1
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Wu Y, Bell A, Thomas GH, Bolam DN, Sargent F, Juge N, Palmer T, Severi E. Characterisation of anhydro-sialic acid transporters from mucosa-associated bacteria. MICROBIOLOGY (READING, ENGLAND) 2024; 170:001448. [PMID: 38488830 PMCID: PMC10955332 DOI: 10.1099/mic.0.001448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Accepted: 02/29/2024] [Indexed: 03/19/2024]
Abstract
Sialic acid (Sia) transporters are critical to the capacity of host-associated bacteria to utilise Sia for growth and/or cell surface modification. While N-acetyl-neuraminic acid (Neu5Ac)-specific transporters have been studied extensively, little is known on transporters dedicated to anhydro-Sia forms such as 2,7-anhydro-Neu5Ac (2,7-AN) or 2,3-dehydro-2-deoxy-Neu5Ac (Neu5Ac2en). Here, we used a Sia-transport-null strain of Escherichia coli to investigate the function of members of anhydro-Sia transporter families previously identified by computational studies. First, we showed that the transporter NanG, from the Glycoside-Pentoside-Hexuronide:cation symporter family, is a specific 2,7-AN transporter, and identified by mutagenesis a crucial functional residue within the putative substrate-binding site. We then demonstrated that NanX transporters, of the Major Facilitator Superfamily, also only transport 2,7-AN and not Neu5Ac2en nor Neu5Ac. Finally, we provided evidence that SiaX transporters, of the Sodium-Solute Symporter superfamily, are promiscuous Neu5Ac/Neu5Ac2en transporters able to acquire either substrate equally well. The characterisation of anhydro-Sia transporters expands our current understanding of prokaryotic Sia metabolism within host-associated microbial communities.
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Affiliation(s)
- Yunhan Wu
- Microbes in Health and Disease, Biosciences Institute, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, UK
| | - Andrew Bell
- Quadram Institute Bioscience, Gut Microbes and Health Institute Strategic Programme, Rosalind Franklin Road, Norwich Research Park, Norwich NR4 7UQ, UK
| | - Gavin H. Thomas
- Department of Biology and York Biomedical Research Institute (YBRI), Wentworth Way, University of York, York YO10 5DD, UK
| | - David N. Bolam
- Microbes in Health and Disease, Biosciences Institute, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, UK
| | - Frank Sargent
- Microbes in Health and Disease, Biosciences Institute, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, UK
| | - Nathalie Juge
- Quadram Institute Bioscience, Gut Microbes and Health Institute Strategic Programme, Rosalind Franklin Road, Norwich Research Park, Norwich NR4 7UQ, UK
| | - Tracy Palmer
- Microbes in Health and Disease, Biosciences Institute, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, UK
| | - Emmanuele Severi
- Microbes in Health and Disease, Biosciences Institute, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, UK
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2
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Currie MJ, Davies JS, Scalise M, Gulati A, Wright JD, Newton-Vesty MC, Abeysekera GS, Subramanian R, Wahlgren WY, Friemann R, Allison JR, Mace PD, Griffin MDW, Demeler B, Wakatsuki S, Drew D, Indiveri C, Dobson RCJ, North RA. Structural and biophysical analysis of a Haemophilus influenzae tripartite ATP-independent periplasmic (TRAP) transporter. eLife 2024; 12:RP92307. [PMID: 38349818 PMCID: PMC10942642 DOI: 10.7554/elife.92307] [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] [Indexed: 02/15/2024] Open
Abstract
Tripartite ATP-independent periplasmic (TRAP) transporters are secondary-active transporters that receive their substrates via a soluble-binding protein to move bioorganic acids across bacterial or archaeal cell membranes. Recent cryo-electron microscopy (cryo-EM) structures of TRAP transporters provide a broad framework to understand how they work, but the mechanistic details of transport are not yet defined. Here we report the cryo-EM structure of the Haemophilus influenzae N-acetylneuraminate TRAP transporter (HiSiaQM) at 2.99 Å resolution (extending to 2.2 Å at the core), revealing new features. The improved resolution (the previous HiSiaQM structure is 4.7 Å resolution) permits accurate assignment of two Na+ sites and the architecture of the substrate-binding site, consistent with mutagenic and functional data. Moreover, rather than a monomer, the HiSiaQM structure is a homodimer. We observe lipids at the dimer interface, as well as a lipid trapped within the fusion that links the SiaQ and SiaM subunits. We show that the affinity (KD) for the complex between the soluble HiSiaP protein and HiSiaQM is in the micromolar range and that a related SiaP can bind HiSiaQM. This work provides key data that enhances our understanding of the 'elevator-with-an-operator' mechanism of TRAP transporters.
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Affiliation(s)
- Michael J Currie
- Biomolecular Interaction Centre, Maurice Wilkins Centre for Biodiscovery, MacDiarmid Institute for Advanced Materials and Nanotechnology, and School of Biological Sciences, University of CanterburyChristchurchNew Zealand
| | - James S Davies
- Biomolecular Interaction Centre, Maurice Wilkins Centre for Biodiscovery, MacDiarmid Institute for Advanced Materials and Nanotechnology, and School of Biological Sciences, University of CanterburyChristchurchNew Zealand
- Department of Biochemistry and Biophysics, Stockholm UniversityStockholmSweden
| | - Mariafrancesca Scalise
- Department DiBEST (Biologia, Ecologia, Scienze della Terra) Unit of Biochemistry and Molecular Biotechnology, University of CalabriaArcavacata di RendeItaly
| | - Ashutosh Gulati
- Department of Biochemistry and Biophysics, Stockholm UniversityStockholmSweden
| | - Joshua D Wright
- Biomolecular Interaction Centre, Maurice Wilkins Centre for Biodiscovery, MacDiarmid Institute for Advanced Materials and Nanotechnology, and School of Biological Sciences, University of CanterburyChristchurchNew Zealand
| | - Michael C Newton-Vesty
- Biomolecular Interaction Centre, Maurice Wilkins Centre for Biodiscovery, MacDiarmid Institute for Advanced Materials and Nanotechnology, and School of Biological Sciences, University of CanterburyChristchurchNew Zealand
| | - Gayan S Abeysekera
- Biomolecular Interaction Centre, Maurice Wilkins Centre for Biodiscovery, MacDiarmid Institute for Advanced Materials and Nanotechnology, and School of Biological Sciences, University of CanterburyChristchurchNew Zealand
| | - Ramaswamy Subramanian
- Biological Sciences and Biomedical Engineering, Bindley Bioscience Center, Purdue University West LafayetteWest LafayetteUnited States
| | - Weixiao Y Wahlgren
- Department of Chemistry and Molecular Biology, Biochemistry and Structural Biology, University of GothenburgGothenburgSweden
| | - Rosmarie Friemann
- Centre for Antibiotic Resistance Research (CARe) at University of GothenburgGothenburgSweden
| | - Jane R Allison
- Biomolecular Interaction Centre, Digital Life Institute, Maurice Wilkins Centre for Molecular Biodiscovery, and School of Biological Sciences, University of AucklandAucklandNew Zealand
| | - Peter D Mace
- Biochemistry Department, School of Biomedical Sciences, University of OtagoDunedinNew Zealand
| | - Michael DW Griffin
- ARC Centre for Cryo-electron Microscopy of Membrane Proteins, Bio Molecular Science and Biotechnology Institute, Department of Biochemistry and Pharmacology, University of MelbourneMelbourneAustralia
| | - Borries Demeler
- Department of Chemistry and Biochemistry, University of MontanaMissoulaUnited States
- Department of Chemistry and Biochemistry, University of LethbridgeLethbridgeCanada
| | - Soichi Wakatsuki
- Biological Sciences Division, SLAC National Accelerator LaboratoryMenlo ParkUnited States
- Department of Structural Biology, Stanford University School of MedicineStanfordUnited States
| | - David Drew
- Department of Biochemistry and Biophysics, Stockholm UniversityStockholmSweden
| | - Cesare Indiveri
- Department DiBEST (Biologia, Ecologia, Scienze della Terra) Unit of Biochemistry and Molecular Biotechnology, University of CalabriaArcavacata di RendeItaly
- CNR Institute of Biomembranes, Bioenergetics and Molecular Biotechnologies (IBIOM)BariItaly
| | - Renwick CJ Dobson
- Biomolecular Interaction Centre, Maurice Wilkins Centre for Biodiscovery, MacDiarmid Institute for Advanced Materials and Nanotechnology, and School of Biological Sciences, University of CanterburyChristchurchNew Zealand
- ARC Centre for Cryo-electron Microscopy of Membrane Proteins, Bio Molecular Science and Biotechnology Institute, Department of Biochemistry and Pharmacology, University of MelbourneMelbourneAustralia
| | - Rachel A North
- Department of Biochemistry and Biophysics, Stockholm UniversityStockholmSweden
- School of Medical Sciences, Faculty of Medicine and Health, University of SydneySydneyAustralia
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3
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Davies JS, Currie MJ, Dobson RCJ, Horne CR, North RA. TRAPs: the 'elevator-with-an-operator' mechanism. Trends Biochem Sci 2024; 49:134-144. [PMID: 38102017 DOI: 10.1016/j.tibs.2023.11.006] [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] [Received: 09/01/2023] [Revised: 11/18/2023] [Accepted: 11/21/2023] [Indexed: 12/17/2023]
Abstract
Tripartite ATP-independent periplasmic (TRAP) transporters are nutrient-uptake systems found in bacteria and archaea. These evolutionary divergent transporter systems couple a substrate-binding protein (SBP) to an elevator-type secondary transporter, which is a first-of-its-kind mechanism of transport. Here, we highlight breakthrough TRAP transporter structures and recent functional data that probe the mechanism of transport. Furthermore, we discuss recent structural and biophysical studies of the ion transporter superfamily (ITS) members and highlight mechanistic principles that are relevant for further exploration of the TRAP transporter system.
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Affiliation(s)
- James S Davies
- Department of Biochemistry and Biophysics, Stockholm University, 106 91 Stockholm, Sweden
| | - Michael J Currie
- Biomolecular Interaction Centre, Maurice Wilkins Centre for Biodiscovery, MacDiarmid Institute for Advanced Materials and Nanotechnology, Christchurch 8140, New Zealand; School of Biological Sciences, University of Canterbury, Christchurch 8140, New Zealand
| | - Renwick C J Dobson
- Biomolecular Interaction Centre, Maurice Wilkins Centre for Biodiscovery, MacDiarmid Institute for Advanced Materials and Nanotechnology, Christchurch 8140, New Zealand; School of Biological Sciences, University of Canterbury, Christchurch 8140, New Zealand; Bio21 Molecular Science and Biotechnology Institute, Department of Biochemistry and Pharmacology, University of Melbourne, Parkville, VIC 3010, Australia
| | - Christopher R Horne
- Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, VIC 3052, Australia; Department of Medical Biology, University of Melbourne, Parkville, VIC 3052, Australia; Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Parkville, VIC 3052, Australia.
| | - Rachel A North
- Department of Biochemistry and Biophysics, Stockholm University, 106 91 Stockholm, Sweden; School of Medical Sciences, Faculty of Medicine and Health, University of Sydney, Sydney, NSW 2006, Australia.
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4
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Peter MF, Ruland JA, Kim Y, Hendricks P, Schneberger N, Siebrasse JP, Thomas GH, Kubitscheck U, Hagelueken G. Conformational coupling of the sialic acid TRAP transporter HiSiaQM with its substrate binding protein HiSiaP. Nat Commun 2024; 15:217. [PMID: 38191530 PMCID: PMC10774421 DOI: 10.1038/s41467-023-44327-3] [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: 03/03/2023] [Accepted: 12/08/2023] [Indexed: 01/10/2024] Open
Abstract
The tripartite ATP-independent periplasmic (TRAP) transporters use an extra cytoplasmic substrate binding protein (SBP) to transport a wide variety of substrates in bacteria and archaea. The SBP can adopt an open- or closed state depending on the presence of substrate. The two transmembrane domains of TRAP transporters form a monomeric elevator whose function is strictly dependent on the presence of a sodium ion gradient. Insights from experimental structures, structural predictions and molecular modeling have suggested a conformational coupling between the membrane elevator and the substrate binding protein. Here, we use a disulfide engineering approach to lock the TRAP transporter HiSiaPQM from Haemophilus influenzae in different conformational states. The SBP, HiSiaP, is locked in its substrate-bound form and the transmembrane elevator, HiSiaQM, is locked in either its assumed inward- or outward-facing states. We characterize the disulfide-locked constructs and use single-molecule total internal reflection fluorescence (TIRF) microscopy to study their interactions. Our experiments demonstrate that the SBP and the transmembrane elevator are indeed conformationally coupled, meaning that the open and closed state of the SBP recognize specific conformational states of the transporter and vice versa.
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Affiliation(s)
- Martin F Peter
- Institute of Structural Biology, University of Bonn, Venusberg-Campus 1, 53127, Bonn, Germany
- Biochemistry Center, Heidelberg University, Im Neuenheimer Feld 328, 69120, Heidelberg, Germany
| | - Jan A Ruland
- Clausius Institute for Physical and Theoretical Chemistry, University of Bonn, Wegelerstr. 12, 53115, Bonn, Germany
| | - Yeojin Kim
- Institute of Structural Biology, University of Bonn, Venusberg-Campus 1, 53127, Bonn, Germany
| | - Philipp Hendricks
- Institute of Structural Biology, University of Bonn, Venusberg-Campus 1, 53127, Bonn, Germany
| | - Niels Schneberger
- Institute of Structural Biology, University of Bonn, Venusberg-Campus 1, 53127, Bonn, Germany
| | - Jan Peter Siebrasse
- Clausius Institute for Physical and Theoretical Chemistry, University of Bonn, Wegelerstr. 12, 53115, Bonn, Germany
| | - Gavin H Thomas
- Department of Biology (Area 10), University of York, York, YO10 5YW, UK
| | - Ulrich Kubitscheck
- Clausius Institute for Physical and Theoretical Chemistry, University of Bonn, Wegelerstr. 12, 53115, Bonn, Germany
| | - Gregor Hagelueken
- Institute of Structural Biology, University of Bonn, Venusberg-Campus 1, 53127, Bonn, Germany.
