1
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Partipilo M, Jan Slotboom D. The S-component fold: a link between bacterial transporters and receptors. Commun Biol 2024; 7:610. [PMID: 38773269 PMCID: PMC11109136 DOI: 10.1038/s42003-024-06295-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Accepted: 05/06/2024] [Indexed: 05/23/2024] Open
Abstract
The processes of nutrient uptake and signal sensing are crucial for microbial survival and adaptation. Membrane-embedded proteins involved in these functions (transporters and receptors) are commonly regarded as unrelated in terms of sequence, structure, mechanism of action and evolutionary history. Here, we analyze the protein structural universe using recently developed artificial intelligence-based structure prediction tools, and find an unexpected link between prominent groups of microbial transporters and receptors. The so-called S-components of Energy-Coupling Factor (ECF) transporters, and the membrane domains of sensor histidine kinases of the 5TMR cluster share a structural fold. The discovery of their relatedness manifests a widespread case of prokaryotic "transceptors" (related proteins with transport or receptor function), showcases how artificial intelligence-based structure predictions reveal unchartered evolutionary connections between proteins, and provides new avenues for engineering transport and signaling functions in bacteria.
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Affiliation(s)
- Michele Partipilo
- Department of Biochemistry, Groningen Institute of Biomolecular Sciences & Biotechnology, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, The Netherlands
| | - Dirk Jan Slotboom
- Department of Biochemistry, Groningen Institute of Biomolecular Sciences & Biotechnology, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, The Netherlands.
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2
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Nijland M, Lefebvre SN, Thangaratnarajah C, Slotboom DJ. Bidirectional ATP-driven transport of cobalamin by the mycobacterial ABC transporter BacA. Nat Commun 2024; 15:2626. [PMID: 38521790 PMCID: PMC10960864 DOI: 10.1038/s41467-024-46917-1] [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: 10/13/2023] [Accepted: 03/13/2024] [Indexed: 03/25/2024] Open
Abstract
BacA is a mycobacterial ATP-binding cassette (ABC) transporter involved in the translocation of water-soluble compounds across the lipid bilayer. Whole-cell-based assays have shown that BacA imports cobalamin as well as unrelated hydrophilic compounds such as the antibiotic bleomycin and the antimicrobial peptide Bac7 into the cytoplasm. Surprisingly, there are indications that BacA also mediates the export of different antibacterial compounds, which is difficult to reconcile with the notion that ABC transporters generally operate in a strictly unidirectional manner. Here we resolve this conundrum by developing a fluorescence-based transport assay to monitor the transport of cobalamin across liposomal membranes. We find that BacA transports cobalamin in both the import and export direction. This highly unusual bidirectionality suggests that BacA is mechanistically distinct from other ABC transporters and facilitates ATP-driven diffusion, a function that may be important for the evolvability of specific transporters, and may bring competitive advantages to microbial communities.
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Affiliation(s)
- Mark Nijland
- Faculty of Science and Engineering, Groningen, Biomolecular Sciences and Biotechnology, Membrane Enzymology Group, University of Groningen, 9747 AG, Groningen, The Netherlands
| | - Solène N Lefebvre
- Faculty of Science and Engineering, Groningen, Biomolecular Sciences and Biotechnology, Membrane Enzymology Group, University of Groningen, 9747 AG, Groningen, The Netherlands
| | - Chancievan Thangaratnarajah
- Faculty of Science and Engineering, Groningen, Biomolecular Sciences and Biotechnology, Membrane Enzymology Group, University of Groningen, 9747 AG, Groningen, The Netherlands
- Sosei Heptares, Steinmetz Building, Granta Park, Great Abington, Cambridge, CB21 6DG, UK
| | - Dirk J Slotboom
- Faculty of Science and Engineering, Groningen, Biomolecular Sciences and Biotechnology, Membrane Enzymology Group, University of Groningen, 9747 AG, Groningen, The Netherlands.
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3
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Exapicheidou IA, Shams A, Ibrahim H, Tsarenko A, Backenköhler M, Hamed MM, Diamanti E, Volkamer A, Slotboom DJ, Hirsch AKH. Hit optimization by dynamic combinatorial chemistry on Streptococcus pneumoniae energy-coupling factor transporter ECF-PanT. Chem Commun (Camb) 2024; 60:870-873. [PMID: 38164786 DOI: 10.1039/d3cc04738e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2024]
Abstract
Herein, we present the first application of target-directed dynamic combinatorial chemistry (tdDCC) to the whole complex of the highly dynamic transmembrane, energy-coupling factor (ECF) transporter ECF-PanT in Streptococcus pneumoniae. In addition, we successfully employed the tdDCC technique as a hit-identification and -optimization strategy that led to the identification of optimized ECF inhibitors with improved activity. We characterized the best compounds regarding cytotoxicity and performed computational modeling studies on the crystal structure of ECF-PanT to rationalize their binding mode. Notably, docking studies showed that the acylhydrazone linker is able to maintain the crucial interactions.
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Affiliation(s)
- Ioulia Antonia Exapicheidou
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS) - Helmholtz Centre for Infection Research (HZI), 66123, Saarbrücken, Germany.
- Saarland University, Department of Pharmacy, Campus Building E8.1, 66123, Saarbrücken, Germany
| | - Atanaz Shams
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS) - Helmholtz Centre for Infection Research (HZI), 66123, Saarbrücken, Germany.
- Saarland University, Department of Pharmacy, Campus Building E8.1, 66123, Saarbrücken, Germany
| | - Hamza Ibrahim
- Data Driven Drug Design Group, Center for Bioinformatics, Saarland Informatics Campus E2.1, Saarland University, Saarbrücken 66123, Germany
| | - Aleksei Tsarenko
- Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 4, 9747, AG, Groningen, The Netherlands
| | - Michael Backenköhler
- Data Driven Drug Design Group, Center for Bioinformatics, Saarland Informatics Campus E2.1, Saarland University, Saarbrücken 66123, Germany
| | - Mostafa M Hamed
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS) - Helmholtz Centre for Infection Research (HZI), 66123, Saarbrücken, Germany.
| | - Eleonora Diamanti
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS) - Helmholtz Centre for Infection Research (HZI), 66123, Saarbrücken, Germany.
| | - Andrea Volkamer
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS) - Helmholtz Centre for Infection Research (HZI), 66123, Saarbrücken, Germany.
- Data Driven Drug Design Group, Center for Bioinformatics, Saarland Informatics Campus E2.1, Saarland University, Saarbrücken 66123, Germany
| | - Dirk J Slotboom
- Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 4, 9747, AG, Groningen, The Netherlands
| | - Anna K H Hirsch
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS) - Helmholtz Centre for Infection Research (HZI), 66123, Saarbrücken, Germany.
- Saarland University, Department of Pharmacy, Campus Building E8.1, 66123, Saarbrücken, Germany
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4
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Diamanti E, Souza PCT, Setyawati I, Bousis S, Monjas L, Swier LJYM, Shams A, Tsarenko A, Stanek WK, Jäger M, Marrink SJ, Slotboom DJ, Hirsch AKH. Identification of inhibitors targeting the energy-coupling factor (ECF) transporters. Commun Biol 2023; 6:1182. [PMID: 37985798 PMCID: PMC10662466 DOI: 10.1038/s42003-023-05555-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Accepted: 11/08/2023] [Indexed: 11/22/2023] Open
Abstract
The energy-coupling factor (ECF) transporters are a family of transmembrane proteins involved in the uptake of vitamins in a wide range of bacteria. Inhibition of the activity of these proteins could reduce the viability of pathogens that depend on vitamin uptake. The central role of vitamin transport in the metabolism of bacteria and absence from humans make the ECF transporters an attractive target for inhibition with selective chemical probes. Here, we report on the identification of a promising class of inhibitors of the ECF transporters. We used coarse-grained molecular dynamics simulations on Lactobacillus delbrueckii ECF-FolT2 and ECF-PanT to profile the binding mode and mechanism of inhibition of this novel chemotype. The results corroborate the postulated mechanism of transport and pave the way for further drug-discovery efforts.
