catabolite repression is a mechanism that enables bacteria to control carbon utilization. As part of this global regulatory network, components of the phosphoenolpyruvate:carbohydrate phosphotransferase system inhibit the uptake of less favorable sugars when a preferred carbon source such as glucose is available. This process is termed inducer exclusion. In bacteria belonging to the phylum Firmicutes, HPr, phosphorylated at serine 46 (P-Ser46-HPr) is the key player but its mode of action is elusive. To address this question at the level of purified protein components, we have chosen a homolog of the Escherichia coli maltose/maltodextrin ATP-binding cassette transporter from Lactobacillus casei (MalE1-MalF1G1K12 ) as a model system. We show that the solute binding protein, MalE1, binds linear and cyclic maltodextrins but not maltose. Crystal structures of MalE1 complexed with these sugars provide a clue why maltose is not a substrate. P-Ser46-HPr inhibited MalE1/maltotetraose-stimulated ATPase activity of the transporter incorporated in proteoliposomes. Furthermore, cross-linking experiments revealed that P-Ser46-HPr contacts the nucleotide-binding subunit, MalK1, in proximity to the Walker A motif. However, P-Ser46-HPr did not block binding of ATP to MalK1. Together, our findings provide first biochemical evidence that P-Ser-HPr arrests the transport cycle by preventing ATP hydrolysis at the MalK1 subunits of the transporter.
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Affiliation(s)
- Constanze Homburg
- Institut für Biologie/Physiologie der Mikroorganismen, Humboldt-Universität zu Berlin, Berlin, D-10099, Germany
| | - Martin Bommer
- Institut für Biologie/Strukturbiologie und Biochemie, Humboldt-Universität zu Berlin, Berlin, D-10099, Germany
| | - Steven Wuttge
- Institut für Biologie/Physiologie der Mikroorganismen, Humboldt-Universität zu Berlin, Berlin, D-10099, Germany
| | - Carolin Hobe
- Institut für Biologie/Physiologie der Mikroorganismen, Humboldt-Universität zu Berlin, Berlin, D-10099, Germany
| | - Sebastian Beck
- Institut für Chemie/Angewandte Analytik und Umweltchemie, Humboldt-Universität zu Berlin, Berlin, D-10099, Germany
| | - Holger Dobbek
- Institut für Biologie/Strukturbiologie und Biochemie, Humboldt-Universität zu Berlin, Berlin, D-10099, Germany
| | - Josef Deutscher
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, F-78350, France.,Expression Génétique Microbienne, Institut de Biologie Physico-Chimique, Centre National de la Recherche Scientifique, UMR8261, Paris, F-75005, France
| | - Anke Licht
- Institut für Biologie/Physiologie der Mikroorganismen, Humboldt-Universität zu Berlin, Berlin, D-10099, Germany
| | - Erwin Schneider
- Institut für Biologie/Physiologie der Mikroorganismen, Humboldt-Universität zu Berlin, Berlin, D-10099, Germany
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17
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Abstract
Membrane proteins play a most important part in metabolism, signaling, cell motility, transport, development, and many other biochemical and biophysical processes which constitute fundamentals of life on the molecular level. Detailed understanding of these processes is necessary for the progress of life sciences and biomedical applications. Nanodiscs provide a new and powerful tool for a broad spectrum of biochemical and biophysical studies of membrane proteins and are commonly acknowledged as an optimal membrane mimetic system that provides control over size, composition, and specific functional modifications on the nanometer scale. In this review we attempted to combine a comprehensive list of various applications of nanodisc technology with systematic analysis of the most attractive features of this system and advantages provided by nanodiscs for structural and mechanistic studies of membrane proteins.