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5
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Roden A, Engelin MK, Pos KM, Geertsma ER. Membrane-anchored substrate binding proteins are deployed in secondary TAXI transporters. Biol Chem 2023:hsz-2022-0337. [PMID: 36916166 DOI: 10.1515/hsz-2022-0337] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2022] [Accepted: 02/10/2023] [Indexed: 03/16/2023]
Abstract
Substrate-binding proteins (SBPs) are part of solute transport systems and serve to increase substrate affinity and uptake rates. In contrast to primary transport systems, the mechanism of SBP-dependent secondary transport is not well understood. Functional studies have thus far focused on Na+-coupled Tripartite ATP-independent periplasmic (TRAP) transporters for sialic acid. Herein, we report the in vitro functional characterization of TAXIPm-PQM from the human pathogen Proteus mirabilis. TAXIPm-PQM belongs to a TRAP-subfamily using a different type of SBP, designated TRAP-associated extracytoplasmic immunogenic (TAXI) protein. TAXIPm-PQM catalyzes proton-dependent α-ketoglutarate symport and its SBP is an essential component of the transport mechanism. Importantly, TAXIPm-PQM represents the first functionally characterized SBP-dependent secondary transporter that does not rely on a soluble SBP, but uses a membrane-anchored SBP instead.
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Affiliation(s)
- Anja Roden
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Max-von-Laue-Strasse 9, D-60438 Frankfurt am Main, Germany
| | - Melanie K Engelin
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Max-von-Laue-Strasse 9, D-60438 Frankfurt am Main, Germany
| | - Klaas M Pos
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Max-von-Laue-Strasse 9, D-60438 Frankfurt am Main, Germany
| | - Eric R Geertsma
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Max-von-Laue-Strasse 9, D-60438 Frankfurt am Main, Germany.,Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, D-01307 Dresden, Germany
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6
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Davies JS, Currie MJ, North RA, Scalise M, Wright JD, Copping JM, Remus DM, Gulati A, Morado DR, Jamieson SA, Newton-Vesty MC, Abeysekera GS, Ramaswamy S, Friemann R, Wakatsuki S, Allison JR, Indiveri C, Drew D, Mace PD, Dobson RCJ. Structure and mechanism of a tripartite ATP-independent periplasmic TRAP transporter. Nat Commun 2023; 14:1120. [PMID: 36849793 PMCID: PMC9971032 DOI: 10.1038/s41467-023-36590-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2022] [Accepted: 02/07/2023] [Indexed: 03/01/2023] Open
Abstract
In bacteria and archaea, tripartite ATP-independent periplasmic (TRAP) transporters uptake essential nutrients. TRAP transporters receive their substrates via a secreted soluble substrate-binding protein. How a sodium ion-driven secondary active transporter is strictly coupled to a substrate-binding protein is poorly understood. Here we report the cryo-EM structure of the sialic acid TRAP transporter SiaQM from Photobacterium profundum at 2.97 Å resolution. SiaM comprises a "transport" domain and a "scaffold" domain, with the transport domain consisting of helical hairpins as seen in the sodium ion-coupled elevator transporter VcINDY. The SiaQ protein forms intimate contacts with SiaM to extend the size of the scaffold domain, suggesting that TRAP transporters may operate as monomers, rather than the typically observed oligomers for elevator-type transporters. We identify the Na+ and sialic acid binding sites in SiaM and demonstrate a strict dependence on the substrate-binding protein SiaP for uptake. We report the SiaP crystal structure that, together with docking studies, suggest the molecular basis for how sialic acid is delivered to the SiaQM transporter complex. We thus propose a model for substrate transport by TRAP proteins, which we describe herein as an 'elevator-with-an-operator' mechanism.
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Affiliation(s)
- James S Davies
- Biomolecular Interaction Centre, Maurice Wilkins Centre for Biodiscovery, MacDiarmid Institute for Advanced Materials and Nanotechnology and School of Biological Sciences, University of Canterbury, PO Box 4800, Christchurch, 8140, New Zealand.,Department of Biochemistry and Biophysics, Stockholm University, 10691, Stockholm, Sweden
| | - Michael J Currie
- Biomolecular Interaction Centre, Maurice Wilkins Centre for Biodiscovery, MacDiarmid Institute for Advanced Materials and Nanotechnology and School of Biological Sciences, University of Canterbury, PO Box 4800, Christchurch, 8140, New Zealand
| | - Rachel A North
- Biomolecular Interaction Centre, Maurice Wilkins Centre for Biodiscovery, MacDiarmid Institute for Advanced Materials and Nanotechnology and School of Biological Sciences, University of Canterbury, PO Box 4800, Christchurch, 8140, New Zealand. .,Department of Biochemistry and Biophysics, Stockholm University, 10691, Stockholm, Sweden.
| | - Mariafrancesca Scalise
- Department DiBEST (Biologia, Ecologia, Scienze della Terra) Unit of Biochemistry and Molecular Biotechnology, University of Calabria, Via P. Bucci 4C, 87036, Arcavacata di Rende, Italy
| | - Joshua D Wright
- Biomolecular Interaction Centre, Maurice Wilkins Centre for Biodiscovery, MacDiarmid Institute for Advanced Materials and Nanotechnology and School of Biological Sciences, University of Canterbury, PO Box 4800, Christchurch, 8140, New Zealand
| | - Jack M Copping
- Biomolecular Interaction Centre, Digital Life Institute, Maurice Wilkins Centre for Molecular Biodiscovery, and School of Biological Sciences, University of Auckland, Auckland, 1010, New Zealand
| | - Daniela M Remus
- Biomolecular Interaction Centre, Maurice Wilkins Centre for Biodiscovery, MacDiarmid Institute for Advanced Materials and Nanotechnology and School of Biological Sciences, University of Canterbury, PO Box 4800, Christchurch, 8140, New Zealand
| | - Ashutosh Gulati
- Department of Biochemistry and Biophysics, Stockholm University, 10691, Stockholm, Sweden
| | - Dustin R Morado
- Science for Life Laboratory, Department of Biochemistry and Biophysics, Stockholm University, 17165, Solna, Sweden
| | - Sam A Jamieson
- Biochemistry Department, School of Biomedical Sciences, University of Otago, Dunedin, 9054, New Zealand
| | - Michael C Newton-Vesty
- Biomolecular Interaction Centre, Maurice Wilkins Centre for Biodiscovery, MacDiarmid Institute for Advanced Materials and Nanotechnology and School of Biological Sciences, University of Canterbury, PO Box 4800, Christchurch, 8140, New Zealand
| | - Gayan S Abeysekera
- Biomolecular Interaction Centre, Maurice Wilkins Centre for Biodiscovery, MacDiarmid Institute for Advanced Materials and Nanotechnology and School of Biological Sciences, University of Canterbury, PO Box 4800, Christchurch, 8140, New Zealand
| | - Subramanian Ramaswamy
- Biological Sciences and Biomedical Engineering, Bindley Bioscience Center, Purdue University, 1203 W State St, West Lafayette, IN 47906, USA
| | - Rosmarie Friemann
- Centre for Antibiotic Resistance Research (CARe) at University of Gothenburg, Box 440, S-40530, Gothenburg, Sweden
| | - Soichi Wakatsuki
- Biological Sciences Division, SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA.,Department of Structural Biology, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Jane R Allison
- Biomolecular Interaction Centre, Digital Life Institute, Maurice Wilkins Centre for Molecular Biodiscovery, and School of Biological Sciences, University of Auckland, Auckland, 1010, New Zealand
| | - Cesare Indiveri
- Department DiBEST (Biologia, Ecologia, Scienze della Terra) Unit of Biochemistry and Molecular Biotechnology, University of Calabria, Via P. Bucci 4C, 87036, Arcavacata di Rende, Italy.,CNR Institute of Biomembranes, Bioenergetics and Molecular Biotechnologies (IBIOM), Via Amendola 122/O, 70126, Bari, Italy
| | - David Drew
- Department of Biochemistry and Biophysics, Stockholm University, 10691, Stockholm, Sweden
| | - Peter D Mace
- Biochemistry Department, School of Biomedical Sciences, University of Otago, Dunedin, 9054, New Zealand
| | - Renwick C J Dobson
- Biomolecular Interaction Centre, Maurice Wilkins Centre for Biodiscovery, MacDiarmid Institute for Advanced Materials and Nanotechnology and School of Biological Sciences, University of Canterbury, PO Box 4800, Christchurch, 8140, New Zealand. .,Bio21 Molecular Science and Biotechnology Institute, Department of Biochemistry and Molecular Biology, University of Melbourne, Parkville, Victoria, 3010, Australia.
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7
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Bell A, Severi E, Owen CD, Latousakis D, Juge N. Biochemical and structural basis of sialic acid utilization by gut microbes. J Biol Chem 2023; 299:102989. [PMID: 36758803 PMCID: PMC10017367 DOI: 10.1016/j.jbc.2023.102989] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 02/01/2023] [Accepted: 02/02/2023] [Indexed: 02/10/2023] Open
Abstract
The human gastrointestinal (GI) tract harbors diverse microbial communities collectively known as the gut microbiota that exert a profound impact on human health and disease. The repartition and availability of sialic acid derivatives in the gut have a significant impact on the modulation of gut microbes and host susceptibility to infection and inflammation. Although N-acetylneuraminic acid (Neu5Ac) is the main form of sialic acids in humans, the sialic acid family regroups more than 50 structurally and chemically distinct modified derivatives. In the GI tract, sialic acids are found in the terminal location of mucin glycan chains constituting the mucus layer and also come from human milk oligosaccharides in the infant gut or from meat-based foods in adults. The repartition of sialic acid in the GI tract influences the gut microbiota composition and pathogen colonization. In this review, we provide an update on the mechanisms underpinning sialic acid utilization by gut microbes, focusing on sialidases, transporters, and metabolic enzymes.
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Affiliation(s)
- Andrew Bell
- Quadram Institute Bioscience, Gut Microbes and Health Institute Strategic Programme, Norwich, United Kingdom
| | - Emmanuele Severi
- Microbes in Health and Disease, Biosciences Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - C David Owen
- Diamond Light Source Ltd, Diamond House, Harwell Science and Innovation Campus, Didcot, United Kingdom
| | - Dimitrios Latousakis
- Quadram Institute Bioscience, Gut Microbes and Health Institute Strategic Programme, Norwich, United Kingdom
| | - Nathalie Juge
- Quadram Institute Bioscience, Gut Microbes and Health Institute Strategic Programme, Norwich, United Kingdom.
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8
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Liang B, Zhang X, Meng C, Wang L, Yang J. Directed evolution of tripartite ATP-independent periplasmic transporter for 3-Hydroxypropionate biosynthesis. Appl Microbiol Biotechnol 2023; 107:663-676. [PMID: 36525041 DOI: 10.1007/s00253-022-12330-1] [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] [Received: 08/17/2022] [Revised: 10/28/2022] [Accepted: 12/06/2022] [Indexed: 12/23/2022]
Abstract
Our previous study's introduction of the malonic acid assimilation pathway into Escherichia coli enabled biosynthesis of 3-Hydroxypropionate (3-HP) from malonate. However, the relatively low uptake activity of tripartite ATP-independent periplasmic (TRAP) malonic acid transporter (MatPQM) is considered rate-limiting in malonate utilization. Here, to improve the transport performance of this importer, MatP variants were obtained via directed evolution and a novel developed enzyme-inhibition-based high throughput screening approach. This plate chromogenic screening method is based on the fact that malonic acid inhibits both of succinate dehydrogenase activity and further the capability of the reduction of methylene-blue to methylene-white. The best mutant E103G/S194G/Y218H/L235P/N272S showed twofold increased transport efficiency compared to the wild-type. ITC assay and structural analysis revealed that increased binding affinity of the mutant to the ligand was the reason for improved uptake activity of MatPQM. Finally, the engineered strain harboring the evolved mutant produced 20.08 g/L 3-HP with the yield of 0.87 mol/mol malonate in a bioreactor. Therefore, the well-established directed evolution strategy can be regarded as the reference work for other TRAP-type transporters engineering. And, this transporter mutant with enhanced malonic acid uptake activity has broad applications in the microbial biosynthesis of malonyl-CoA-derived valuable compounds in bacteria. KEY POINTS: • We reported directed evolution of a TRAP-type malonic acid transporter. • We found the enhanced malonate uptake activity of mutant lies in improved affinity. • We enhanced 3-HP bioproduction with high yield by employing the best mutant.
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Affiliation(s)
- Bo Liang
- College of Food Science & Engineering, Qingdao Special Food Research Institute, Qingdao Agricultural University, Qingdao, China
- Shandong Key Lab of Applied Mycology, College of Life Sciences, Qingdao Agricultural University, Qingdao, China
| | - Xinping Zhang
- College of Food Science & Engineering, Qingdao Special Food Research Institute, Qingdao Agricultural University, Qingdao, China
- Shandong Key Lab of Applied Mycology, College of Life Sciences, Qingdao Agricultural University, Qingdao, China
| | - Chenfei Meng
- College of Food Science & Engineering, Qingdao Special Food Research Institute, Qingdao Agricultural University, Qingdao, China
- Shandong Key Lab of Applied Mycology, College of Life Sciences, Qingdao Agricultural University, Qingdao, China
| | - Lu Wang
- College of Food Science & Engineering, Qingdao Special Food Research Institute, Qingdao Agricultural University, Qingdao, China
- Shandong Key Lab of Applied Mycology, College of Life Sciences, Qingdao Agricultural University, Qingdao, China
| | - Jianming Yang
- College of Food Science & Engineering, Qingdao Special Food Research Institute, Qingdao Agricultural University, Qingdao, China.
- Shandong Key Lab of Applied Mycology, College of Life Sciences, Qingdao Agricultural University, Qingdao, China.