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Affiliation(s)
- Eleonora Diamanti
- Helmholtz Institute for Pharmaceutical Research (HIPS) - Helmholtz Centre for Infection Research (HZI), Campus Building E 8.1, D-66123, Saarbrücken, Germany
| | - Paulo C T Souza
- Molecular Microbiology and Structural Biochemistry, UMR 5086 CNRS and University of Lyon, Lyon, France
- Laboratoire de Biologie et Modélisation de la Cellule (UMR 5239, Inserm, U1293) and Centre Blaise Pascal, École Normale Supérieure de Lyon, Université Claude Bernard Lyon 1 and CNRS, 46 Allée d'Italie, 69007, Lyon, France
| | - Inda Setyawati
- Biomolecular Sciences and Biotechnology Institute University of Groningen Nijenborgh 4, 9747AG, Groningen, The Netherlands
- Department of Biochemistry, Bogor Agricultural University, Dramaga, 16680, Bogor, Indonesia
| | - Spyridon Bousis
- Helmholtz Institute for Pharmaceutical Research (HIPS) - Helmholtz Centre for Infection Research (HZI), Campus Building E 8.1, D-66123, Saarbrücken, Germany
- Department of Pharmacy, Saarland University, Campus Building E8.1, 66123, Saarbrücken, Germany
- Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 7, NL-9747, AG Groningen, the Netherlands
| | - Leticia Monjas
- Department of Pharmacy, Saarland University, Campus Building E8.1, 66123, Saarbrücken, Germany
| | - Lotteke J Y M Swier
- Biomolecular Sciences and Biotechnology Institute University of Groningen Nijenborgh 4, 9747AG, Groningen, The Netherlands
| | - Atanaz Shams
- Helmholtz Institute for Pharmaceutical Research (HIPS) - Helmholtz Centre for Infection Research (HZI), Campus Building E 8.1, D-66123, Saarbrücken, Germany
| | - Aleksei Tsarenko
- Biomolecular Sciences and Biotechnology Institute University of Groningen Nijenborgh 4, 9747AG, Groningen, The Netherlands
| | - Weronika K Stanek
- Biomolecular Sciences and Biotechnology Institute University of Groningen Nijenborgh 4, 9747AG, Groningen, The Netherlands
| | - Manuel Jäger
- Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 7, NL-9747, AG Groningen, the Netherlands
| | - Siewert J Marrink
- Biomolecular Sciences and Biotechnology Institute University of Groningen Nijenborgh 4, 9747AG, Groningen, The Netherlands
| | - Dirk J Slotboom
- Biomolecular Sciences and Biotechnology Institute University of Groningen Nijenborgh 4, 9747AG, Groningen, The Netherlands
| | - Anna K H Hirsch
- Helmholtz Institute for Pharmaceutical Research (HIPS) - Helmholtz Centre for Infection Research (HZI), Campus Building E 8.1, D-66123, Saarbrücken, Germany.
- Department of Pharmacy, Saarland University, Campus Building E8.1, 66123, Saarbrücken, Germany.
- Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 7, NL-9747, AG Groningen, the Netherlands.
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5
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Kristensen SS, Lukassen MV, Siebenhaar S, Diep DB, Morth JP, Mathiesen G. Lactiplantibacillus plantarum as a novel platform for production and purification of integral membrane proteins using RseP as the benchmark. Sci Rep 2023; 13:14361. [PMID: 37658186 PMCID: PMC10474122 DOI: 10.1038/s41598-023-41559-7] [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: 03/06/2023] [Accepted: 08/28/2023] [Indexed: 09/03/2023] Open
Abstract
The present study describes a detailed procedure for expressing and purifying the integral membrane protein RseP using the pSIP system and Lactiplantibacillus plantarum as an expression host. RseP is a membrane-bound site-2-protease and a known antibacterial target in multiple human pathogens. In the present study, we screened five RseP orthologs from Gram-positive bacteria and found RseP from Enterococcus faecium (EfmRseP) to yield the highest protein levels. The production conditions were optimized and EfmRseP was purified by immobilized metal ion affinity chromatography followed by size-exclusion chromatography. The purification resulted in an overall yield of approximately 1 mg of pure protein per 3 g of wet-weight cell pellet. The structural integrity of the purified protein was confirmed using circular dichroism. We further assessed the expression and purification of RseP from E. faecium in the Gram-negative Escherichia coli. Detection of soluble protein failed in two of the three E. coli strains tested. Purification of EfmRseP expressed in E. coli C43(DE3) resulted in a protein with lower purity compared to EfmRseP expressed in L. plantarum. To our knowledge, this is the first time L. plantarum and the pSIP expression system have been applied for the production of membrane proteins.
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Affiliation(s)
- Sofie S Kristensen
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), Ås, Norway.
| | - Marie V Lukassen
- Department of Biotechnology and Biomedicine, Technical University of Denmark (DTU), Kongens Lyngby, Denmark
| | - Suzana Siebenhaar
- Department of Biotechnology and Biomedicine, Technical University of Denmark (DTU), Kongens Lyngby, Denmark
| | - Dzung B Diep
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), Ås, Norway
| | - J Preben Morth
- Department of Biotechnology and Biomedicine, Technical University of Denmark (DTU), Kongens Lyngby, Denmark.
| | - Geir Mathiesen
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), Ås, Norway.
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6
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Thangaratnarajah C, Nijland M, Borges-Araújo L, Jeucken A, Rheinberger J, Marrink SJ, Souza PCT, Paulino C, Slotboom DJ. Expulsion mechanism of the substrate-translocating subunit in ECF transporters. Nat Commun 2023; 14:4484. [PMID: 37491368 PMCID: PMC10368641 DOI: 10.1038/s41467-023-40266-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Accepted: 07/20/2023] [Indexed: 07/27/2023] Open
Abstract
Energy-coupling factor (ECF)-type transporters mediate the uptake of micronutrients in many bacteria. They consist of a substrate-translocating subunit (S-component) and an ATP-hydrolysing motor (ECF module) Previous data indicate that the S-component topples within the membrane to alternately expose the binding site to either side of the membrane. In many ECF transporters, the substrate-free S-component can be expelled from the ECF module. Here we study this enigmatic expulsion step by cryogenic electron microscopy and reveal that ATP induces a concave-to-convex shape change of two long helices in the motor, thereby destroying the S-component's docking site and allowing for its dissociation. We show that adaptation of the membrane morphology to the conformational state of the motor may favour expulsion of the substrate-free S-component when ATP is bound and docking of the substrate-loaded S-component after hydrolysis. Our work provides a picture of bilayer-assisted chemo-mechanical coupling in the transport cycle of ECF transporters.
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Affiliation(s)
- Chancievan Thangaratnarajah
- Faculty of Science and Engineering, Groningen Biomolecular Sciences and Biotechnology, Membrane Enzymology Group, University of Groningen, 9747 AG, Groningen, The Netherlands
- Faculty of Science and Engineering, Groningen Biomolecular Sciences and Biotechnology, Electron Microscopy Group, University of Groningen, 9747 AG, Groningen, The Netherlands
| | - Mark Nijland
- Faculty of Science and Engineering, Groningen Biomolecular Sciences and Biotechnology, Membrane Enzymology Group, University of Groningen, 9747 AG, Groningen, The Netherlands
| | - Luís Borges-Araújo
- Molecular Microbiology and Structural Biochemistry, CNRS and University of Lyon, 69367, Lyon, France
| | - Aike Jeucken
- Faculty of Science and Engineering, Groningen Biomolecular Sciences and Biotechnology, Membrane Enzymology Group, University of Groningen, 9747 AG, Groningen, The Netherlands
| | - Jan Rheinberger
- Faculty of Science and Engineering, Groningen Biomolecular Sciences and Biotechnology, Membrane Enzymology Group, University of Groningen, 9747 AG, Groningen, The Netherlands
- Faculty of Science and Engineering, Groningen Biomolecular Sciences and Biotechnology, Electron Microscopy Group, University of Groningen, 9747 AG, Groningen, The Netherlands
- Biochemistry Center, University of Heidelberg, Im Neuenheimer Feld 328, 69120, Heidelberg, Germany
| | - Siewert J Marrink
- Faculty of Science and Engineering, Groningen Biomolecular Sciences and Biotechnology, Molecular Dynamics Group, University of Groningen, 9747 AG, Groningen, The Netherlands
| | - Paulo C T Souza
- Molecular Microbiology and Structural Biochemistry, CNRS and University of Lyon, 69367, Lyon, France
| | - Cristina Paulino
- Faculty of Science and Engineering, Groningen Biomolecular Sciences and Biotechnology, Membrane Enzymology Group, University of Groningen, 9747 AG, Groningen, The Netherlands.