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Affiliation(s)
- Ilia G Denisov
- Department of Biochemistry and Department of Chemistry, University of Illinois , Urbana, Illinois 61801, United States
| | - Stephen G Sligar
- Department of Biochemistry and Department of Chemistry, University of Illinois , Urbana, Illinois 61801, United States
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18
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Structure and mechanism of a group-I cobalt energy coupling factor transporter. Cell Res 2017; 27:675-687. [PMID: 28322252 DOI: 10.1038/cr.2017.38] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Revised: 02/08/2017] [Accepted: 02/15/2017] [Indexed: 12/20/2022] Open
Abstract
Energy-coupling factor (ECF) transporters are a large family of ATP-binding cassette transporters recently identified in microorganisms. Responsible for micronutrient uptake from the environment, ECF transporters are modular transporters composed of a membrane substrate-binding component EcfS and an ECF module consisting of an integral membrane scaffold component EcfT and two cytoplasmic ATP binding/hydrolysis components EcfA/A'. ECF transporters are classified into groups I and II. Currently, the molecular understanding of group-I ECF transporters is very limited, partly due to a lack of transporter complex structural information. Here, we present structures and structure-based analyses of the group-I cobalt ECF transporter CbiMNQO, whose constituting subunits CbiM/CbiN, CbiQ, and CbiO correspond to the EcfS, EcfT, and EcfA components of group-II ECF transporters, respectively. Through reconstitution of different CbiMNQO subunits and determination of related ATPase and transporter activities, the substrate-binding subunit CbiM was found to stimulate CbiQO's basal ATPase activity. The structure of CbiMQO complex was determined in its inward-open conformation and that of CbiO in β, γ-methyleneadenosine 5'-triphosphate-bound closed conformation. Structure-based analyses revealed interactions between different components, substrate-gating function of the L1 loop of CbiM, and conformational changes of CbiO induced by ATP binding and product release within the CbiMNQO transporter complex. These findings enabled us to propose a working model of the CbiMNQO transporter, in which the transport process requires the rotation or toppling of both CbiQ and CbiM, and CbiN might function in coupling conformational changes between CbiQ and CbiM.
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19
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Lewinson O, Livnat-Levanon N. Mechanism of Action of ABC Importers: Conservation, Divergence, and Physiological Adaptations. J Mol Biol 2017; 429:606-619. [PMID: 28104364 DOI: 10.1016/j.jmb.2017.01.010] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Revised: 01/03/2017] [Accepted: 01/04/2017] [Indexed: 01/08/2023]
Abstract
The past decade has seen a remarkable surge in structural characterization of ATP binding cassette (ABC) transporters, which have spurred a more focused functional analysis of these elaborate molecular machines. As a result, it has become increasingly apparent that there is a substantial degree of mechanistic variation between ABC transporters that function as importers, which correlates with their physiological roles. Here, we summarize recent advances in ABC importers' structure-function studies and provide an explanation as to the origin of the different mechanisms of action.
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Affiliation(s)
- Oded Lewinson
- Department of Biochemistry, The Bruce and Ruth Rappaport Faculty of Medicine, The Technion-Israel Institute of Technology, 31096 Haifa, Israel.