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9
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Peter MF, Ruland JA, Depping P, Schneberger N, Severi E, Moecking J, Gatterdam K, Tindall S, Durand A, Heinz V, Siebrasse JP, Koenig PA, Geyer M, Ziegler C, Kubitscheck U, Thomas GH, Hagelueken G. Structural and mechanistic analysis of a tripartite ATP-independent periplasmic TRAP transporter. Nat Commun 2022; 13:4471. [PMID: 35927235 PMCID: PMC9352664 DOI: 10.1038/s41467-022-31907-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2022] [Accepted: 07/08/2022] [Indexed: 11/27/2022] Open
Abstract
Tripartite ATP-independent periplasmic (TRAP) transporters are found widely in bacteria and archaea and consist of three structural domains, a soluble substrate-binding protein (P-domain), and two transmembrane domains (Q- and M-domains). HiSiaPQM and its homologs are TRAP transporters for sialic acid and are essential for host colonization by pathogenic bacteria. Here, we reconstitute HiSiaQM into lipid nanodiscs and use cryo-EM to reveal the structure of a TRAP transporter. It is composed of 16 transmembrane helices that are unexpectedly structurally related to multimeric elevator-type transporters. The idiosyncratic Q-domain of TRAP transporters enables the formation of a monomeric elevator architecture. A model of the tripartite PQM complex is experimentally validated and reveals the coupling of the substrate-binding protein to the transporter domains. We use single-molecule total internal reflection fluorescence (TIRF) microscopy in solid-supported lipid bilayers and surface plasmon resonance to study the formation of the tripartite complex and to investigate the impact of interface mutants. Furthermore, we characterize high-affinity single variable domains on heavy chain (VHH) antibodies that bind to the periplasmic side of HiSiaQM and inhibit sialic acid uptake, providing insight into how TRAP transporter function might be inhibited in vivo.
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Affiliation(s)
- Martin F Peter
- Institute of Structural Biology, University of Bonn, Venusberg-Campus 1, 53127, Bonn, Germany
| | - Jan A Ruland
- Institute for Physical und Theoretical Chemistry, University of Bonn, Wegelerstr. 12, 53127, Bonn, Germany
| | - Peer Depping
- Institute of Structural Biology, University of Bonn, Venusberg-Campus 1, 53127, Bonn, Germany
- Aston Centre for Membrane Proteins and Lipids Research, Aston St., B4 7ET, Birmingham, UK
| | - Niels Schneberger
- Institute of Structural Biology, University of Bonn, Venusberg-Campus 1, 53127, Bonn, Germany
| | - Emmanuele Severi
- Department of Biology (Area 10), University of York, York, YO10 5YW, UK
- Biosciences Institute, Newcastle University, Newcastle, NE2 4HH, UK
| | - Jonas Moecking
- Institute of Structural Biology, University of Bonn, Venusberg-Campus 1, 53127, Bonn, Germany
| | - Karl Gatterdam
- Institute of Structural Biology, University of Bonn, Venusberg-Campus 1, 53127, Bonn, Germany
| | - Sarah Tindall
- Department of Biology (Area 10), University of York, York, YO10 5YW, UK
| | - Alexandre Durand
- Institut de Génétique et de Biologie Molecule et Cellulaire, 1 Rue Laurent Fries, 67404, Illkirch Cedex, France
| | - Veronika Heinz
- Institute of Biophysics and Biophysical Chemistry, University of Regensburg, Universitätsstr. 31, 93053, Regensburg, Germany
| | - Jan Peter Siebrasse
- Institute for Physical und Theoretical Chemistry, University of Bonn, Wegelerstr. 12, 53127, Bonn, Germany
| | - Paul-Albert Koenig
- Core Facility Nanobodies, University of Bonn, Venusberg-Campus 1, 53127, Bonn, Germany
| | - Matthias Geyer
- Institute of Structural Biology, University of Bonn, Venusberg-Campus 1, 53127, Bonn, Germany
| | - Christine Ziegler
- Institute of Biophysics and Biophysical Chemistry, University of Regensburg, Universitätsstr. 31, 93053, Regensburg, Germany
| | - Ulrich Kubitscheck
- Institute for Physical und Theoretical Chemistry, University of Bonn, Wegelerstr. 12, 53127, Bonn, Germany
| | - Gavin H Thomas
- Department of Biology (Area 10), University of York, York, YO10 5YW, UK
| | - Gregor Hagelueken
- Institute of Structural Biology, University of Bonn, Venusberg-Campus 1, 53127, Bonn, Germany.
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10
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Bisson C, Salmon RC, West L, Rafferty JB, Hitchcock A, Thomas GH, Kelly DJ. The structural basis for high-affinity uptake of lignin-derived aromatic compounds by proteobacterial TRAP transporters. FEBS J 2021; 289:436-456. [PMID: 34375507 DOI: 10.1111/febs.16156] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Revised: 07/13/2021] [Accepted: 08/09/2021] [Indexed: 11/30/2022]
Abstract
The organic polymer lignin is a component of plant cell walls, which like (hemi)-cellulose is highly abundant in nature and relatively resistant to degradation. However, extracellular enzymes released by natural microbial consortia can cleave the β-aryl ether linkages in lignin, releasing monoaromatic phenylpropanoids that can be further catabolised by diverse species of bacteria. Biodegradation of lignin is therefore important in global carbon cycling, and its natural abundance also makes it an attractive biotechnological feedstock for the industrial production of commodity chemicals. Whilst the pathways for degradation of lignin-derived aromatics have been extensively characterised, much less is understood about how they are recognised and taken up from the environment. The purple phototrophic bacterium Rhodopseudomonas palustris can grow on a range of phenylpropanoid monomers and is a model organism for studying their uptake and breakdown. R. palustris encodes a tripartite ATP-independent periplasmic (TRAP) transporter (TarPQM) linked to genes encoding phenylpropanoid-degrading enzymes. The periplasmic solute-binding protein component of this transporter, TarP, has previously been shown to bind aromatic substrates. Here, we determine the high-resolution crystal structure of TarP from R. palustris as well as the structures of homologous proteins from the salt marsh bacterium Sagittula stellata and the halophile Chromohalobacter salexigens, which also grow on lignin-derived aromatics. In combination with tryptophan fluorescence ligand-binding assays, our ligand-bound co-crystal structures reveal the molecular basis for high-affinity recognition of phenylpropanoids by these TRAP transporters, which have potential for improving uptake of these compounds for biotechnological transformations of lignin.
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Affiliation(s)
- Claudine Bisson
- Department of Molecular Biology and Biotechnology, The University of Sheffield, UK
| | - Robert C Salmon
- Department of Molecular Biology and Biotechnology, The University of Sheffield, UK
| | - Laura West
- Department of Biology, University of York, UK
| | - John B Rafferty
- Department of Molecular Biology and Biotechnology, The University of Sheffield, UK
| | - Andrew Hitchcock
- Department of Molecular Biology and Biotechnology, The University of Sheffield, UK
| | | | - David J Kelly
- Department of Molecular Biology and Biotechnology, The University of Sheffield, UK
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11
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Davies JS, Currie MJ, Wright JD, Newton-Vesty MC, North RA, Mace PD, Allison JR, Dobson RCJ. Selective Nutrient Transport in Bacteria: Multicomponent Transporter Systems Reign Supreme. Front Mol Biosci 2021; 8:699222. [PMID: 34268334 PMCID: PMC8276074 DOI: 10.3389/fmolb.2021.699222] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Accepted: 06/02/2021] [Indexed: 11/24/2022] Open
Abstract
Multicomponent transporters are used by bacteria to transport a wide range of nutrients. These systems use a substrate-binding protein to bind the nutrient with high affinity and then deliver it to a membrane-bound transporter for uptake. Nutrient uptake pathways are linked to the colonisation potential and pathogenicity of bacteria in humans and may be candidates for antimicrobial targeting. Here we review current research into bacterial multicomponent transport systems, with an emphasis on the interaction at the membrane, as well as new perspectives on the role of lipids and higher oligomers in these complex systems.
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Affiliation(s)
- James S Davies
- Biomolecular Interaction Centre and School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
| | - Michael J Currie
- Biomolecular Interaction Centre and School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
| | - Joshua D Wright
- Biomolecular Interaction Centre and School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
| | - Michael C Newton-Vesty
- Biomolecular Interaction Centre and School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
| | - Rachel A North
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Peter D Mace
- Biochemistry Department, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Jane R Allison
- Maurice Wilkins Centre for Molecular Biodiscovery and School of Biological Sciences, Digital Life Institute, University of Auckland, Auckland, New Zealand
| | - Renwick C J Dobson
- Biomolecular Interaction Centre and School of Biological Sciences, University of Canterbury, Christchurch, New Zealand.,Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC, Australia
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12
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Severi E, Rudden M, Bell A, Palmer T, Juge N, Thomas GH. Multiple evolutionary origins reflect the importance of sialic acid transporters in the colonization potential of bacterial pathogens and commensals. Microb Genom 2021; 7. [PMID: 34184979 PMCID: PMC8461474 DOI: 10.1099/mgen.0.000614] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Located at the tip of cell surface glycoconjugates, sialic acids are at the forefront of host-microbe interactions and, being easily liberated by sialidase enzymes, are used as metabolites by numerous bacteria, particularly by pathogens and commensals living on or near diverse mucosal surfaces. These bacteria rely on specific transporters for the acquisition of host-derived sialic acids. Here, we present the first comprehensive genomic and phylogenetic analysis of bacterial sialic acid transporters, leading to the identification of multiple new families and subfamilies. Our phylogenetic analysis suggests that sialic acid-specific transport has evolved independently at least eight times during the evolution of bacteria, from within four of the major families/superfamilies of bacterial transporters, and we propose a robust classification scheme to bring together a myriad of different nomenclatures that exist to date. The new transporters discovered occur in diverse bacteria, including Spirochaetes, Bacteroidetes, Planctomycetes and Verrucomicrobia, many of which are species that have not been previously recognized to have sialometabolic capacities. Two subfamilies of transporters stand out in being fused to the sialic acid mutarotase enzyme, NanM, and these transporter fusions are enriched in bacteria present in gut microbial communities. Our analysis supports the increasing experimental evidence that competition for host-derived sialic acid is a key phenotype for successful colonization of complex mucosal microbiomes, such that a strong evolutionary selection has occurred for the emergence of sialic acid specificity within existing transporter architectures.
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Affiliation(s)
- Emmanuele Severi
- Department of Biology, University of York, York, UK.,Microbes in Health and Disease, Biosciences Institute, Newcastle University, Newcastle upon Tyne, UK
| | | | - Andrew Bell
- Gut Microbes and Health Institute Strategic Programme, Quadram Institute Bioscience, Norwich Research Park, Norwich, UK
| | - Tracy Palmer
- Microbes in Health and Disease, Biosciences Institute, Newcastle University, Newcastle upon Tyne, UK
| | - Nathalie Juge
- Gut Microbes and Health Institute Strategic Programme, Quadram Institute Bioscience, Norwich Research Park, Norwich, UK
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13
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Peter MF, Gebhardt C, Glaenzer J, Schneberger N, de Boer M, Thomas GH, Cordes T, Hagelueken G. Triggering Closure of a Sialic Acid TRAP Transporter Substrate Binding Protein through Binding of Natural or Artificial Substrates. J Mol Biol 2021; 433:166756. [PMID: 33316271 DOI: 10.1016/j.jmb.2020.166756] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 12/07/2020] [Accepted: 12/07/2020] [Indexed: 12/20/2022]
Abstract
The pathogens Vibrio cholerae and Haemophilus influenzae use tripartite ATP-independent periplasmic transporters (TRAPs) to scavenge sialic acid from host tissues. They use it as a nutrient or to evade the innate immune system by sialylating surface lipopolysaccharides. An essential component of TRAP transporters is a periplasmic substrate binding protein (SBP). Without substrate, the SBP has been proposed to rest in an open-state, which is not recognised by the transporter. Substrate binding induces a conformational change of the SBP and it is thought that this closed state is recognised by the transporter, triggering substrate translocation. Here we use real time single molecule FRET experiments and crystallography to investigate the open- to closed-state transition of VcSiaP, the SBP of the sialic acid TRAP transporter from V. cholerae. We show that the conformational switching of VcSiaP is strictly substrate induced, confirming an important aspect of the proposed transport mechanism. Two new crystal structures of VcSiaP provide insights into the closing mechanism. While the first structure contains the natural ligand, sialic acid, the second structure contains an artificial peptide in the sialic acid binding site. Together, the two structures suggest that the ligand itself stabilises the closed state and that SBP closure is triggered by physically bridging the gap between the two lobes of the SBP. Finally, we demonstrate that the affinity for the artificial peptide substrate can be substantially increased by varying its amino acid sequence and by this, serve as a starting point for the development of peptide-based inhibitors of TRAP transporters.
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Affiliation(s)
- Martin F Peter
- Institute of Structural Biology, University of Bonn, 53127 Bonn, Germany
| | - Christian Gebhardt
- Physical and Synthetic Biology, Faculty of Biology, Ludwig-Maximilians-Universität München, 82152 Planegg-Martinsried, Germany
| | - Janin Glaenzer
- Institute of Structural Biology, University of Bonn, 53127 Bonn, Germany
| | - Niels Schneberger
- Institute of Structural Biology, University of Bonn, 53127 Bonn, Germany
| | - Marijn de Boer
- Molecular Microscopy Research Group, Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Gavin H Thomas
- Department of Biology (Area 10), University of York, York YO10 5YW, UK
| | - Thorben Cordes
- Physical and Synthetic Biology, Faculty of Biology, Ludwig-Maximilians-Universität München, 82152 Planegg-Martinsried, Germany; Molecular Microscopy Research Group, Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Gregor Hagelueken
- Institute of Structural Biology, University of Bonn, 53127 Bonn, Germany.