- Faculty of Science and Engineering, Groningen Biomolecular Sciences and Biotechnology, Electron Microscopy Group, University of Groningen, 9747 AG, Groningen, The Netherlands.
- Biochemistry Center, University of Heidelberg, Im Neuenheimer Feld 328, 69120, Heidelberg, Germany.
| | - Dirk J Slotboom
- Faculty of Science and Engineering, Groningen Biomolecular Sciences and Biotechnology, Membrane Enzymology Group, University of Groningen, 9747 AG, Groningen, The Netherlands.
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7
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Rivera-Lugo R, Huang S, Lee F, Méheust R, Iavarone AT, Sidebottom AM, Oldfield E, Portnoy DA, Light SH. Distinct Energy-Coupling Factor Transporter Subunits Enable Flavin Acquisition and Extracytosolic Trafficking for Extracellular Electron Transfer in Listeria monocytogenes. mBio 2023; 14:e0308522. [PMID: 36744898 PMCID: PMC9973259 DOI: 10.1128/mbio.03085-22] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Accepted: 01/05/2023] [Indexed: 02/07/2023] Open
Abstract
A variety of electron transfer mechanisms link bacterial cytosolic electron pools with functionally diverse redox activities in the cell envelope and extracellular space. In Listeria monocytogenes, the ApbE-like enzyme FmnB catalyzes extracytosolic protein flavinylation, covalently linking a flavin cofactor to proteins that transfer electrons to extracellular acceptors. L. monocytogenes uses an energy-coupling factor (ECF) transporter complex that contains distinct substrate-binding, transmembrane, ATPase A, and ATPase A' subunits (RibU, EcfT, EcfA, and EcfA') to import environmental flavins, but the basis of extracytosolic flavin trafficking for FmnB flavinylation remains poorly defined. In this study, we show that the EetB and FmnA proteins are related to ECF transporter substrate-binding and transmembrane subunits, respectively, and are essential for exporting flavins from the cytosol for flavinylation. Comparisons of the flavin import versus export capabilities of L. monocytogenes strains lacking different ECF transporter subunits demonstrate a strict directionality of substrate-binding subunit transport but partial functional redundancy of transmembrane and ATPase subunits. Based on these results, we propose that ECF transporter complexes with different subunit compositions execute directional flavin import/export through a broadly conserved mechanism. Finally, we present genomic context analyses that show that related ECF exporter genes are distributed across members of the phylum Firmicutes and frequently colocalize with genes encoding flavinylated extracytosolic proteins. These findings clarify the basis of ECF transporter export and extracytosolic flavin cofactor trafficking in Firmicutes. IMPORTANCE Bacteria import vitamins and other essential compounds from their surroundings but also traffic related compounds from the cytosol to the cell envelope where they serve various functions. Studying the foodborne pathogen Listeria monocytogenes, we find that the modular use of subunits from a prominent class of bacterial transporters enables the import of environmental vitamin B2 cofactors and the extracytosolic trafficking of a vitamin B2-derived cofactor that facilitates redox reactions in the cell envelope. These studies clarify the basis of bidirectional small-molecule transport across the cytoplasmic membrane and the assembly of redox-active proteins within the cell envelope and extracellular space.
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Affiliation(s)
- Rafael Rivera-Lugo
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California, USA
| | - Shuo Huang
- Duchossois Family Institute, University of Chicago, Chicago, Illinois, USA
- Department of Microbiology, University of Chicago, Chicago, Illinois, USA
| | - Frank Lee
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, California, USA
| | - Raphaël Méheust
- Génomique Métabolique, CEA, Genoscope, Institut François Jacob, Université d’Évry, Université Paris-Saclay, CNRS, Evry, France
| | - Anthony T. Iavarone
- QB3/Chemistry Mass Spectrometry Facility, University of California, Berkeley, Berkeley, California, USA
| | | | - Eric Oldfield
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Daniel A. Portnoy
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California, USA
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, California, USA
| | - Samuel H. Light
- Duchossois Family Institute, University of Chicago, Chicago, Illinois, USA
- Department of Microbiology, University of Chicago, Chicago, Illinois, USA
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8
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Zhang Q, Kong L, Wang Q, Wang H, Yang Y, Fu J, Zhang Y, Dong J, Zeng C, Liu H. A biotin-stabilized HKUST-1/ADM scaffold for facilitating MSC endothelial differentiation and vascularization in diabetic wound healing. Biomater Sci 2023; 11:854-872. [PMID: 36515094 DOI: 10.1039/d2bm01443b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Inadequate angiogenesis in diabetic wound healing has been identified as one of the most difficult issues to treat. Copper ions (Cu2+) have been confirmed to stimulate angiogenesis; nevertheless, the rapid rise in non-physiological Cu2+ concentrations increases the danger of ion poisoning. For the first time, biotin was used to stabilize a copper-based metal-organic framework (HKUST-1) to change its hydrophobicity and achieve sustained release of Cu2+. The inability to offer a suitable area for the dynamic interaction between cells and growth factors still restricts the use of nanomaterials for the regeneration of injured skin in diabetes. Acellular dermal matrix (ADM) scaffolds are collagen fibers with natural spatial tissue that can create a biological "niche" for cell attachment and growth. In this study, biotin-stabilized HKUST-1 (B-HKUST-1) nanoparticles were modified with an ADM to form a novel scaffold (ADM-B-HKUST-1). Notably, Cu2+ and mesenchymal stem cells (MSCs) released by the composite scaffold may synergistically promote MSC adhesion, proliferation and endothelial differentiation by upregulating the expression of transforming growth factor-β (TGF-β), vascular endothelial growth factor (VEGF) and alpha-smooth muscle actin (α-SMA). Overall, the ADM-B-HKUST1 scaffold combines the dual advantages of the sustained release of Cu2+ and creating a biological "niche" can provide a potential strategy for enhancing angiogenesis and promoting diabetic wound healing.
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Affiliation(s)
- Qiong Zhang
- MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou 510631, China.
| | - Linghong Kong
- MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou 510631, China.
| | - Qi Wang
- MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou 510631, China.
| | - Hui Wang
- MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou 510631, China.
| | - Yongzhen Yang
- MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou 510631, China.
| | - Jinping Fu
- MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou 510631, China.
| | - Yue Zhang
- MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou 510631, China.
| | - Jianyue Dong
- MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou 510631, China.
| | - Changchun Zeng
- Department of Medical Laboratory, Shenzhen Longhua District Central Hospital, Guangdong Medical University, Shenzhen, 518110, China.,Department of General Medicine, Shenzhen Longhua District Central Hospital, Shenzhen 518110, China.
| | - Hanping Liu
- MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou 510631, China.