| | - Nurit Livnat-Levanon
- Department of Biochemistry, The Bruce and Ruth Rappaport Faculty of Medicine, The Technion-Israel Institute of Technology, 31096 Haifa, Israel
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20
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Jia B, Zhu XF, Pu ZJ, Duan YX, Hao LJ, Zhang J, Chen LQ, Jeon CO, Xuan YH. Integrative View of the Diversity and Evolution of SWEET and SemiSWEET Sugar Transporters. FRONTIERS IN PLANT SCIENCE 2017; 8:2178. [PMID: 29326750 PMCID: PMC5742349 DOI: 10.3389/fpls.2017.02178] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Accepted: 12/12/2017] [Indexed: 05/21/2023]
Abstract
Sugars Will Eventually be Exported Transporter (SWEET) and SemiSWEET are recently characterized families of sugar transporters in eukaryotes and prokaryotes, respectively. SemiSWEETs contain 3 transmembrane helices (TMHs), while SWEETs contain 7. Here, we performed sequence-based comprehensive analyses for SWEETs and SemiSWEETs across the biosphere. In total, 3,249 proteins were identified and ≈60% proteins were found in green plants and Oomycota, which include a number of important plant pathogens. Protein sequence similarity networks indicate that proteins from different organisms are significantly clustered. Of note, SemiSWEETs with 3 or 4 TMHs that may fuse to SWEET were identified in plant genomes. 7-TMH SWEETs were found in bacteria, implying that SemiSWEET can be fused directly in prokaryote. 15-TMH extraSWEET and 25-TMH superSWEET were also observed in wild rice and oomycetes, respectively. The transporters can be classified into 4, 2, 2, and 2 clades in plants, Metazoa, unicellular eukaryotes, and prokaryotes, respectively. The consensus and coevolution of amino acids in SWEETs were identified by multiple sequence alignments. The functions of the highly conserved residues were analyzed by molecular dynamics analysis. The 19 most highly conserved residues in the SWEETs were further confirmed by point mutagenesis using SWEET1 from Arabidopsis thaliana. The results proved that the conserved residues located in the extrafacial gate (Y57, G58, G131, and P191), the substrate binding pocket (N73, N192, and W176), and the intrafacial gate (P43, Y83, F87, P145, M161, P162, and Q202) play important roles for substrate recognition and transport processes. Taken together, our analyses provide a foundation for understanding the diversity, classification, and evolution of SWEETs and SemiSWEETs using large-scale sequence analysis and further show that gene duplication and gene fusion are important factors driving the evolution of SWEETs.
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Affiliation(s)
- Baolei Jia
- School of Bioengineering, Qilu University of Technology, Jinan, China
- Department of Life Sciences, Chung-Ang University, Seoul, South Korea
- *Correspondence: Baolei Jia
| | - Xiao Feng Zhu
- College of Plant Protection, Shenyang Agricultural University, Shenyang, China
| | - Zhong Ji Pu
- School of Life Science and Biotechnology, Dalian University of Technology, Dalian, China
| | - Yu Xi Duan
- College of Plant Protection, Shenyang Agricultural University, Shenyang, China
| | - Lu Jiang Hao
- School of Bioengineering, Qilu University of Technology, Jinan, China
| | - Jie Zhang
- School of Bioengineering, Qilu University of Technology, Jinan, China
| | - Li-Qing Chen
- Department of Plant Biology, University of Illinois at Urbana–Champaign, Urbana, IL, United States
| | - Che Ok Jeon
- Department of Life Sciences, Chung-Ang University, Seoul, South Korea
- Che Ok Jeon
| | - Yuan Hu Xuan
- College of Plant Protection, Shenyang Agricultural University, Shenyang, China
- Yuan Hu Xuan
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21
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Structural insight in the toppling mechanism of an energy-coupling factor transporter. Nat Commun 2016; 7:11072. [PMID: 27026363 PMCID: PMC4820897 DOI: 10.1038/ncomms11072] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Accepted: 02/17/2016] [Indexed: 11/08/2022] Open
Abstract
Energy-coupling factor (ECF) transporters mediate uptake of micronutrients in prokaryotes. The transporters consist of an S-component that binds the transported substrate and an ECF module (EcfAA′T) that binds and hydrolyses ATP. The mechanism of transport is poorly understood but presumably involves an unusual step in which the membrane-embedded S-component topples over to carry the substrate across the membrane. In many ECF transporters, the S-component dissociates from the ECF module after transport. Subsequently, substrate-bound S-components out-compete the empty proteins for re-binding to the ECF module in a new round of transport. Here we present crystal structures of the folate-specific transporter ECF–FolT from Lactobacillus delbrueckii. Interaction of the ECF module with FolT stabilizes the toppled state, and simultaneously destroys the high-affinity folate-binding site, allowing substrate release into the cytosol. We hypothesize that differences in the kinetics of toppling can explain how substrate-loaded FolT out-competes apo-FolT for association with the ECF module. Prokaryotes use energy-coupling factor transporters to uptake required micronutrients and an unusual toppling mechanism has been proposed for their function. Here, the authors provide structural support for this mechanism, allowing direct visualization of the toppled state.
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