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14
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Yang M, Tang Y, Weng J, Liu Z, Wang W. The Role of Calcium in Regulating the Conformational Dynamics of d-Galactose/d-Glucose-Binding Protein Revealed by Markov State Model Analysis. J Chem Inf Model 2021; 61:891-900. [PMID: 33445873 DOI: 10.1021/acs.jcim.0c01119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The d-glucose/d-galactose-binding protein (GGBP) from Escherichia coli is a substrate-binding protein (SBP) associated with sugar transport and chemotaxis. It is also a calcium-binding protein, which makes it unique in the SBP family. However, the functional importance of Ca2+ binding is not fully understood. Here, the calcium-dependent properties of GGBP were explored by all-atom molecular dynamics simulations and Markov state model (MSM) analysis as well as single-molecule Förster resonance energy transfer (smFRET) measurements. In agreement with previous experimental studies, we observed the structure stabilization effect of Ca2+ binding on the C-terminal domain of GGBP, especially the Ca2+-binding site. Interestingly, the MSMs of calcium-depleted GGBP and calcium-bound GGBP (GGBP/Ca2+) demonstrate that Ca2+ greatly stabilizes the open conformation, and smFRET measurements confirmed this result. Further analysis reveals that Ca2+ binding disturbs the local hydrogen bonding interactions and the conformational dynamics of the hinge region, thereby weakening the long-range interdomain correlations to favor the open conformation. These results suggest an active regulatory role of Ca2+ binding in GGBP, which finely tunes the conformational distribution. The work sheds new light on the study of calcium-binding proteins in prokaryotes.
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Affiliation(s)
- Maohua Yang
- Department of Chemistry, Multiscale Research Institute of Complex Systems and Institute of Biomedical Sciences, Fudan University, Shanghai 200438, China
| | - Yegen Tang
- Department of Chemistry, Multiscale Research Institute of Complex Systems and Institute of Biomedical Sciences, Fudan University, Shanghai 200438, China
| | - Jingwei Weng
- Department of Chemistry, Multiscale Research Institute of Complex Systems and Institute of Biomedical Sciences, Fudan University, Shanghai 200438, China
| | - Zhijun Liu
- National Facility for Protein Science in Shanghai, Zhangjiang Lab, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201210, China
| | - Wenning Wang
- Department of Chemistry, Multiscale Research Institute of Complex Systems and Institute of Biomedical Sciences, Fudan University, Shanghai 200438, China
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15
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Kaczmarski JA, Mahawaththa MC, Feintuch A, Clifton BE, Adams LA, Goldfarb D, Otting G, Jackson CJ. Altered conformational sampling along an evolutionary trajectory changes the catalytic activity of an enzyme. Nat Commun 2020; 11:5945. [PMID: 33230119 PMCID: PMC7683729 DOI: 10.1038/s41467-020-19695-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Accepted: 10/21/2020] [Indexed: 02/07/2023] Open
Abstract
Several enzymes are known to have evolved from non-catalytic proteins such as solute-binding proteins (SBPs). Although attention has been focused on how a binding site can evolve to become catalytic, an equally important question is: how do the structural dynamics of a binding protein change as it becomes an efficient enzyme? Here we performed a variety of experiments, including propargyl-DO3A-Gd(III) tagging and double electron-electron resonance (DEER) to study the rigid body protein dynamics of reconstructed evolutionary intermediates to determine how the conformational sampling of a protein changes along an evolutionary trajectory linking an arginine SBP to a cyclohexadienyl dehydratase (CDT). We observed that primitive dehydratases predominantly populate catalytically unproductive conformations that are vestiges of their ancestral SBP function. Non-productive conformational states, including a wide-open state, are frozen out of the conformational landscape via remote mutations, eventually leading to extant CDT that exclusively samples catalytically relevant compact states. These results show that remote mutations can reshape the global conformational landscape of an enzyme as a mechanism for increasing catalytic activity.
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Affiliation(s)
- Joe A Kaczmarski
- Research School of Chemistry, The Australian National University, Canberra, ACT, 2601, Australia
| | - Mithun C Mahawaththa
- Research School of Chemistry, The Australian National University, Canberra, ACT, 2601, Australia
| | - Akiva Feintuch
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot, 76100, Israel
| | - Ben E Clifton
- Research School of Chemistry, The Australian National University, Canberra, ACT, 2601, Australia.,Protein Engineering and Evolution Unit, Okinawa Institute of Science and Technology, 1919-1 Tancha, Onna-son, Okinawa, 904-0412, Japan
| | - Luke A Adams
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, 3052, Australia
| | - Daniella Goldfarb
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot, 76100, Israel.
| | - Gottfried Otting
- Research School of Chemistry, The Australian National University, Canberra, ACT, 2601, Australia. .,Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, Research School of Chemistry, Australian National University, Canberra, 2601, ACT, Australia.
| | - Colin J Jackson
- Research School of Chemistry, The Australian National University, Canberra, ACT, 2601, Australia. .,Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, Research School of Chemistry, Australian National University, Canberra, 2601, ACT, Australia. .,Australian Research Council Centre of Excellence in Synthetic Biology, Research School of Chemistry, Australian National University, Canberra, 2601, ACT, Australia.
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16
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Kesidis A, Depping P, Lodé A, Vaitsopoulou A, Bill RM, Goddard AD, Rothnie AJ. Expression of eukaryotic membrane proteins in eukaryotic and prokaryotic hosts. Methods 2020; 180:3-18. [DOI: 10.1016/j.ymeth.2020.06.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 06/05/2020] [Accepted: 06/08/2020] [Indexed: 12/15/2022] Open
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17
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Bell A, Severi E, Lee M, Monaco S, Latousakis D, Angulo J, Thomas GH, Naismith JH, Juge N. Uncovering a novel molecular mechanism for scavenging sialic acids in bacteria. J Biol Chem 2020; 295:13724-13736. [PMID: 32669363 PMCID: PMC7535918 DOI: 10.1074/jbc.ra120.014454] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Revised: 07/10/2020] [Indexed: 12/12/2022] Open
Abstract
The human gut symbiont Ruminococcus gnavus scavenges host-derived N-acetylneuraminic acid (Neu5Ac) from mucins by converting it to 2,7-anhydro-Neu5Ac. We previously showed that 2,7-anhydro-Neu5Ac is transported into R. gnavus ATCC 29149 before being converted back to Neu5Ac for further metabolic processing. However, the molecular mechanism leading to the conversion of 2,7-anhydro-Neu5Ac to Neu5Ac remained elusive. Using 1D and 2D NMR, we elucidated the multistep enzymatic mechanism of the oxidoreductase (RgNanOx) that leads to the reversible conversion of 2,7-anhydro-Neu5Ac to Neu5Ac through formation of a 4-keto-2-deoxy-2,3-dehydro-N-acetylneuraminic acid intermediate and NAD+ regeneration. The crystal structure of RgNanOx in complex with the NAD+ cofactor showed a protein dimer with a Rossman fold. Guided by the RgNanOx structure, we identified catalytic residues by site-directed mutagenesis. Bioinformatics analyses revealed the presence of RgNanOx homologues across Gram-negative and Gram-positive bacterial species and co-occurrence with sialic acid transporters. We showed by electrospray ionization spray MS that the Escherichia coli homologue YjhC displayed activity against 2,7-anhydro-Neu5Ac and that E. coli could catabolize 2,7-anhydro-Neu5Ac. Differential scanning fluorimetry analyses confirmed the binding of YjhC to the substrates 2,7-anhydro-Neu5Ac and Neu5Ac, as well as to co-factors NAD and NADH. Finally, using E. coli mutants and complementation growth assays, we demonstrated that 2,7-anhydro-Neu5Ac catabolism in E. coli depended on YjhC and on the predicted sialic acid transporter YjhB. These results revealed the molecular mechanisms of 2,7-anhydro-Neu5Ac catabolism across bacterial species and a novel sialic acid transport and catabolism pathway in E. coli.
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Affiliation(s)
- Andrew Bell
- Gut Microbes and Health Institute Strategic Programme, Quadram Institute Bioscience, Norwich, United Kingdom
| | | | - Micah Lee
- Division of Structural Biology, University of Oxford, Headington, Oxford, United Kingdom
| | - Serena Monaco
- School of Pharmacy, University of East Anglia, Norwich Research Park, Norwich, United Kingdom
| | - Dimitrios Latousakis
- Gut Microbes and Health Institute Strategic Programme, Quadram Institute Bioscience, Norwich, United Kingdom
| | - Jesus Angulo
- School of Pharmacy, University of East Anglia, Norwich Research Park, Norwich, United Kingdom; Departamento de Química Orgánica, Universidad de Sevilla, Sevilla, Spain; Instituto de Investigaciones Químicas (CSIC-US), Sevilla, Spain
| | - Gavin H Thomas
- Department of Biology, University of York, York, United Kingdom
| | - James H Naismith
- Division of Structural Biology, University of Oxford, Headington, Oxford, United Kingdom
| | - Nathalie Juge
- Gut Microbes and Health Institute Strategic Programme, Quadram Institute Bioscience, Norwich, United Kingdom.
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18
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Zolti A, Green SJ, Sela N, Hadar Y, Minz D. The microbiome as a biosensor: functional profiles elucidate hidden stress in hosts. MICROBIOME 2020; 8:71. [PMID: 32438915 PMCID: PMC7243336 DOI: 10.1186/s40168-020-00850-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Accepted: 04/28/2020] [Indexed: 05/10/2023]
Abstract
BACKGROUND Microbial communities are highly responsive to environmental cues, and both their structure and activity can be altered in response to changing conditions. We hypothesized that host-associated microbial communities, particularly those colonizing host surfaces, can serve as in situ sensors to reveal environmental conditions experienced by both microorganisms and the host. For a proof-of-concept, we studied a model plant-soil system and employed a non-deterministic gene-centric approach. A holistic analysis was performed using plants of two species and irrigation with water of low quality to induce host stress. Our analyses examined the genetic potential (DNA) and gene expression patterns (RNA) of plant-associated microbial communities, as well as transcriptional profiling of host plants. RESULTS Transcriptional analysis of plants irrigated with treated wastewater revealed significant enrichment of general stress-associated root transcripts relative to plants irrigated with fresh water. Metagenomic analysis of root-associated microbial communities in treated wastewater-irrigated plants, however, revealed enrichment of more specific stress-associated genes relating to high levels of salt, high pH and lower levels of oxygen. Meta-analysis of these differentially abundant genes obtained from other metagenome studies, provided evidence of the link between environmental factors such as pH and oxygen and these genes. Analysis of microbial transcriptional response demonstrated that enriched gene content was actively expressed, which implies contemporary response to elevated levels of pH and salt. CONCLUSIONS We demonstrate here that microbial profiling can elucidate stress signals that cannot be observed even through interrogation of host transcriptome, leading to an alternate mechanism for evaluating in situ conditions experienced by host organisms. This study is a proof-of-concept for the use of microbial communities as microsensors, with great potential for interrogation of a wide range of host systems. Video Abstract.
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Affiliation(s)
- Avihai Zolti
- Department of Plant Pathology and Microbiology, Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, 76100 Rehovot, Israel
- Institute of Soil, Water and Environmental Sciences, Agricultural Research Organization–Volcani Center, 7528809 Rishon Lezion, Israel
| | - Stefan J. Green
- Sequencing Core, Research Resources Center, University of Illinois at Chicago, Chicago, IL USA
| | - Noa Sela
- Institute of Soil, Water and Environmental Sciences, Agricultural Research Organization–Volcani Center, 7528809 Rishon Lezion, Israel
| | - Yitzhak Hadar
- Department of Plant Pathology and Microbiology, Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, 76100 Rehovot, Israel
| | - Dror Minz
- Institute of Soil, Water and Environmental Sciences, Agricultural Research Organization–Volcani Center, 7528809 Rishon Lezion, Israel
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19
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Elucidation of a sialic acid metabolism pathway in mucus-foraging Ruminococcus gnavus unravels mechanisms of bacterial adaptation to the gut. Nat Microbiol 2019; 4:2393-2404. [PMID: 31636419 PMCID: PMC6881182 DOI: 10.1038/s41564-019-0590-7] [Citation(s) in RCA: 70] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2019] [Accepted: 09/12/2019] [Indexed: 12/26/2022]
Abstract
Sialic acid (Neu5Ac) is commonly found in terminal location of colonic mucins glycans where it is a much-coveted nutrient for gut bacteria including Ruminococcus gnavus. R. gnavus is part of the healthy gut microbiota in humans but shows a disproportionate representation in diseases. There is therefore a need in understanding the molecular mechanisms underpinning its adaptation to the gut. Previous in vitro work demonstrated that R. gnavus mucin glycan-foraging strategy is strain-dependent and associated with the expression of an intramolecular trans-sialidase releasing 2,7-anhydro-Neu5Ac instead of Neu5Ac from mucins. Here, we have unravelled the metabolism pathway of 2,7-anhydro-Neu5Ac in R. gnavus which is underpinned by the exquisite specificity of the sialic transporter for 2,7-anhydro-Neu5Ac, and by the action of an oxidoreductase converting 2,7-anhydro-Neu5Ac into Neu5Ac which then becomes substrate of a Neu5Ac-specific aldolase. Having generated a R. gnavus nan cluster deletion mutant that lost the ability to grow on sialylated substrates, we showed that in gnotobiotic mice colonised with R. gnavus wild-type and mutant strains, the fitness of the nan mutant was significantly impaired with a reduced ability to colonise the mucus layer. Overall, our study revealed a unique sialic acid pathway in bacteria, with significant implications for the spatial adaptation of mucin-foraging gut symbionts in health and disease.