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9
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Kiefer AF, Bousis S, Hamed MM, Diamanti E, Haupenthal J, Hirsch AKH. Structure-Guided Optimization of Small-Molecule Folate Uptake Inhibitors Targeting the Energy-Coupling Factor Transporters. J Med Chem 2022; 65:8869-8880. [PMID: 35709475 PMCID: PMC9289886 DOI: 10.1021/acs.jmedchem.1c02114] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
![]()
Here, we report on
a potent class of substituted ureidothiophenes
targeting energy-coupling factor (ECF) transporters, an unexplored
target that is not addressed by any antibiotic in the market. Since
the ECF module is crucial for the vitamin transport mechanism, the
prevention of substrate uptake should ultimately lead to cell death.
By utilizing a combination of virtual and functional whole-cell screening
of our in-house library, the membrane-bound protein mediated uptake
of folate could be effectively inhibited. Structure-based optimization
of our hit yielded low-micromolar inhibitors, whereby the most active
compounds showed in addition potent antimicrobial activities against
a panel of clinically relevant Gram-positive pathogens without significant
cytotoxic effects.
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Affiliation(s)
- Alexander F Kiefer
- Helmholtz-Institute for Pharmaceutical Research Saarland (HIPS)-Helmholtz Centre for Infection Research (HZI), Campus E8.1, 66123 Saarbrücken, Germany
| | - Spyridon Bousis
- Helmholtz-Institute for Pharmaceutical Research Saarland (HIPS)-Helmholtz Centre for Infection Research (HZI), Campus E8.1, 66123 Saarbrücken, Germany.,Department of Pharmacy, Saarland University, Campus E8.1, 66123 Saarbrücken, Germany
| | - Mostafa M Hamed
- Helmholtz-Institute for Pharmaceutical Research Saarland (HIPS)-Helmholtz Centre for Infection Research (HZI), Campus E8.1, 66123 Saarbrücken, Germany
| | - Eleonora Diamanti
- Helmholtz-Institute for Pharmaceutical Research Saarland (HIPS)-Helmholtz Centre for Infection Research (HZI), Campus E8.1, 66123 Saarbrücken, Germany.,Helmholtz International Lab for Anti-Infectives, Campus E8.1, 66123 Saarbrücken, Germany
| | - Jörg Haupenthal
- Helmholtz-Institute for Pharmaceutical Research Saarland (HIPS)-Helmholtz Centre for Infection Research (HZI), Campus E8.1, 66123 Saarbrücken, Germany
| | - Anna K H Hirsch
- Helmholtz-Institute for Pharmaceutical Research Saarland (HIPS)-Helmholtz Centre for Infection Research (HZI), Campus E8.1, 66123 Saarbrücken, Germany.,Department of Pharmacy, Saarland University, Campus E8.1, 66123 Saarbrücken, Germany.,Helmholtz International Lab for Anti-Infectives, Campus E8.1, 66123 Saarbrücken, Germany
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10
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Newstead S. Structural basis for recognition and transport of folic acid in mammalian cells. Curr Opin Struct Biol 2022; 74:102353. [PMID: 35303537 PMCID: PMC7612623 DOI: 10.1016/j.sbi.2022.102353] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 01/29/2022] [Accepted: 02/08/2022] [Indexed: 12/19/2022]
Abstract
Structural studies on mammalian vitamin transport lag behind other metabolites. Folates, also known as B9 vitamins, are essential cofactors in one-carbon transfer reactions in biology. Three different systems control folate uptake in the human body; folate receptors function to capture and internalise extracellular folates via endocytosis, whereas two major facilitator superfamily transporters, the reduced folate carrier (RFC; SLC19A1) and proton-coupled folate transporter (PCFT; SLC46A1) control the transport of folates across cellular membranes. Targeting specific folate transporters is being pursued as a route to developing new antifolates with improved pharmacology. Recent structures of the proton-coupled folate transporter, PCFT, revealed key insights into antifolate recognition and the mechanism of proton-coupled transport. Combined with previously determined structures of folate receptors and new predictions for the structure of the RFC, we are now able to develop a structure-based understanding of folate and antifolate recognition to accelerate efforts in antifolate drug development.
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Affiliation(s)
- Simon Newstead
- Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, UK.
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11
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Nijland M, Martínez Felices JM, Slotboom DJ, Thangaratnarajah C. Membrane transport of cobalamin. VITAMINS AND HORMONES 2022; 119:121-148. [PMID: 35337617 DOI: 10.1016/bs.vh.2022.01.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
A wide variety of organisms encode cobalamin-dependent enzymes catalyzing essential metabolic reactions, but the cofactor cobalamin (vitamin B12) is only synthesized by a subset of bacteria and archaea. The biosynthesis of cobalamin is complex and energetically costly, making cobalamin variants and precursors metabolically valuable. Auxotrophs for these molecules have evolved uptake mechanisms to compensate for the lack of a synthesis pathway. Bacterial transport of cobalamin involves the passage over one or two lipidic membranes in Gram-positive and -negative bacteria, respectively. In higher eukaryotes, a complex system of carriers, receptors and transporters facilitates the delivery of the essential molecule to the tissues. Biochemical and genetic approaches have identified different transporter families involved in cobalamin transport. The majority of the characterized cobalamin transporters are active transport systems that belong to the ATP-binding cassette (ABC) superfamily of transporters. In this chapter, we describe the different cobalamin transport systems characterized to date that are present in bacteria and humans, as well as yet-to-be-identified transporters.
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Affiliation(s)
- Mark Nijland
- University of Groningen, Faculty of Science and Engineering, Groningen Biomolecular Sciences and Biotechnology, Membrane Enzymology Group, Groningen, Netherlands
| | - Jose M Martínez Felices
- University of Groningen, Faculty of Science and Engineering, Groningen Biomolecular Sciences and Biotechnology, Membrane Enzymology Group, Groningen, Netherlands
| | - Dirk J Slotboom
- University of Groningen, Faculty of Science and Engineering, Groningen Biomolecular Sciences and Biotechnology, Membrane Enzymology Group, Groningen, Netherlands.
| | - Chancievan Thangaratnarajah
- University of Groningen, Faculty of Science and Engineering, Groningen Biomolecular Sciences and Biotechnology, Membrane Enzymology Group, Groningen, Netherlands
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12
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Frelet-Barrand A. Lactococcus lactis, an Attractive Cell Factory for the Expression of Functional Membrane Proteins. Biomolecules 2022; 12:180. [PMID: 35204681 PMCID: PMC8961550 DOI: 10.3390/biom12020180] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 01/17/2022] [Accepted: 01/21/2022] [Indexed: 01/27/2023] Open
Abstract
Membrane proteins play key roles in most crucial cellular processes, ranging from cell-to-cell communication to signaling processes. Despite recent improvements, the expression of functionally folded membrane proteins in sufficient amounts for functional and structural characterization remains a challenge. Indeed, it is still difficult to predict whether a protein can be overproduced in a functional state in some expression system(s), though studies of high-throughput screens have been published in recent years. Prokaryotic expression systems present several advantages over eukaryotic ones. Among them, Lactococcus lactis (L. lactis) has emerged in the last two decades as a good alternative expression system to E. coli. The purpose of this chapter is to describe L. lactis and its tightly inducible system, NICE, for the effective expression of membrane proteins from both prokaryotic and eukaryotic origins.
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Affiliation(s)
- Annie Frelet-Barrand
- FEMTO-ST Institute, UMR 6174, CNRS, Université Bourgogne Franche-Comté, 15B Avenue des Montboucons, CEDEX, 25030 Besançon, France
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13
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Younus I, Kochkina S, Choi CC, Sun W, Ford RC. ATP-Binding Cassette Transporters: Snap-on Complexes? Subcell Biochem 2022; 99:35-82. [PMID: 36151373 DOI: 10.1007/978-3-031-00793-4_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
ATP-binding cassette (ABC) transporters are one of the largest families of membrane proteins in prokaryotic organisms. Much is now understood about the structure of these transporters and many reviews have been written on that subject. In contrast, less has been written on the assembly of ABC transporter complexes and this will be a major focus of this book chapter. The complexes are formed from two cytoplasmic subunits that are highly conserved (in terms of their primary and three-dimensional structures) across the whole family. These ATP-binding subunits give rise to the name of the family. They must assemble with two transmembrane subunits that will typically form the permease component of the transporter. The transmembrane subunits have been found to be surprisingly diverse in structure when the whole family is examined, with seven distinct folds identified so far. Hence nucleotide-binding subunits appear to have been bolted on to a variety of transmembrane platforms during evolution, leading to a greater variety in function. Furthermore, many importers within the family utilise a further external substrate-binding component to trap scarce substrates and deliver them to the correct permease components. In this chapter, we will discuss whether assembly of the various ABC transporter subunits occurs with high fidelity within the crowded cellular environment and whether promiscuity in assembly of transmembrane and cytoplasmic components can occur. We also discuss the new AlphaFold protein structure prediction tool which predicts a new type of transmembrane domain fold within the ABC transporters that is associated with cation exporters of bacteria and plants.
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Affiliation(s)
- Iqra Younus
- Faculty of Biology, Medicine and Health, School of Biological Sciences, The University of Manchester, Manchester, UK
| | - Sofia Kochkina
- Faculty of Biology, Medicine and Health, School of Biological Sciences, The University of Manchester, Manchester, UK
| | - Cheri C Choi
- Faculty of Biology, Medicine and Health, School of Biological Sciences, The University of Manchester, Manchester, UK
| | - Wenjuan Sun
- Faculty of Biology, Medicine and Health, School of Biological Sciences, The University of Manchester, Manchester, UK
| | - Robert C Ford
- Faculty of Biology, Medicine and Health, School of Biological Sciences, The University of Manchester, Manchester, UK.
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14
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Insights into the bilayer-mediated toppling mechanism of a folate-specific ECF transporter by cryo-EM. Proc Natl Acad Sci U S A 2021; 118:2105014118. [PMID: 34408021 DOI: 10.1073/pnas.2105014118] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Energy-coupling factor (ECF)-type transporters are small, asymmetric membrane protein complexes (∼115 kDa) that consist of a membrane-embedded, substrate-binding protein (S component) and a tripartite ATP-hydrolyzing module (ECF module). They import micronutrients into bacterial cells and have been proposed to use a highly unusual transport mechanism, in which the substrate is dragged across the membrane by a toppling motion of the S component. However, it remains unclear how the lipid bilayer could accommodate such a movement. Here, we used cryogenic electron microscopy at 200 kV to determine structures of a folate-specific ECF transporter in lipid nanodiscs and detergent micelles at 2.7- and 3.4-Å resolution, respectively. The structures reveal an irregularly shaped bilayer environment around the membrane-embedded complex and suggest that toppling of the S component is facilitated by protein-induced membrane deformations. In this way, structural remodeling of the lipid bilayer environment is exploited to guide the transport process.
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15
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Ernst M, Robertson JL. The Role of the Membrane in Transporter Folding and Activity. J Mol Biol 2021; 433:167103. [PMID: 34139219 PMCID: PMC8756397 DOI: 10.1016/j.jmb.2021.167103] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 06/07/2021] [Accepted: 06/08/2021] [Indexed: 12/23/2022]
Abstract
The synthesis, folding, and function of membrane transport proteins are critical factors for defining cellular physiology. Since the stability of these proteins evolved amidst the lipid bilayer, it is no surprise that we are finding that many of these membrane proteins demonstrate coupling of their structure or activity in some way to the membrane. More and more transporter structures are being determined with some information about the surrounding membrane, and computational modeling is providing further molecular details about these solvation structures. Thus, the field is moving towards identifying which molecular mechanisms - lipid interactions, membrane perturbations, differential solvation, and bulk membrane effects - are involved in linking membrane energetics to transporter stability and function. In this review, we present an overview of these mechanisms and the growing evidence that the lipid bilayer is a major determinant of the fold, form, and function of membrane transport proteins in membranes.
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Affiliation(s)
- Melanie Ernst
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine in St. Louis, 660 South Euclid Avenue, St. Louis, MO 63110, USA
| | - Janice L Robertson
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine in St. Louis, 660 South Euclid Avenue, St. Louis, MO 63110, USA.
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16
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Knaup FH, Meyners C, Charalampidou A, Krajczy P, Purder PL, Ross T, Hausch F. Med Chem Remote: The Frontiers in Medicinal Chemistry 2021. ChemMedChem 2021; 16:2411-2416. [PMID: 34101362 DOI: 10.1002/cmdc.202100355] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Indexed: 12/21/2022]
Abstract
Digital, but delicious! The Frontiers in Medicinal Chemistry 2021 meeting, originally intended to take place in Darmstadt, carried on as an online event from March 8-10 this year. Even with pandemic restrictions, the event co-presented by the Medicinal Chemistry Division of the German Chemical Society (GDCh), the German Pharmaceutical Society (DPhG), and the Swiss Chemical Society (SCS) proved to be a success, showcasing excellent speakers and facilitating participant interaction in an ingenious virtual setting. Over 350 participants from more than 10 countries gathered to discuss the latest trends and directions in medicinal chemistry, with sessions on molecular glues, covalent fragments, transient binding pockets and more. This report presents a summary of the key lectures and activities at the event.
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Affiliation(s)
- Fabian H Knaup
- Department of Chemistry and Biochemistry, Clemens-Schöpf-Institute, Technical University Darmstadt, Alarich-Weiss Straße 4, 64287, Darmstadt, Germany
| | - Christian Meyners
- Department of Chemistry and Biochemistry, Clemens-Schöpf-Institute, Technical University Darmstadt, Alarich-Weiss Straße 4, 64287, Darmstadt, Germany
| | - Anna Charalampidou
- Department of Chemistry and Biochemistry, Clemens-Schöpf-Institute, Technical University Darmstadt, Alarich-Weiss Straße 4, 64287, Darmstadt, Germany
| | - Patryk Krajczy
- Department of Chemistry and Biochemistry, Clemens-Schöpf-Institute, Technical University Darmstadt, Alarich-Weiss Straße 4, 64287, Darmstadt, Germany
| | - Patrick L Purder
- Department of Chemistry and Biochemistry, Clemens-Schöpf-Institute, Technical University Darmstadt, Alarich-Weiss Straße 4, 64287, Darmstadt, Germany
| | - Tatjana Ross
- Merck Healthcare KGaA, Frankfurter Str. 250, 64293, Darmstadt
| | - Felix Hausch
- Department of Chemistry and Biochemistry, Clemens-Schöpf-Institute, Technical University Darmstadt, Alarich-Weiss Straße 4, 64287, Darmstadt, Germany
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17
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Abstract
ATP-binding cassette (ABC) transporters constitute one of the largest and most ancient protein superfamilies found in all living organisms. They function as molecular machines by coupling ATP binding, hydrolysis, and phosphate release to translocation of diverse substrates across membranes. The substrates range from vitamins, steroids, lipids, and ions to peptides, proteins, polysaccharides, and xenobiotics. ABC transporters undergo substantial conformational changes during substrate translocation. A comprehensive understanding of their inner workings thus requires linking these structural rearrangements to the different functional state transitions. Recent advances in single-particle cryogenic electron microscopy have not only delivered crucial information on the architecture of several medically relevant ABC transporters and their supramolecular assemblies, including the ATP-sensitive potassium channel and the peptide-loading complex, but also made it possible to explore the entire conformational space of these nanomachines under turnover conditions and thereby gain detailed mechanistic insights into their mode of action.