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20
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Willson BJ, Chapman LNM, Thomas GH. Evolutionary dynamics of membrane transporters and channels: enhancing function through fusion. Curr Opin Genet Dev 2019; 58-59:76-86. [DOI: 10.1016/j.gde.2019.07.017] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 07/19/2019] [Accepted: 07/23/2019] [Indexed: 02/05/2023]
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21
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Cryo-EM structure of OSCA1.2 from Oryza sativa elucidates the mechanical basis of potential membrane hyperosmolality gating. Proc Natl Acad Sci U S A 2019; 116:14309-14318. [PMID: 31227607 DOI: 10.1073/pnas.1900774116] [Citation(s) in RCA: 67] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Sensing and responding to environmental water deficiency and osmotic stresses are essential for the growth, development, and survival of plants. Recently, an osmolality-sensing ion channel called OSCA1 was discovered that functions in sensing hyperosmolality in Arabidopsis Here, we report the cryo-electron microscopy (cryo-EM) structure and function of an OSCA1 homolog from rice (Oryza sativa; OsOSCA1.2), leading to a model of how it could mediate hyperosmolality sensing and transport pathway gating. The structure reveals a dimer; the molecular architecture of each subunit consists of 11 transmembrane (TM) helices and a cytosolic soluble domain that has homology to RNA recognition proteins. The TM domain is structurally related to the TMEM16 family of calcium-dependent ion channels and lipid scramblases. The cytosolic soluble domain possesses a distinct structural feature in the form of extended intracellular helical arms that are parallel to the plasma membrane. These helical arms are well positioned to potentially sense lateral tension on the inner leaflet of the lipid bilayer caused by changes in turgor pressure. Computational dynamic analysis suggests how this domain couples to the TM portion of the molecule to open a transport pathway. Hydrogen/deuterium exchange mass spectrometry (HDXMS) experimentally confirms the conformational dynamics of these coupled domains. These studies provide a framework to understand the structural basis of proposed hyperosmolality sensing in a staple crop plant, extend our knowledge of the anoctamin superfamily important for plants and fungi, and provide a structural mechanism for potentially translating membrane stress to transport regulation.
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22
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Schäfer L, Meinert-Berning C, Wübbeler JH, Steinbüchel A. A tripartite tricarboxylate transporter (MIM_c39170-MIM_c39210) of Advenella mimigardefordensis DPN7 T is involved in citrate uptake. Int Microbiol 2019; 22:461-470. [PMID: 31098825 DOI: 10.1007/s10123-019-00073-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Revised: 03/21/2019] [Accepted: 03/22/2019] [Indexed: 01/30/2023]
Abstract
To date, tripartite tricarboxylate transport (TTT) systems are not well characterized in most organisms. To investigate which carbon sources are transported by the TTT system of A. mimigardefordensis DPN7T, single deletion mutants were generated lacking either completely both sets of genes encoding for these transport systems tctABCDE1 and tctABDE2 in the organism or the two genes encoding for the regulatory components of the third chosen TTT system, tctDE3. Deletion of tctABCDE1 (MIM_c39170-MIM_c39210) in Advenella mimigardefordensis strain DPN7T led to inhibition of growth of the cells with citrate indicating that TctABCDE1 is the transport system for the uptake of citrate. Because of the negative phenotype, it was concluded that this deletion cannot be substituted by other transporters encoded in the genome of strain DPN7T. A triple deletion mutant of A. mimigardefordensis lacking both complete TTT transport systems and the regulatory components of the third chosen system (ΔTctABCDE1 ΔTctABDE2 ΔTctDE3) showed a leaky growth with α-ketoglutarate in comparison with the wild type. The other investigated TTT (TctABDE3, MIM_c17190-MIM_c17220) is most probably involved in the transport of α-ketoglutarate. Additionally, thermoshift assays with TctC1 (MIM_c39190) showed a significant shift in the melting temperature of the protein in the presence of citrate whereas no shift occurred with α-ketoglutarate. A dissociation constant Kd for citrate of 41.7 μM was determined. Furthermore, alternative α-ketoglutarate transport was investigated via in silico analysis.
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Affiliation(s)
- Lukas Schäfer
- Institut für Molekulare Mikrobiologie und Biotechnologie, Westfälische Wilhelms-Universität Münster, 48149, Münster, Germany
| | - Christina Meinert-Berning
- Institut für Molekulare Mikrobiologie und Biotechnologie, Westfälische Wilhelms-Universität Münster, 48149, Münster, Germany
| | - Jan Hendrik Wübbeler
- Institut für Molekulare Mikrobiologie und Biotechnologie, Westfälische Wilhelms-Universität Münster, 48149, Münster, Germany
| | - Alexander Steinbüchel
- Institut für Molekulare Mikrobiologie und Biotechnologie, Westfälische Wilhelms-Universität Münster, 48149, Münster, Germany. .,Environmental Sciences Department, King Abdulaziz University, Jeddah, Saudi Arabia.
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23
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Marinelli F, Fiorin G. Structural Characterization of Biomolecules through Atomistic Simulations Guided by DEER Measurements. Structure 2019; 27:359-370.e12. [PMID: 30528595 PMCID: PMC6860373 DOI: 10.1016/j.str.2018.10.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Revised: 09/06/2018] [Accepted: 10/18/2018] [Indexed: 11/17/2022]
Abstract
Double electron-electron resonance (DEER) is a popular technique that exploits attached spin labels to probe the collective dynamics of biomolecules in a native environment. Like most spectroscopic approaches, DEER detects an ensemble of states accounting for biomolecular dynamics as well as the labels' intrinsic flexibility. Hence, the DEER data alone do not provide high-resolution structural information. To disentangle this variability, we introduce a minimally biased simulation method to sample a structural ensemble that reproduces multiple experimental signals within the uncertainty. In contrast to previous approaches, our method targets the raw data themselves, and thereby it brings forth an unbiased molecular interpretation of the experiments. After validation on the T4 lysozyme, we apply this technique to interpret recent DEER experiments on a membrane transporter binding protein (VcSiaP). The results highlight the large-scale conformational movement that occurs upon substrate binding and reveal that the unbound VcSiaP is more open in solution than the X-ray structure.
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Affiliation(s)
- Fabrizio Marinelli
- Theoretical Molecular Biophysics Laboratory, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20814, USA.
| | - Giacomo Fiorin
- Theoretical Molecular Biophysics Laboratory, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20814, USA
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24
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Rosa LT, Dix SR, Rafferty JB, Kelly DJ. A New Mechanism for High-Affinity Uptake of C4-Dicarboxylates in Bacteria Revealed by the Structure of Rhodopseudomonas palustris MatC (RPA3494), a Periplasmic Binding Protein of the Tripartite Tricarboxylate Transporter (TTT) Family. J Mol Biol 2018; 431:351-367. [PMID: 30471256 DOI: 10.1016/j.jmb.2018.11.016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Revised: 11/14/2018] [Accepted: 11/14/2018] [Indexed: 12/16/2022]
Abstract
C4-dicarboxylates play a central role in cellular physiology as key metabolic intermediates. Under aerobic conditions, they participate in the citric acid cycle, while in anaerobic bacteria, they are important in energy-conserving fermentation and respiration processes. Ten different families of secondary transporters have been described to participate in C4-dicarboxylate movement across biological membranes, but only one of these utilizes an extracytoplasmic solute binding protein to achieve high-affinity uptake. Here, we identify the MatBAC system from the photosynthetic bacterium Rhodopseudomonas palustris as the first member of the tripartite tricarboxylate transport family to be involved in C4-dicarboxylate transport. Tryptophan fluorescence spectroscopy showed that MatC, the periplasmic binding protein from this system, binds to l- and d-malate with Kd values of 27 and 21 nM, respectively, the highest reported affinity to date for these C4-dicarboxylates, and to succinate (Kd = 110 nM) and fumarate (Kd = 400 nM). The 2.1-Å crystal structure of MatC with bound malate shows a high level of substrate coordination, with participation of two water molecules that bridge hydrogen bonds between the ligand proximal carboxylic group and the main chain of two conserved loops in the protein structure. The substrate coordination in MatC correlates with the binding data and explains the protein's selectivity for different substrates and respective binding affinities. Our results reveal a new function in C4-dicarboxylate transport by members of the poorly characterized tripartite tricarboxylate transport family, which are widely distributed in bacterial genomes but for which details of structure-function relationships and transport mechanisms have been lacking.
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Affiliation(s)
- Leonardo T Rosa
- Department of Molecular Biology and Biotechnology, The University of Sheffield, Firth Court, Western Bank, Sheffield, S10 2TN, UK
| | - Samuel R Dix
- Department of Molecular Biology and Biotechnology, The University of Sheffield, Firth Court, Western Bank, Sheffield, S10 2TN, UK
| | - John B Rafferty
- Department of Molecular Biology and Biotechnology, The University of Sheffield, Firth Court, Western Bank, Sheffield, S10 2TN, UK
| | - David J Kelly
- Department of Molecular Biology and Biotechnology, The University of Sheffield, Firth Court, Western Bank, Sheffield, S10 2TN, UK.
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25
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Minhas GS, Bawdon D, Herman R, Rudden M, Stone AP, James AG, Thomas GH, Newstead S. Structural basis of malodour precursor transport in the human axilla. eLife 2018; 7:e34995. [PMID: 29966586 PMCID: PMC6059767 DOI: 10.7554/elife.34995] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Accepted: 06/23/2018] [Indexed: 01/10/2023] Open
Abstract
Mammals produce volatile odours that convey different types of societal information. In Homo sapiens, this is now recognised as body odour, a key chemical component of which is the sulphurous thioalcohol, 3-methyl-3-sulfanylhexan-1-ol (3M3SH). Volatile 3M3SH is produced in the underarm as a result of specific microbial activity, which act on the odourless dipeptide-containing malodour precursor molecule, S-Cys-Gly-3M3SH, secreted in the axilla (underarm) during colonisation. The mechanism by which these bacteria recognise S-Cys-Gly-3M3SH and produce body odour is still poorly understood. Here we report the structural and biochemical basis of bacterial transport of S-Cys-Gly-3M3SH by Staphylococcus hominis, which is converted to the sulphurous thioalcohol component 3M3SH in the bacterial cytoplasm, before being released into the environment. Knowledge of the molecular basis of precursor transport, essential for body odour formation, provides a novel opportunity to design specific inhibitors of malodour production in humans.
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Affiliation(s)
- Gurdeep S Minhas
- Department of BiochemistryUniversity of OxfordOxfordUnited Kingdom
| | - Daniel Bawdon
- Department of BiologyUniversity of YorkYorkUnited Kingdom
| | - Reyme Herman
- Department of BiologyUniversity of YorkYorkUnited Kingdom
| | | | - Andrew P Stone
- Department of BiologyUniversity of YorkYorkUnited Kingdom
| | | | - Gavin H Thomas
- Department of BiologyUniversity of YorkYorkUnited Kingdom
| | - Simon Newstead
- Department of BiochemistryUniversity of OxfordOxfordUnited Kingdom
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26
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Perturbations of erythrocyte membrane integrity by subchronic low-level lead exposure in New Zealand white rabbits. ACTA ACUST UNITED AC 2018. [DOI: 10.1007/s00580-018-2679-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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27
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Rosa LT, Bianconi ME, Thomas GH, Kelly DJ. Tripartite ATP-Independent Periplasmic (TRAP) Transporters and Tripartite Tricarboxylate Transporters (TTT): From Uptake to Pathogenicity. Front Cell Infect Microbiol 2018; 8:33. [PMID: 29479520 PMCID: PMC5812351 DOI: 10.3389/fcimb.2018.00033] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2017] [Accepted: 01/25/2018] [Indexed: 11/18/2022] Open
Abstract
The ability to efficiently scavenge nutrients in the host is essential for the viability of any pathogen. All catabolic pathways must begin with the transport of substrate from the environment through the cytoplasmic membrane, a role executed by membrane transporters. Although several classes of cytoplasmic membrane transporters are described, high-affinity uptake of substrates occurs through Solute Binding-Protein (SBP) dependent systems. Three families of SBP dependant transporters are known; the primary ATP-binding cassette (ABC) transporters, and the secondary Tripartite ATP-independent periplasmic (TRAP) transporters and Tripartite Tricarboxylate Transporters (TTT). Far less well understood than the ABC family, the TRAP transporters are found to be abundant among bacteria from marine environments, and the TTT transporters are the most abundant family of proteins in many species of β-proteobacteria. In this review, recent knowledge about these families is covered, with emphasis on their physiological and structural mechanisms, relating to several examples of relevant uptake systems in pathogenicity and colonization, using the SiaPQM sialic acid uptake system from Haemophilus influenzae and the TctCBA citrate uptake system of Salmonella typhimurium as the prototypes for the TRAP and TTT transporters, respectively. High-throughput analysis of SBPs has recently expanded considerably the range of putative substrates known for TRAP transporters, while the repertoire for the TTT family has yet to be fully explored but both types of systems most commonly transport carboxylates. Specialized spectroscopic techniques and site-directed mutagenesis have enriched our knowledge of the way TRAP binding proteins capture their substrate, while structural comparisons show conserved regions for substrate coordination in both families. Genomic and protein sequence analyses show TTT SBP genes are strikingly overrepresented in some bacteria, especially in the β-proteobacteria and some α-proteobacteria. The reasons for this are not clear but might be related to a role for these proteins in signaling rather than transport.
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Affiliation(s)
- Leonardo T Rosa
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, United Kingdom
| | - Matheus E Bianconi
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield, United Kingdom
| | - Gavin H Thomas
- Department of Biology, University of York, York, United Kingdom
| | - David J Kelly
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, United Kingdom
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28
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Li DX, Zhang H, Chen XH, Xie ZX, Zhang Y, Zhang SF, Lin L, Chen F, Wang DZ. Metaproteomics reveals major microbial players and their metabolic activities during the blooming period of a marine dinoflagellate Prorocentrum donghaiense. Environ Microbiol 2017; 20:632-644. [PMID: 29124849 DOI: 10.1111/1462-2920.13986] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Revised: 09/12/2017] [Accepted: 10/27/2017] [Indexed: 01/04/2023]
Abstract
Interactions between bacteria and phytoplankton during bloom events are essential for both partners, which impacts their physiology, alters ambient chemistry and shapes ecosystem diversity. Here, we investigated the community structure and metabolic activities of free-living bacterioplankton in different blooming phases of a dinoflagellate Prorocentrum donghaiense using a metaproteomic approach. The Fibrobacteres-Chlorobi-Bacteroidetes group, Rhodobacteraceae, SAR11 and SAR86 clades contributed largely to the bacterial community in the middle-blooming phase while the Pseudoalteromonadaceae exclusively dominated in the late-blooming phase. Transporters and membrane proteins, especially TonB-dependent receptors were highly abundant in both blooming phases. Proteins involved in carbon metabolism, energy metabolism and stress response were frequently detected in the middle-blooming phase while proteins participating in proteolysis and central carbon metabolism were abundant in the late-blooming phase. Beta-glucosidase with putative algicidal capability was identified from the Pseudoalteromonadaceae only in the late-blooming phase, suggesting an active role of this group in lysing P. donghaiense cells. Our results indicated that diverse substrate utilization strategies and different capabilities for environmental adaptation among bacteria shaped their distinct niches in different bloom phases, and certain bacterial species from the Pseudoalteromonadaceae might be crucial for the termination of a dinoflagellate bloom.