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Affiliation(s)
- Christoph Thomas
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, 60438 Frankfurt am Main, Germany; ,
| | - Robert Tampé
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, 60438 Frankfurt am Main, Germany; ,
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18
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Ploetz E, Schuurman-Wolters GK, Zijlstra N, Jager AW, Griffith DA, Guskov A, Gouridis G, Poolman B, Cordes T. Structural and biophysical characterization of the tandem substrate-binding domains of the ABC importer GlnPQ. Open Biol 2021; 11:200406. [PMID: 33823661 PMCID: PMC8025302 DOI: 10.1098/rsob.200406] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The ATP-binding cassette transporter GlnPQ is an essential uptake system that transports glutamine, glutamic acid and asparagine in Gram-positive bacteria. It features two extra-cytoplasmic substrate-binding domains (SBDs) that are linked in tandem to the transmembrane domain of the transporter. The two SBDs differ in their ligand specificities, binding affinities and their distance to the transmembrane domain. Here, we elucidate the effects of the tandem arrangement of the domains on the biochemical, biophysical and structural properties of the protein. For this, we determined the crystal structure of the ligand-free tandem SBD1-2 protein from Lactococcus lactis in the absence of the transporter and compared the tandem to the isolated SBDs. We also used isothermal titration calorimetry to determine the ligand-binding affinity of the SBDs and single-molecule Förster resonance energy transfer (smFRET) to relate ligand binding to conformational changes in each of the domains of the tandem. We show that substrate binding and conformational changes are not notably affected by the presence of the adjoining domain in the wild-type protein, and changes only occur when the linker between the domains is shortened. In a proof-of-concept experiment, we combine smFRET with protein-induced fluorescence enhancement (PIFE–FRET) and show that a decrease in SBD linker length is observed as a linear increase in donor-brightness for SBD2 while we can still monitor the conformational states (open/closed) of SBD1. These results demonstrate the feasibility of PIFE–FRET to monitor protein–protein interactions and conformational states simultaneously.
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Affiliation(s)
- Evelyn Ploetz
- Molecular Microscopy Research Group, Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands.,Department of Chemistry, Center for Nanosciences (CeNS) and Center for Integrated Proteins Science Munich (CiPSM), Ludwig Maximilians-Universität München, Butenandtstraße 11, 81377 Munich, Germany
| | - Gea K Schuurman-Wolters
- Groningen Biomolecular Science and Biotechnology Institute, Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Niels Zijlstra
- Physical and Synthetic Biology, Faculty of Biology, Großhaderner Straße 2-4, Ludwig-Maximilians-Universität München, 82152 Planegg-Martinsried, Germany
| | - Amarins W Jager
- Groningen Biomolecular Science and Biotechnology Institute, Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Douglas A Griffith
- Physical and Synthetic Biology, Faculty of Biology, Großhaderner Straße 2-4, Ludwig-Maximilians-Universität München, 82152 Planegg-Martinsried, Germany
| | - Albert Guskov
- Groningen Biomolecular Science and Biotechnology Institute, Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands.,Moscow Institute of Physics and Technology (MIPT), Institutskiy Pereulok 9, Dolgoprudny, Moscow Region 141701, Russian Federation
| | - Giorgos Gouridis
- Molecular Microscopy Research Group, Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands.,Structural Biology Division, Institute of Molecular Biology and Biotechnology (IMBB-FORTH), Nikolaou Plastira 100, Heraklion, Crete, Greece
| | - Bert Poolman
- Groningen Biomolecular Science and Biotechnology Institute, Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Thorben Cordes
- Molecular Microscopy Research Group, Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands.,Physical and Synthetic Biology, Faculty of Biology, Großhaderner Straße 2-4, Ludwig-Maximilians-Universität München, 82152 Planegg-Martinsried, Germany
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19
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Structural dynamics of ABC transporters: molecular simulation studies. Biochem Soc Trans 2021; 49:405-414. [PMID: 33634827 DOI: 10.1042/bst20200710] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 02/02/2021] [Accepted: 02/03/2021] [Indexed: 12/31/2022]
Abstract
The biological activities of living organisms involve various inputs and outputs. The ATP-driven substances (biomolecules) responsible for these kinds of activities through membrane (i.e. uptake and efflux of substrates) include ATP-binding cassette (ABC) transporters, some of which play important roles in multidrug resistance. The basic architecture of ABC transporters comprises transmembrane domains (TMDs) and nucleotide-binding domains (NBDs). The functional dynamics (substrate transport) of ABC transporters are realized by concerted motions, such as NBD dimerization, mechanical transmission via coupling helices (CHs), and the translocation of substrates through TMDs, which are induced by the binding and/or hydrolysis of ATP molecules and substrates. In this mini-review, we briefly discuss recent progresses in the structural dynamics as revealed by molecular simulation studies at all-atom (AA), coarse-grained (CG), and quantum mechanics/molecular mechanics (QM/MM) levels.
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20
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Elevator-type mechanisms of membrane transport. Biochem Soc Trans 2021; 48:1227-1241. [PMID: 32369548 PMCID: PMC7329351 DOI: 10.1042/bst20200290] [Citation(s) in RCA: 61] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 03/29/2020] [Accepted: 03/31/2020] [Indexed: 12/13/2022]
Abstract
Membrane transporters are integral membrane proteins that mediate the passage of solutes across lipid bilayers. These proteins undergo conformational transitions between outward- and inward-facing states, which lead to alternating access of the substrate-binding site to the aqueous environment on either side of the membrane. Dozens of different transporter families have evolved, providing a wide variety of structural solutions to achieve alternating access. A sub-set of structurally diverse transporters operate by mechanisms that are collectively named 'elevator-type'. These transporters have one common characteristic: they contain a distinct protein domain that slides across the membrane as a rigid body, and in doing so it 'drags" the transported substrate along. Analysis of the global conformational changes that take place in membrane transporters using elevator-type mechanisms reveals that elevator-type movements can be achieved in more than one way. Molecular dynamics simulations and experimental data help to understand how lipid bilayer properties may affect elevator movements and vice versa.
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21
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Setyawati I, Stanek WK, Majsnerowska M, Swier LJYM, Pardon E, Steyaert J, Guskov A, Slotboom DJ. In vitro reconstitution of dynamically interacting integral membrane subunits of energy-coupling factor transporters. eLife 2020; 9:64389. [PMID: 33350937 PMCID: PMC7755397 DOI: 10.7554/elife.64389] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Accepted: 12/02/2020] [Indexed: 01/03/2023] Open
Abstract
Energy-coupling factor (ECF) transporters mediate import of micronutrients in prokaryotes. They consist of an integral membrane S-component (that binds substrate) and ECF module (that powers transport by ATP hydrolysis). It has been proposed that different S-components compete for docking onto the same ECF module, but a minimal liposome-reconstituted system, required to substantiate this idea, is lacking. Here, we co-reconstituted ECF transporters for folate (ECF-FolT2) and pantothenate (ECF-PanT) into proteoliposomes, and assayed for crosstalk during active transport. The kinetics of transport showed that exchange of S-components is part of the transport mechanism. Competition experiments suggest much slower substrate association with FolT2 than with PanT. Comparison of a crystal structure of ECF-PanT with previously determined structures of ECF-FolT2 revealed larger conformational changes upon binding of folate than pantothenate, which could explain the kinetic differences. Our work shows that a minimal in vitro system with two reconstituted transporters recapitulates intricate kinetics behaviour observed in vivo.
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Affiliation(s)
- Inda Setyawati
- Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, Netherlands.,Biochemistry Department, Bogor Agricultural University, Bogor, Indonesia
| | - Weronika K Stanek
- Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, Netherlands
| | - Maria Majsnerowska
- Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, Netherlands
| | - Lotteke J Y M Swier
- Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, Netherlands
| | - Els Pardon
- Structural Biology Brussels, Vrije Universiteit Brussel, VUB, Brussels, Belgium.,VIB-VUB Center for Structural Biology, VIB, Brussels, Belgium
| | - Jan Steyaert
- Structural Biology Brussels, Vrije Universiteit Brussel, VUB, Brussels, Belgium.,VIB-VUB Center for Structural Biology, VIB, Brussels, Belgium
| | - Albert Guskov
- Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, Netherlands.,Moscow Institute of Physics and Technology, Dolgoprudny, Russian Federation
| | - Dirk J Slotboom
- Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, Netherlands
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22
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Turner ME, Huynh K, Carroll RK, Ahn SJ, Rice KC. Characterization of the Streptococcus mutans SMU.1703c-SMU.1702c Operon Reveals Its Role in Riboflavin Import and Response to Acid Stress. J Bacteriol 2020; 203:e00293-20. [PMID: 33077636 PMCID: PMC7950412 DOI: 10.1128/jb.00293-20] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Accepted: 10/15/2020] [Indexed: 11/20/2022] Open
Abstract
Streptococcus mutans utilizes numerous metabolite transporters to obtain essential nutrients in the "feast or famine" environment of the human mouth. S. mutans and most other streptococci are considered auxotrophic for several essential vitamins including riboflavin (vitamin B2), which is used to generate key cofactors and to perform numerous cellular redox reactions. Despite the well-known contributions of this vitamin to central metabolism, little is known about how S. mutans obtains and metabolizes B2 The uncharacterized protein SMU.1703c displays high sequence homology to the riboflavin transporter RibU. Deletion of SMU.1703c hindered S. mutans growth in complex and defined medium in the absence of saturating levels of exogenous riboflavin, whereas deletion of cotranscribed SMU.1702c alone had no apparent effect on growth. Expression of SMU.1703c in a Bacillus subtilis riboflavin auxotroph functionally complemented growth in nonsaturating riboflavin conditions. S. mutans was also able to grow on flavin adenine dinucleotide (FAD) or flavin mononucleotide (FMN) in an SMU.1703c-dependent manner. Deletion of SMU.1703c and/or SMU.1702c impacted S. mutans acid stress tolerance, as all mutants showed improved growth at pH 5.5 compared to that of the wild type when medium was supplemented with saturating riboflavin. Cooccurrence of SMU.1703c and SMU.1702c, a hypothetical PAP2 family acid phosphatase gene, appears unique to the streptococci and may suggest a connection of SMU.1702c to the acquisition or metabolism of flavins within this genus. Identification of SMU.1703c as a RibU-like riboflavin transporter furthers our understanding of how S. mutans acquires essential micronutrients within the oral cavity and how this pathogen successfully competes within nutrient-starved oral biofilms.IMPORTANCE Dental caries form when acid produced by oral bacteria erodes tooth enamel. This process is driven by the fermentative metabolism of cariogenic bacteria, most notably Streptococcus mutans Nutrient acquisition is key in the competitive oral cavity, and many organisms have evolved various strategies to procure carbon sources or necessary biomolecules. B vitamins, such as riboflavin, which many oral streptococci must scavenge from the oral environment, are necessary for survival within the competitive oral cavity. However, the primary mechanism and proteins involved in this process remain uncharacterized. This study is important because it identifies a key step in S. mutans riboflavin acquisition and cofactor generation, which may enable the development of novel anticaries treatment strategies via selective targeting of metabolite transporters.
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Affiliation(s)
- Matthew E Turner
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida, USA
| | - Khanh Huynh
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida, USA
| | - Ronan K Carroll
- Department of Biological Sciences, Ohio University, Athens, Ohio, USA
| | - Sang-Joon Ahn
- Department of Oral Biology, College of Dentistry, University of Florida, Gainesville, Florida, USA
| | - Kelly C Rice
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida, USA
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23
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Ford RC, Hellmich UA. What monomeric nucleotide binding domains can teach us about dimeric ABC proteins. FEBS Lett 2020; 594:3857-3875. [PMID: 32880928 DOI: 10.1002/1873-3468.13921] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 08/06/2020] [Accepted: 08/24/2020] [Indexed: 12/12/2022]
Abstract
The classic conceptualization of ATP binding cassette (ABC) transporter function is an ATP-dependent conformational change coupled to transport of a substrate across a biological membrane via the transmembrane domains (TMDs). The binding of two ATP molecules within the transporter's two nucleotide binding domains (NBDs) induces their dimerization. Despite retaining the ability to bind nucleotides, isolated NBDs frequently fail to dimerize. ABC proteins without a TMD, for example ABCE and ABCF, have NBDs tethered via elaborate linkers, further supporting that NBD dimerization does not readily occur for isolated NBDs. Intriguingly, even in full-length transporters, the NBD-dimerized, outward-facing state is not as frequently observed as might be expected. This leads to questions regarding what drives NBD interaction and the role of the TMDs or linkers. Understanding the NBD-nucleotide interaction and the subsequent NBD dimerization is thus pivotal for understanding ABC transporter activity in general. Here, we hope to provide new insights into ABC protein function by discussing the perplexing issue of (missing) NBD dimerization in isolation and in the context of full-length ABC proteins.
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Affiliation(s)
- Robert C Ford
- Faculty of Biology Medicine and Health, The University of Manchester, UK
| | - Ute A Hellmich
- Department of Chemistry, Johannes Gutenberg-University, Mainz, Germany.,Centre for Biomolecular Magnetic Resonance (BMRZ), Goethe-University, Frankfurt, Germany
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24
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Transporters of glucose and other carbohydrates in bacteria. Pflugers Arch 2020; 472:1129-1153. [PMID: 32372286 DOI: 10.1007/s00424-020-02379-0] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 04/01/2020] [Accepted: 04/02/2020] [Indexed: 12/18/2022]
Abstract
Glucose arguably is the most important energy carrier, carbon source for metabolites and building block for biopolymers in all kingdoms of life. The proper function of animal organs and tissues depends on the continuous supply of glucose from the bloodstream. Most animals can resorb only a small number of monosaccharides, mostly glucose, galactose and fructose, while all other sugars oligosaccharides and dietary fibers are degraded and metabolized by the microbiota of the lower intestine. Bacteria, in contrast, are omnivorous. They can import and metabolize structurally different sugars and, as a consortium of different species, utilize almost any sugar, sugar derivative and oligosaccharide occurring in nature. Bacteria have membrane transport systems for the uptake of sugars against steep concentration gradients energized by ATP, the proton motive force and the high energy glycolytic intermediate phosphoenolpyruvate (PEP). Different uptake mechanisms and the broad range of overlapping substrate specificities allow bacteria to quickly adapt to and colonize changing environments. Here, we review the structures and mechanisms of bacterial representatives of (i) ATP-dependent cassette (ABC) transporters, (ii) major facilitator (MFS) superfamily proton symporters, (iii) sodium solute symporters (SSS) and (iv) enzyme II integral membrane subunits of the bacterial PEP-dependent phosphotransferase system (PTS). We give a short overview on the distribution of transporter genes and their phylogenetic relationship in different bacterial species. Some sugar transporters are hijacked for import of bacteriophage DNA and antibacterial toxins (bacteriocins) and they facilitate the penetration of polar antibiotics. Finally, we describe how the expression and activity of certain sugar transporters are controlled in response to the availability of sugars and how the presence and uptake of sugars may affect pathogenicity and host-microbiota interactions.
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25
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Membrane mediated toppling mechanism of the folate energy coupling factor transporter. Nat Commun 2020; 11:1763. [PMID: 32273501 PMCID: PMC7145868 DOI: 10.1038/s41467-020-15554-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Accepted: 03/13/2020] [Indexed: 01/12/2023] Open
Abstract
Energy coupling factor (ECF) transporters are responsible for the uptake of micronutrients in bacteria and archaea. They consist of an integral membrane unit, the S-component, and a tripartite ECF module. It has been proposed that the S-component mediates the substrate transport by toppling over in the membrane when docking onto an ECF module. Here, we present multi-scale molecular dynamics simulations and in vitro experiments to study the molecular toppling mechanism of the S-component of a folate-specific ECF transporter. Simulations reveal a strong bending of the membrane around the ECF module that provides a driving force for toppling of the S-component. The stability of the toppled state depends on the presence of non-bilayer forming lipids, as confirmed by folate transport activity measurements. Together, our data provide evidence for a lipid-dependent toppling-based mechanism for the folate-specific ECF transporter, a mechanism that might apply to other ECF transporters.