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Affiliation(s)
- Dong-Xu Li
- State Key Laboratory of Marine Environmental Science/College of the Environment and Ecology, Xiamen University, Xiamen, China
| | - Hao Zhang
- State Key Laboratory of Marine Environmental Science/College of the Environment and Ecology, Xiamen University, Xiamen, China
| | - Xiao-Huang Chen
- State Key Laboratory of Marine Environmental Science/College of the Environment and Ecology, Xiamen University, Xiamen, China
| | - Zhang-Xian Xie
- State Key Laboratory of Marine Environmental Science/College of the Environment and Ecology, Xiamen University, Xiamen, China
| | - Yong Zhang
- State Key Laboratory of Marine Environmental Science/College of the Environment and Ecology, Xiamen University, Xiamen, China
| | - Shu-Feng Zhang
- State Key Laboratory of Marine Environmental Science/College of the Environment and Ecology, Xiamen University, Xiamen, China
| | - Lin Lin
- State Key Laboratory of Marine Environmental Science/College of the Environment and Ecology, Xiamen University, Xiamen, China
| | - Feng Chen
- Institute of Marine and Environmental Technology, University of Maryland Center for Environmental Science, Baltimore, MD, USA
| | - Da-Zhi Wang
- State Key Laboratory of Marine Environmental Science/College of the Environment and Ecology, Xiamen University, Xiamen, China
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29
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Shlosman I, Marinelli F, Faraldo-Gómez JD, Mindell JA. The prokaryotic Na +/Ca 2+ exchanger NCX_Mj transports Na + and Ca 2+ in a 3:1 stoichiometry. J Gen Physiol 2017; 150:51-65. [PMID: 29237756 PMCID: PMC5749117 DOI: 10.1085/jgp.201711897] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Accepted: 11/17/2017] [Indexed: 12/17/2022] Open
Abstract
Sodium–calcium exchangers contribute to the generation of intracellular Ca2+ signals in numerous physiological processes. Shlosman et al. determine the ion stoichiometry of the only sodium–calcium exchanger of known atomic structure, revealing its functional similarity to mammalian exchangers. Intracellular Ca2+ signals control a wide array of cellular processes. These signals require spatial and temporal regulation of the intracellular Ca2+ concentration, which is achieved in part by a class of ubiquitous membrane proteins known as sodium–calcium exchangers (NCXs). NCXs are secondary-active antiporters that power the translocation of Ca2+ across the cell membrane by coupling it to the flux of Na+ in the opposite direction, down an electrochemical gradient. Na+ and Ca2+ are translocated in separate steps of the antiport cycle, each of which is thought to entail a mechanism whereby ion-binding sites within the protein become alternately exposed to either side of the membrane. The prokaryotic exchanger NCX_Mj, the only member of this family with known structure, has been proposed to be a good functional and structural model of mammalian NCXs; yet our understanding of the functional properties of this protein remains incomplete. Here, we study purified NCX_Mj reconstituted into liposomes under well-controlled experimental conditions and demonstrate that this homologue indeed shares key functional features of the NCX family. Transport assays and reversal-potential measurements enable us to delineate the essential characteristics of this antiporter and establish that its ion-exchange stoichiometry is 3Na+:1Ca2+. Together with previous studies, this work confirms that NCX_Mj is a valid model system to investigate the mechanism of ion recognition and membrane transport in sodium–calcium exchangers.
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Affiliation(s)
- Irina Shlosman
- Theoretical Molecular Biophysics Laboratory, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD.,Membrane Transport Biophysics Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD
| | - Fabrizio Marinelli
- Theoretical Molecular Biophysics Laboratory, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD
| | - José D Faraldo-Gómez
- Theoretical Molecular Biophysics Laboratory, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD
| | - Joseph A Mindell
- Membrane Transport Biophysics Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD
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30
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North RA, Horne CR, Davies JS, Remus DM, Muscroft-Taylor AC, Goyal P, Wahlgren WY, Ramaswamy S, Friemann R, Dobson RCJ. "Just a spoonful of sugar...": import of sialic acid across bacterial cell membranes. Biophys Rev 2017; 10:219-227. [PMID: 29222808 DOI: 10.1007/s12551-017-0343-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Accepted: 11/13/2017] [Indexed: 12/24/2022] Open
Abstract
Eukaryotic cell surfaces are decorated with a complex array of glycoconjugates that are usually capped with sialic acids, a large family of over 50 structurally distinct nine-carbon amino sugars, the most common member of which is N-acetylneuraminic acid. Once made available through the action of neuraminidases, bacterial pathogens and commensals utilise host-derived sialic acid by degrading it for energy or repurposing the sialic acid onto their own cell surface to camouflage the bacterium from the immune system. A functional sialic acid transporter has been shown to be essential for the uptake of sialic acid in a range of human bacterial pathogens and important for host colonisation and persistence. Here, we review the state-of-play in the field with respect to the molecular mechanisms by which these bio-nanomachines transport sialic acids across bacterial cell membranes.
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Affiliation(s)
- Rachel A North
- Biomolecular Interaction Centre and School of Biological Sciences, University of Canterbury, P.O. Box 4800, Christchurch, 8140, New Zealand
| | - Christopher R Horne
- Biomolecular Interaction Centre and School of Biological Sciences, University of Canterbury, P.O. Box 4800, Christchurch, 8140, New Zealand
| | - James S Davies
- Biomolecular Interaction Centre and School of Biological Sciences, University of Canterbury, P.O. Box 4800, Christchurch, 8140, New Zealand
| | - Daniela M Remus
- Biomolecular Interaction Centre and School of Biological Sciences, University of Canterbury, P.O. Box 4800, Christchurch, 8140, New Zealand
| | - Andrew C Muscroft-Taylor
- Biomolecular Interaction Centre and School of Biological Sciences, University of Canterbury, P.O. Box 4800, Christchurch, 8140, New Zealand
| | - Parveen Goyal
- Department of Chemistry and Molecular Biology, Biochemistry and Structural Biology, University of Gothenburg, Box 462, 40530, Gothenburg, Sweden.,Centre for Antibiotic Resistance Research (CARe) at University of Gothenburg, Box 440, 40530, Gothenburg, Sweden
| | - Weixiao Yuan Wahlgren
- Department of Chemistry and Molecular Biology, Biochemistry and Structural Biology, University of Gothenburg, Box 462, 40530, Gothenburg, Sweden.,Centre for Antibiotic Resistance Research (CARe) at University of Gothenburg, Box 440, 40530, Gothenburg, Sweden
| | - S Ramaswamy
- The Institute for Stem Cell Biology and Regenerative Medicine (InStem), G.K.V.K. Post Office, Bangalore, Karnataka, 560065, India
| | - Rosmarie Friemann
- Department of Chemistry and Molecular Biology, Biochemistry and Structural Biology, University of Gothenburg, Box 462, 40530, Gothenburg, Sweden. .,Centre for Antibiotic Resistance Research (CARe) at University of Gothenburg, Box 440, 40530, Gothenburg, Sweden.
| | - Renwick C J Dobson
- Biomolecular Interaction Centre and School of Biological Sciences, University of Canterbury, P.O. Box 4800, Christchurch, 8140, New Zealand. .,Bio21 Molecular Science and Biotechnology Institute, Department of Biochemistry and Molecular Biology, University of Melbourne, Parkville, Victoria, 3010, Australia.
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31
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Sialic acid acquisition in bacteria-one substrate, many transporters. Biochem Soc Trans 2017; 44:760-5. [PMID: 27284039 DOI: 10.1042/bst20160056] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Indexed: 11/17/2022]
Abstract
The sialic acids are a family of 9-carbon sugar acids found predominantly on the cell-surface glycans of humans and other animals within the Deuterostomes and are also used in the biology of a wide range of bacteria that often live in association with these animals. For many bacteria sialic acids are simply a convenient source of food, whereas for some pathogens they are also used in immune evasion strategies. Many bacteria that use sialic acids derive them from the environment and so are dependent on sialic acid uptake. In this mini-review I will describe the discovery and characterization of bacterial sialic acids transporters, revealing that they have evolved multiple times across multiple diverse families of transporters, including the ATP-binding cassette (ABC), tripartite ATP-independent periplasmic (TRAP), major facilitator superfamily (MFS) and sodium solute symporter (SSS) transporter families. In addition there is evidence for protein-mediated transport of sialic acids across the outer membrane of Gram negative bacteria, which can be coupled to periplasmic processing of different sialic acids to the most common form, β-D-N-acetylneuraminic acid (Neu5Ac) that is most frequently taken up into the cell.
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32
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Mulligan C, Mindell JA. Pinning Down the Mechanism of Transport: Probing the Structure and Function of Transporters Using Cysteine Cross-Linking and Site-Specific Labeling. Methods Enzymol 2017; 594:165-202. [PMID: 28779840 DOI: 10.1016/bs.mie.2017.05.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Transporters are crucial in a number of cellular functions, including nutrient uptake, cell signaling, and toxin removal. As such, transporters are important drug targets and their malfunction is related to several disease states. Treating transporter-related diseases and developing pharmaceuticals targeting transporters require an understanding of their mechanism. Achieving a detailed understanding of transporter mechanism depends on an integrative approach involving structural and computational approaches as well as biochemical and biophysical methodologies. Many of the elements of this toolkit exploit the unique and useful chemistry of the amino acid cysteine. Cysteine offers researchers a specific molecular handle with which to precisely modify the protein, which enables the introduction of biophysical probes to assess ligand binding and the conformational ensemble of the transporter, to topologically map transporters and validate structural models, and to assess essential conformational changes. Here, we summarize several uses for cysteine-based labeling and cross-linking in the pursuit of understanding transporter mechanism, the common cysteine-reactive reagents used to probe transporter mechanism, and strategies that can be used to confirm cysteine cross-link formation. In addition, we provide methodological considerations for each approach and a detailed procedure for the cross-linking of introduced cysteines, and a simple screening method to assess cross-link formation.
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Affiliation(s)
| | - Joseph A Mindell
- Membrane Transport Biophysics Section, Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, United States
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33
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Glaenzer J, Peter MF, Thomas GH, Hagelueken G. PELDOR Spectroscopy Reveals Two Defined States of a Sialic Acid TRAP Transporter SBP in Solution. Biophys J 2017; 112:109-120. [PMID: 28076802 DOI: 10.1016/j.bpj.2016.12.010] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Revised: 11/29/2016] [Accepted: 12/08/2016] [Indexed: 10/20/2022] Open
Abstract
The tripartite ATP-independent periplasmic (TRAP) transporters are a widespread class of membrane transporters in bacteria and archaea. Typical substrates for TRAP transporters are organic acids including the sialic acid N-acetylneuraminic acid. The substrate binding proteins (SBP) of TRAP transporters are the best studied component and are responsible for initial high-affinity substrate binding. To better understand the dynamics of the ligand binding process, pulsed electron-electron double resonance (PELDOR, also known as DEER) spectroscopy was applied to study the conformational changes in the N-acetylneuraminic acid-specific SBP VcSiaP. The protein is the SBP of VcSiaPQM, a sialic acid TRAP transporter from Vibrio cholerae. Spin-labeled double-cysteine mutants of VcSiaP were analyzed in the substrate-bound and -free state and the measured distances were compared to available crystal structures. The data were compatible with two clear states only, which are consistent with the open and closed forms seen in TRAP SBP crystal structures. Substrate titration experiments demonstrated the transition of the population from one state to the other with no other observed forms. Mutants of key residues involved in ligand binding and/or proposed to be involved in domain closure were produced and the corresponding PELDOR experiments reveal important insights into the open-closed transition. The results are in excellent agreement with previous in vivo sialylation experiments. The structure of the spin-labeled Q54R1/L173R1 R125A mutant was solved at 2.1 Å resolution, revealing no significant changes in the protein structure. Thus, the loss of domain closure appears to be solely due to loss of binding. In conclusion, these data are consistent with TRAP SBPs undergoing a simple two-state transition from an open-unliganded to closed-liganded state during the transport cycle.
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Affiliation(s)
- Janin Glaenzer
- Institute for Physical & Theoretical Chemistry, University of Bonn, Bonn, Germany
| | - Martin F Peter
- Institute for Physical & Theoretical Chemistry, University of Bonn, Bonn, Germany
| | | | - Gregor Hagelueken
- Institute for Physical & Theoretical Chemistry, University of Bonn, Bonn, Germany.
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Meinert C, Senger J, Witthohn M, Wübbeler JH, Steinbüchel A. Carbohydrate uptake in Advenella mimigardefordensis strain DPN7 T is mediated by periplasmic sugar oxidation and a TRAP-transport system. Mol Microbiol 2017; 104:916-930. [PMID: 28407382 DOI: 10.1111/mmi.13692] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/10/2017] [Indexed: 11/28/2022]
Abstract
In this study, we investigated an SBP (DctPAm ) of a tripartite ATP-independent periplasmic transport system (TRAP) in Advenella mimigardefordensis strain DPN7T . Deletion of dctPAm as well as of the two transmembrane compounds of the tripartite transporter, dctQ and dctM, impaired growth of A. mimigardefordensis strain DPN7T , if cultivated on mineral salt medium supplemented with d-glucose, d-galactose, l-arabinose, d-fucose, d-xylose or d-gluconic acid, respectively. The wild type phenotype was restored during complementation studies of A. mimigardefordensis ΔdctPAm using the broad host vector pBBR1MCS-5::dctPAm . Furthermore, an uptake assay with radiolabeled [14 C(U)]-d-glucose clearly showed that the deletion of dctPAm , dctQ and dctM, respectively, disabled the uptake of this aldoses in cells of either mutant strain. Determination of KD performing thermal shift assays showed a shift in the melting temperature of DctPAm in the presence of d-gluconic acid (KD 11.76 ± 1.3 µM) and the corresponding aldonic acids to the above-mentioned carbohydrates d-galactonate (KD 10.72 ± 1.4 µM), d-fuconic acid (KD 13.50 ± 1.6 µM) and d-xylonic acid (KD 8.44 ± 1.0 µM). The sugar (glucose) dehydrogenase activity (E.C.1.1.5.2) in the membrane fraction was shown for all relevant sugars, proving oxidation of the molecules in the periplasm, prior to transport.
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Affiliation(s)
- Christina Meinert
- Institut für Molekulare Mikrobiologie und Biotechnologie, Westfälische Wilhelms-Universität, Münster, D-48149, Germany
| | - Jana Senger
- Institut für Molekulare Mikrobiologie und Biotechnologie, Westfälische Wilhelms-Universität, Münster, D-48149, Germany
| | - Marco Witthohn
- Institut für Molekulare Mikrobiologie und Biotechnologie, Westfälische Wilhelms-Universität, Münster, D-48149, Germany
| | - Jan Hendrik Wübbeler
- Institut für Molekulare Mikrobiologie und Biotechnologie, Westfälische Wilhelms-Universität, Münster, D-48149, Germany
| | - Alexander Steinbüchel
- Institut für Molekulare Mikrobiologie und Biotechnologie, Westfälische Wilhelms-Universität, Münster, D-48149, Germany.,Environmental Science Department, King Abdulaziz University, Jeddah, Saudi Arabia
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Fitzgerald GA, Mulligan C, Mindell JA. A general method for determining secondary active transporter substrate stoichiometry. eLife 2017; 6. [PMID: 28121290 PMCID: PMC5305207 DOI: 10.7554/elife.21016] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2016] [Accepted: 01/17/2017] [Indexed: 12/14/2022] Open
Abstract
The number of ions required to drive substrate transport through a secondary active transporter determines the protein’s ability to create a substrate gradient, a feature essential to its physiological function, and places fundamental constraints on the transporter’s mechanism. Stoichiometry is known for a wide array of mammalian transporters, but, due to a lack of readily available tools, not for most of the prokaryotic transporters for which high-resolution structures are available. Here, we describe a general method for using radiolabeled substrate flux assays to determine coupling stoichiometries of electrogenic secondary active transporters reconstituted in proteoliposomes by measuring transporter equilibrium potentials. We demonstrate the utility of this method by determining the coupling stoichiometry of VcINDY, a bacterial Na+-coupled succinate transporter, and further validate it by confirming the coupling stoichiometry of vSGLT, a bacterial sugar transporter. This robust thermodynamic method should be especially useful in probing the mechanisms of transporters with available structures. DOI:http://dx.doi.org/10.7554/eLife.21016.001
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Affiliation(s)
- Gabriel A Fitzgerald
- Membrane Transport Biophysics Section, Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, United States
| | - Christopher Mulligan
- Membrane Transport Biophysics Section, Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, United States
| | - Joseph A Mindell
- Membrane Transport Biophysics Section, Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, United States
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36
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Jeschke G. The Making and Breaking of a Substrate Trap. Biophys J 2017; 112:1-2. [DOI: 10.1016/j.bpj.2016.12.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Accepted: 12/08/2016] [Indexed: 10/20/2022] Open
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37
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Bianchi F, Klooster JSV', Ruiz SJ, Luck K, Pols T, Urbatsch IL, Poolman B. Asymmetry in inward- and outward-affinity constant of transport explain unidirectional lysine flux in Saccharomyces cerevisiae. Sci Rep 2016; 6:31443. [PMID: 27550794 PMCID: PMC4993999 DOI: 10.1038/srep31443] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Accepted: 07/20/2016] [Indexed: 02/01/2023] Open
Abstract
The import of basic amino acids in Saccharomyces cerevisiae has been reported to be unidirectional, which is not typical of how secondary transporters work. Since studies of energy coupling and transport kinetics are complicated in vivo, we purified the major lysine transporter (Lyp1) of yeast and reconstituted the protein into lipid vesicles. We show that the Michaelis constant (KM) of transport from out-to-in is well in the millimolar range and at least 3 to 4-orders of magnitude higher than that of transport in the opposite direction, disfavoring the efflux of solute via Lyp1. We also find that at low values of the proton motive force, the transport by Lyp1 is comparatively slow. We benchmarked the properties of eukaryotic Lyp1 to that of the prokaryotic homologue LysP and find that LysP has a similar KM for transport from in-to-out and out-to-in, consistent with rapid influx and efflux. We thus explain the previously described unidirectional nature of lysine transport in S. cerevisiae by the extraordinary kinetics of Lyp1 and provide a mechanism and rationale for previous observations. The high asymmetry in transport together with secondary storage in the vacuole allow the cell to accumulate basic amino acids to very high levels.
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Affiliation(s)
- Frans Bianchi
- Department of Biochemistry, University of Groningen, Groningen Biomolecular Sciences and Biotechnology Institute, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Joury S van 't Klooster
- Department of Biochemistry, University of Groningen, Groningen Biomolecular Sciences and Biotechnology Institute, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Stephanie J Ruiz
- Department of Biochemistry, University of Groningen, Groningen Biomolecular Sciences and Biotechnology Institute, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Katja Luck
- Department of Biochemistry, University of Groningen, Groningen Biomolecular Sciences and Biotechnology Institute, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Tjeerd Pols
- Department of Biochemistry, University of Groningen, Groningen Biomolecular Sciences and Biotechnology Institute, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Ina L Urbatsch
- Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - Bert Poolman
- Department of Biochemistry, University of Groningen, Groningen Biomolecular Sciences and Biotechnology Institute, Nijenborgh 4, 9747 AG Groningen, The Netherlands.,Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
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Abstract
Sialic acids, or the more broad term nonulosonic acids, comprise a family of nine-carbon keto-sugars ubiquitous on mammalian mucous membranes as terminal modifications of mucin glycoproteins. Sialic acids have a limited distribution among bacteria, and the ability to catabolize sialic acids is mainly confined to pathogenic and commensal species. This ability to utilize sialic acid as a carbon source is correlated with bacterial virulence, especially, in the sialic acid rich environment of the oral cavity, respiratory, intestinal, and urogenital tracts. This chapter discusses the distribution of sialic acid catabolizers among the sequenced bacterial genomes and examines the studies that have linked sialic acid catabolism with increased in vivo fitness in a number of species using several animal models. This chapter presents the most recent findings in sialobiology with a focus on sialic acid catabolism, which demonstrates an important relationship between the catabolism of sialic acid and bacterial pathogenesis.
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39
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The bacterial dicarboxylate transporter VcINDY uses a two-domain elevator-type mechanism. Nat Struct Mol Biol 2016; 23:256-63. [PMID: 26828963 PMCID: PMC5215794 DOI: 10.1038/nsmb.3166] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Accepted: 12/30/2015] [Indexed: 11/11/2022]
Abstract
Secondary transporters use alternating access mechanisms to couple uphill substrate movement to downhill ion flux. Most known transporters utilize a “rocking bundle” motion, where the protein moves around an immobile substrate binding site. However, the glutamate transporter homolog, GltPh, translocates its substrate binding site vertically across the membrane, an “elevator” mechanism. Here, we used the “repeat swap” approach to computationally predict the outward-facing state of the Na+/succinate transporter VcINDY, from Vibrio cholerae. Our model predicts a substantial “elevator”-like movement of vcINDY’s substrate binding site, with a vertical translation of ~15 Å and a rotation of ~43°; multiple disulfide crosslinks which completely inhibit transport provide experimental confirmation and demonstrate that such movement is essential. In contrast, crosslinks across the VcINDY dimer interface preserve transport, revealing an absence of large scale coupling between protomers.
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40
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Fischer M, Hopkins AP, Severi E, Hawkhead J, Bawdon D, Watts AG, Hubbard RE, Thomas GH. Tripartite ATP-independent Periplasmic (TRAP) Transporters Use an Arginine-mediated Selectivity Filter for High Affinity Substrate Binding. J Biol Chem 2015; 290:27113-27123. [PMID: 26342690 PMCID: PMC4646407 DOI: 10.1074/jbc.m115.656603] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2015] [Indexed: 11/21/2022] Open
Abstract
Tripartite ATP-independent periplasmic (TRAP) transporters are secondary transporters that have evolved an obligate dependence on a substrate-binding protein (SBP) to confer unidirectional transport. Different members of the DctP family of TRAP SBPs have binding sites that recognize a diverse range of organic acid ligands but appear to only share a common electrostatic interaction between a conserved arginine and a carboxylate group in the ligand. We investigated the significance of this interaction using the sialic acid-specific SBP, SiaP, from the Haemophilus influenzae virulence-related SiaPQM TRAP transporter. Using in vitro, in vivo, and structural methods applied to SiaP, we demonstrate that the coordination of the acidic ligand moiety of sialic acid by the conserved arginine (Arg-147) is essential for the function of the transporter as a high affinity scavenging system. However, at high substrate concentrations, the transporter can function in the absence of Arg-147 suggesting that this bi-molecular interaction is not involved in further stages of the transport cycle. As well as being required for high affinity binding, we also demonstrate that the Arg-147 is a strong selectivity filter for carboxylate-containing substrates in TRAP transporters by engineering the SBP to recognize a non-carboxylate-containing substrate, sialylamide, through water-mediated interactions. Together, these data provide biochemical and structural support that TRAP transporters function predominantly as high affinity transporters for carboxylate-containing substrates.
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Affiliation(s)
- Marcus Fischer
- York Structural Biology Laboratory, Departments of Chemistry, University of York, P. O. Box 373, York YO10 5YW
| | - Adam P Hopkins
- York Structural Biology Laboratory, Departments of Biology (Area 10), University of York, P. O. Box 373, York YO10 5YW
| | - Emmanuele Severi
- York Structural Biology Laboratory, Departments of Chemistry, University of York, P. O. Box 373, York YO10 5YW
| | - Judith Hawkhead
- York Structural Biology Laboratory, Departments of Biology (Area 10), University of York, P. O. Box 373, York YO10 5YW
| | - Daniel Bawdon
- York Structural Biology Laboratory, Departments of Biology (Area 10), University of York, P. O. Box 373, York YO10 5YW
| | - Andrew G Watts
- Department of Pharmacy and Pharmacology, University of Bath, Claverton Down, Bath BA2 7AY, United Kingdom
| | - Roderick E Hubbard
- York Structural Biology Laboratory, Departments of Chemistry, University of York, P. O. Box 373, York YO10 5YW
| | - Gavin H Thomas
- York Structural Biology Laboratory, Departments of Biology (Area 10), University of York, P. O. Box 373, York YO10 5YW.
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41
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Bosdriesz E, Magnúsdóttir S, Bruggeman FJ, Teusink B, Molenaar D. Binding proteins enhance specific uptake rate by increasing the substrate-transporter encounter rate. FEBS J 2015; 282:2394-407. [PMID: 25846030 DOI: 10.1111/febs.13289] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Revised: 02/17/2015] [Accepted: 03/20/2015] [Indexed: 11/27/2022]
Abstract
Microorganisms rely on binding-protein assisted, active transport systems to scavenge for scarce nutrients. Several advantages of using binding proteins in such uptake systems have been proposed. However, a systematic, rigorous and quantitative analysis of the function of binding proteins is lacking. By combining knowledge of selection pressure and physiochemical constraints, we derive kinetic, thermodynamic, and stoichiometric properties of binding-protein dependent transport systems that enable a maximal import activity per amount of transporter. Under the hypothesis that this maximal specific activity of the transport complex is the selection objective, binding protein concentrations should exceed the concentration of both the scarce nutrient and the transporter. This increases the encounter rate of transporter with loaded binding protein at low substrate concentrations, thereby enhancing the affinity and specific uptake rate. These predictions are experimentally testable, and a number of observations confirm them.
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Affiliation(s)
- Evert Bosdriesz
- Systems Bioinformatics, VU University, Amsterdam, The Netherlands
| | | | | | - Bas Teusink
- Systems Bioinformatics, VU University, Amsterdam, The Netherlands
| | - Douwe Molenaar
- Systems Bioinformatics, VU University, Amsterdam, The Netherlands
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43
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Gangi Setty T, Cho C, Govindappa S, Apicella MA, Ramaswamy S. Bacterial periplasmic sialic acid-binding proteins exhibit a conserved binding site. ACTA CRYSTALLOGRAPHICA. SECTION D, BIOLOGICAL CRYSTALLOGRAPHY 2014; 70:1801-11. [PMID: 25004958 PMCID: PMC4089482 DOI: 10.1107/s139900471400830x] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/22/2013] [Accepted: 04/12/2014] [Indexed: 11/10/2022]
Abstract
Sialic acids are a family of related nine-carbon sugar acids that play important roles in both eukaryotes and prokaryotes. These sialic acids are incorporated/decorated onto lipooligosaccharides as terminal sugars in multiple bacteria to evade the host immune system. Many pathogenic bacteria scavenge sialic acids from their host and use them for molecular mimicry. The first step of this process is the transport of sialic acid to the cytoplasm, which often takes place using a tripartite ATP-independent transport system consisting of a periplasmic binding protein and a membrane transporter. In this paper, the structural characterization of periplasmic binding proteins from the pathogenic bacteria Fusobacterium nucleatum, Pasteurella multocida and Vibrio cholerae and their thermodynamic characterization are reported. The binding affinities of several mutations in the Neu5Ac binding site of the Haemophilus influenzae protein are also reported. The structure and the thermodynamics of the binding of sugars suggest that all of these proteins have a very well conserved binding pocket and similar binding affinities. A significant conformational change occurs when these proteins bind the sugar. While the C1 carboxylate has been identified as the primary binding site, a second conserved hydrogen-bonding network is involved in the initiation and stabilization of the conformational states.
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Affiliation(s)
- Thanuja Gangi Setty
- Institute for Stem Cell Biology and Regenerative Medicine, NCBS Campus, GKVK Post, Bangalore, Karnataka 560 065, India
| | - Christine Cho
- Department of Microbiology, Carver College of Medicine, University of Iowa, Iowa City, IA 52242-1109, USA
| | - Sowmya Govindappa
- Institute for Stem Cell Biology and Regenerative Medicine, NCBS Campus, GKVK Post, Bangalore, Karnataka 560 065, India
| | - Michael A. Apicella
- Department of Microbiology, Carver College of Medicine, University of Iowa, Iowa City, IA 52242-1109, USA
| | - S. Ramaswamy
- Institute for Stem Cell Biology and Regenerative Medicine, NCBS Campus, GKVK Post, Bangalore, Karnataka 560 065, India
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Structural and functional characterization of NanU, a novel high-affinity sialic acid-inducible binding protein of oral and gut-dwelling Bacteroidetes species. Biochem J 2014; 458:499-511. [PMID: 24351045 PMCID: PMC3969230 DOI: 10.1042/bj20131415] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Many human-dwelling bacteria acquire sialic acid for growth or surface display. We identified previously a sialic acid utilization operon in Tannerella forsythia that includes a novel outer membrane sialic acid-transport system (NanOU), where NanO (neuraminate outer membrane permease) is a putative TonB-dependent receptor and NanU (extracellular neuraminate uptake protein) is a predicted SusD family protein. Using heterologous complementation of nanOU genes into an Escherichia coli strain devoid of outer membrane sialic acid permeases, we show that the nanOU system from the gut bacterium Bacteroides fragilis is functional and demonstrate its dependence on TonB for function. We also show that nanU is required for maximal function of the transport system and that it is expressed in a sialic acid-responsive manner. We also show its cellular localization to the outer membrane using fractionation and immunofluorescence experiments. Ligand-binding studies revealed high-affinity binding of sialic acid to NanU (Kd ~400 nM) from two Bacteroidetes species as well as binding of a range of sialic acid analogues. Determination of the crystal structure of NanU revealed a monomeric SusD-like structure containing a novel motif characterized by an extended kinked helix that might determine sugar-binding specificity. The results of the present study characterize the first bacterial extracellular sialic acid-binding protein and define a sialic acid-specific PUL (polysaccharide utilization locus).
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45
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The sensor kinase DctS forms a tripartite sensor unit with DctB and DctA for sensing C4-dicarboxylates in Bacillus subtilis. J Bacteriol 2013; 196:1084-93. [PMID: 24375102 DOI: 10.1128/jb.01154-13] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
The DctSR two-component system of Bacillus subtilis controls the expression of the aerobic C4-dicarboxylate transporter DctA. Deletion of DctA leads to an increased dctA expression. The inactivation of DctB, an extracellular binding protein, is known to inhibit the expression of dctA. Here, interaction between the sensor kinase DctS and the transporter DctA as well as the binding protein DctB was demonstrated in vivo using streptavidin (Strep) or His protein interaction experiments (mSPINE or mHPINE), and the data suggest that DctA and DctB act as cosensors for DctS. The interaction between DctS and DctB was also confirmed by the bacterial two-hybrid system (BACTH). In contrast, no indication was obtained for a direct interaction between the transporter DctA and the binding protein DctB. Activity levels of uptake of [(14)C]succinate by bacteria that expressed DctA from a plasmid were similar in the absence and the presence of DctB, demonstrating that the binding protein DctB is not required for transport. Thus, DctB is involved not in transport but in cosensing with DctS, highlighting DctB as the first example of a TRAP-type binding protein that acts as a cosensor. The simultaneous presence of DctS/DctB and DctS/DctA sensor pairs and the lack of direct interaction between the cosensors DctA and DctB indicate the formation of a tripartite complex via DctS. It is suggested that the DctS/DctA/DctB complex forms the functional unit for C4-dicarboxylate sensing in B. subtilis.
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Modak A, Bhaumik P, Phale PS. Periplasmic glucose-binding protein from Pseudomonas putida CSV86--identification of the glucose-binding pocket by homology-model-guided site-specific mutagenesis. FEBS J 2013; 281:365-75. [PMID: 24206004 DOI: 10.1111/febs.12607] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2013] [Revised: 10/30/2013] [Accepted: 11/04/2013] [Indexed: 11/29/2022]
Abstract
Glucose transport in Pseudomonas putida CSV86 is mediated via a periplasmic glucose-binding protein (GBP)-dependent putative glucose ABC transporter. Here we describe a homology model and functional characterization of GBP from CSV86 (ppGBP). A whole-cell [(14)C]-glucose uptake study revealed that glucose is transported by the high-affinity intracellular phosphorylative pathway. ppGBP was cloned, over-expressed in Escherichia coli and purified to apparent homogeneity. The purified ppGBPs from both E. coli and CSV86 were found to be specific for glucose. A homology model of ppGBP was constructed that resembles the class II family of periplasmic binding proteins. The model showed highest structural similarity to GBP of Thermus thermophilus (ttGBP, rmsd 0.64 Å). Structural analysis and molecular docking studies predicted W35, W36, E41, K92, K339 and H379 of ppGBP as putative glucose-binding residues. Alanine substitution of these residues resulted in significantly reduced [(14)C]-glucose binding activity. Analysis of the operonic arrangement and structural comparative studies suggested that ppGBP and ttGBP probably originated from a common ancestor. Structural adaptations that inhibit binding of di- or trisaccharides at the glucose-binding pocket of ppGBP were also identified.
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Affiliation(s)
- Arnab Modak
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai, India
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47
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Hopkins AP, Hawkhead JA, Thomas GH. Transport and catabolism of the sialic acids N-glycolylneuraminic acid and 3-keto-3-deoxy-D-glycero-D-galactonononic acid by Escherichia coli K-12. FEMS Microbiol Lett 2013; 347:14-22. [PMID: 23848303 DOI: 10.1111/1574-6968.12213] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2013] [Revised: 06/21/2013] [Accepted: 07/05/2013] [Indexed: 11/29/2022] Open
Abstract
Escherichia coli can transport and catabolize the common sialic acid, N-acetylneuraminic acid (Neu5Ac), as a sole source of carbon and nitrogen, which is an important mucus-derived carbon source in the mammalian gut. Herein we demonstrate that E. coli can also grow efficiently on the related sialic acids, N-glycolylneuraminic acid (Neu5Gc) and 3-keto-3-deoxy-D-glycero-D-galactonononic acid (KDN), which are transported via the sialic acid transporter NanT and catabolized using the sialic acid aldolase NanA. Catabolism of Neu5Gc uses the same pathway as Neu5Ac, likely producing glycolate instead and acetate during its breakdown and catabolism of KDN requires NanA activity, while other components of the Neu5Ac catabolism pathway are non-essential. We also demonstrate that these two sialic acids can support growth of an E. coli ∆nanT strain expressing sialic acid transporters from two bacterial pathogens, namely the tripartite ATP-independent periplasmic transporter SiaPQM from Haemophilus influenzae and the sodium solute symport transporter STM1128 from Salmonella enterica ssp. Typhimurium, suggesting that the ability to use Neu5Gc and KDN in addition to Neu5Ac is present in a number of human pathogens.
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Affiliation(s)
- Adam P Hopkins
- Department of Biology, University of York, Heslington, York, UK
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48
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Salmon RC, Cliff MJ, Rafferty JB, Kelly DJ. The CouPSTU and TarPQM transporters in Rhodopseudomonas palustris: redundant, promiscuous uptake systems for lignin-derived aromatic substrates. PLoS One 2013; 8:e59844. [PMID: 23555803 PMCID: PMC3610893 DOI: 10.1371/journal.pone.0059844] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2012] [Accepted: 02/21/2013] [Indexed: 11/18/2022] Open
Abstract
The biodegradation of lignin, one of the most abundant carbon compounds on Earth, has important biotechnological applications in the derivation of useful products from lignocellulosic wastes. The purple photosynthetic bacterium Rhodopseudomonas palustris is able to grow photoheterotrophically under anaerobic conditions on a range of phenylpropeneoid lignin monomers, including coumarate, ferulate, caffeate, and cinnamate. RPA1789 (CouP) is the periplasmic binding-protein component of an ABC system (CouPSTU; RPA1789, RPA1791–1793), which has previously been implicated in the active transport of this class of aromatic substrate. Here, we show using both intrinsic tryptophan fluorescence and isothermal titration calorimetry that CouP binds a range of phenylpropeneoid ligands with Kd values in the nanomolar range. The crystal structure of CouP with ferulate as the bound ligand shows H-bond interactions between the 4-OH group of the aromatic ring with His309 and Gln305. H-bonds are also made between the carboxyl group on the ferulate side chain and Arg197, Ser222, and Thr102. An additional transport system (TarPQM; RPA1782–1784), a member of the tripartite ATP-independent periplasmic (TRAP) transporter family, is encoded at the same locus as rpa1789 and several other genes involved in coumarate metabolism. We show that the periplasmic binding-protein of this system (TarP; RPA1782) also binds coumarate, ferulate, caffeate, and cinnamate with nanomolar Kd values. Thus, we conclude that R. palustris uses two redundant but energetically distinct primary and secondary transporters that both employ high-affinity periplasmic binding-proteins to maximise the uptake of lignin-derived aromatic substrates from the environment. Our data provide a detailed thermodynamic and structural basis for understanding the interaction of lignin-derived aromatic substrates with proteins and will be of use in the further exploitation of the flexible metabolism of R. palustris for anaerobic aromatic biotransformations.
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Affiliation(s)
- Robert C. Salmon
- Department of Molecular Biology and Biotechnology, The University of Sheffield, Sheffield, United Kingdom
| | - Matthew J. Cliff
- Manchester Institute of Biotechnology, The University of Manchester, Manchester, United Kingdom
| | - John B. Rafferty
- Department of Molecular Biology and Biotechnology, The University of Sheffield, Sheffield, United Kingdom
- * E-mail: (JR); (DJK)
| | - David J. Kelly
- Department of Molecular Biology and Biotechnology, The University of Sheffield, Sheffield, United Kingdom
- * E-mail: (JR); (DJK)
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Anba-Mondoloni J, Chaillou S, Zagorec M, Champomier-Vergès MC. Catabolism of N-acetylneuraminic acid, a fitness function of the food-borne lactic acid bacterium Lactobacillus sakei, involves two newly characterized proteins. Appl Environ Microbiol 2013; 79:2012-8. [PMID: 23335758 PMCID: PMC3592224 DOI: 10.1128/aem.03301-12] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2012] [Accepted: 01/11/2013] [Indexed: 01/27/2023] Open
Abstract
In silico analysis of the genome sequence of the meat-borne lactic acid bacterium (LAB) Lactobacillus sakei 23K has revealed a repertoire of potential functions related to the adaptation of this bacterium to the meat environment. Among these functions, the ability to use N-acetyl-neuraminic acid (NANA) as a carbon source could provide a competitive advantage for growth on meat in which this amino sugar is present. In this work, we proposed to analyze the functionality of a gene cluster encompassing nanTEAR and nanK (nanTEAR-nanK). We established that this cluster encoded a pathway allowing transport and early steps of the catabolism of NANA in this genome. We also demonstrated that this cluster was absent from the genome of other L. sakei strains that were shown to be unable to grow on NANA. Moreover, L. sakei 23K nanA, nanT, nanK, and nanE genes were able to complement Escherichia coli mutants. Construction of different mutants in L. sakei 23K ΔnanR, ΔnanT, and ΔnanK and the double mutant L. sakei 23K Δ(nanA-nanE) made it possible to show that all were impaired for growth on NANA. In addition, two genes located downstream from nanK, lsa1644 and lsa1645, are involved in the catabolism of sialic acid in L. sakei 23K, as a L. sakei 23K Δlsa1645 mutant was no longer able to grow on NANA. All these results demonstrate that the gene cluster nanTEAR-nanK-lsa1644-lsa1645 is indeed involved in the use of NANA as an energy source by L. sakei.
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50
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Gruteser N, Marin K, Krämer R, Thomas GH. Sialic acid utilization by the soil bacterium Corynebacterium glutamicum. FEMS Microbiol Lett 2012; 336:131-8. [PMID: 22924979 DOI: 10.1111/j.1574-6968.2012.02663.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2012] [Revised: 08/20/2012] [Accepted: 08/21/2012] [Indexed: 11/28/2022] Open
Abstract
The ability to use the sialic acid, N-acetylneuraminic acid, Neu5Ac, as a nutrient has been characterized in a number of bacteria, most of which are human pathogens that encounter this molecule because of its presence on mucosal surfaces. The soil bacterium Corynebacterium glutamicum also has a full complement of genes for sialic acid catabolism, and we demonstrate that it can use Neu5Ac as a sole source of carbon and energy and isolate mutants with a much reduced growth lag on Neu5Ac. Disruption of the cg2937 gene, encoding a component of a predicted sialic acid-specific ABC transporter, results in a complete loss of growth of C. glutamicum on Neu5Ac and also a complete loss of [(14)C]-Neu5Ac uptake into cells. Uptake of [(14)C]-Neu5Ac is induced by pregrowth on Neu5Ac, but the additional presence of glucose prevents this induction. The demonstration that a member of the Actinobacteria can transport and catabolize Neu5Ac efficiently suggests that sialic acid metabolism has a physiological role in the soil environment.
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Affiliation(s)
- Nadine Gruteser
- Department of Biology (Area 10), University of York, York, UK
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