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26
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Guo Y. Be Cautious with Crystal Structures of Membrane Proteins or Complexes Prepared in Detergents. CRYSTALS 2020; 10:86. [PMID: 32494365 PMCID: PMC7269168 DOI: 10.3390/cryst10020086] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Membrane proteins are an important class of macromolecules found in all living organisms and many of them serve as important drug targets. In order to understand their biological and biochemical functions and to exploit them for structure-based drug design, high-resolution and accurate structures of membrane proteins are needed, but are still rarely available, e.g., predominantly from X-ray crystallography, and more recently from single particle cryo-EM - an increasingly powerful tool for membrane protein structure determination. However, while protein-lipid interactions play crucial roles for the structural and functional integrity of membrane proteins, for historical reasons and due to technological limitations, until recently, the primary method for membrane protein crystallization has relied on detergents. Bicelle and lipid cubic phase (LCP) methods have also been used for membrane protein crystallization, but the first step requires detergent extraction of the protein from its native cell membrane. The resulting, crystal structures have been occasionally questioned, but such concerns were generally dismissed as accidents or ignored. However, even a hint of controversy indicates that methodological drawbacks in such structural research may exist. In the absence of caution, structures determined using these methods are often assumed to be correct, which has led to surprising hypotheses for their mechanisms of action. In this communication, several examples of structural studies on membrane proteins or complexes will be discussed: Resistance-Nodulation-Division (RND) family transporters, microbial rhodopsins, Tryptophan-rich Sensory Proteins (TSPO), and Energy-Coupling Factor (ECF) type ABC transporters. These analyses should focus the attention of membrane protein structural biologists on the potential problems in structure determination relying on detergent-based methods. Furthermore, careful examination of membrane proteins in their native cell environments by biochemical and biophysical techniques is warranted, and completely detergent-free systems for membrane protein research are crucially needed.
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Affiliation(s)
- Youzhong Guo
- Department of Medicinal Chemistry & Institute for Structural Biology, Drug Discovery and Development, Virginia Commonwealth University, Richmond, VA 23298-0540, USA
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27
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Abstract
Energy-coupling factor (ECF)-type ATP-binding cassette (ABC) transporters catalyze membrane transport of micronutrients in prokaryotes. Crystal structures and biochemical characterization have revealed that ECF transporters are mechanistically distinct from other ABC transport systems. Notably, ECF transporters make use of small integral membrane subunits (S-components) that are predicted to topple over in the membrane when carrying the bound substrate from the extracellular side of the bilayer to the cytosol. Here, we review the phylogenetic diversity of ECF transporters as well as recent structural and biochemical advancements that have led to the postulation of conceptually different mechanistic models. These models can be described as power stroke and thermal ratchet. Structural data indicate that the lipid composition and bilayer structure are likely to have great impact on the transport function. We argue that study of ECF transporters could lead to generic insight into membrane protein structure, dynamics, and interaction.
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Affiliation(s)
- S Rempel
- Gr oningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9747 AG Groningen, The Netherlands; , ,
| | - W K Stanek
- Gr oningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9747 AG Groningen, The Netherlands; , ,
| | - D J Slotboom
- Gr oningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9747 AG Groningen, The Netherlands; , , .,Zernike Institute for Advanced Materials, University of Groningen, 9747 AG Groningen, The Netherlands
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28
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Finkenwirth F, Sippach M, Pecina SN, Gäde M, Ruta J, Ricke A, Bondarenko E, Klare JP, Zinke M, Lange S, Lange A, Steinhoff HJ, Eitinger T. Dynamic interactions of CbiN and CbiM trigger activity of a cobalt energy-coupling-factor transporter. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2019; 1862:183114. [PMID: 31666178 DOI: 10.1016/j.bbamem.2019.183114] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 10/01/2019] [Accepted: 10/08/2019] [Indexed: 11/26/2022]
Abstract
Energy-coupling factor (ECF) transporters for uptake of vitamins and transition-metal ions into prokaryotic cells share a common architecture consisting of a substrate-specific integral membrane protein (S), a transmembrane coupling protein (T) and two cytoplasmic ATP-binding-cassette-family ATPases. S components rotate within the membrane to expose their binding pockets alternately to the exterior and the cytoplasm. In contrast to vitamin transporters, metal-specific systems rely on additional proteins with essential but poorly understood functions. CbiN, a membrane protein composed of two transmembrane helices tethered by an extracytoplasmic loop of 37 amino-acid residues represents the auxiliary component that temporarily interacts with the CbiMQO2 Co2+ transporter. CbiN was previously shown to induce significant Co2+ transport activity in the absence of CbiQO2 in cells producing the S component CbiM plus CbiN or a Cbi(MN) fusion. Here we analyzed the mode of interaction between the two protein domains. Any deletion in the CbiN loop abolished transport activity. In silico predicted protein-protein contacts between segments of the CbiN loop and loops in CbiM were confirmed by cysteine-scanning mutagenesis and crosslinking. Likewise, an ordered structure of the CbiN loop was observed by electron paramagnetic resonance analysis after site-directed spin labeling. The N-terminal loop of CbiM containing three of four metal ligands was partially immobilized in wild-type Cbi(MN) but completely immobile in inactive variants with CbiN loop deletions. Decreased dynamics of the inactive form was also detected by solid-state nuclear magnetic resonance of isotope-labeled protein in proteoliposomes. In conclusion, CbiM-CbiN loop-loop interactions facilitate metal insertion into the binding pocket.
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Affiliation(s)
- Friedrich Finkenwirth
- Institut für Biologie/Mikrobiologie, Humboldt-Universität zu Berlin, 10099 Berlin, Germany
| | - Michael Sippach
- Fachbereich Physik, Universität Osnabrück, 49076 Osnabrück, Germany
| | - Sinah N Pecina
- Institut für Biologie/Mikrobiologie, Humboldt-Universität zu Berlin, 10099 Berlin, Germany
| | - Mario Gäde
- Institut für Biologie/Mikrobiologie, Humboldt-Universität zu Berlin, 10099 Berlin, Germany
| | - Julia Ruta
- Department of Molecular Biophysics, Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), 13125 Berlin, Germany; Institut für Biologie, Humboldt-Universität zu Berlin, 10099 Berlin, Germany
| | - Adrian Ricke
- Fachbereich Physik, Universität Osnabrück, 49076 Osnabrück, Germany
| | - Elena Bondarenko
- Fachbereich Physik, Universität Osnabrück, 49076 Osnabrück, Germany
| | - Johann P Klare
- Fachbereich Physik, Universität Osnabrück, 49076 Osnabrück, Germany
| | - Maximilian Zinke
- Department of Molecular Biophysics, Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), 13125 Berlin, Germany
| | - Sascha Lange
- Department of Molecular Biophysics, Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), 13125 Berlin, Germany
| | - Adam Lange
- Department of Molecular Biophysics, Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), 13125 Berlin, Germany; Institut für Biologie, Humboldt-Universität zu Berlin, 10099 Berlin, Germany
| | | | - Thomas Eitinger
- Institut für Biologie/Mikrobiologie, Humboldt-Universität zu Berlin, 10099 Berlin, Germany.
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29
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Bousis S, Setyawati I, Diamanti E, Slotboom DJ, Hirsch AKH. Energy-Coupling Factor Transporters as Novel Antimicrobial Targets. ADVANCED THERAPEUTICS 2019. [DOI: 10.1002/adtp.201800066] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Spyridon Bousis
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS) - Helmholtz Centre for Infection Research (HZI); Department of Drug Design and Optimization; Campus Building E8.1 66123 Saarbrücken Germany
- Stratingh Institute for Chemistry; University of Groningen; Nijenborgh 7 9747AG Groningen The Netherlands
- Department of Pharmacy; Saarland University; Saarbrücken, Campus Building E8.1 66123 Saarbrücken Germany
| | - Inda Setyawati
- Groningen Biomolecular Sciences and Biotechnology Institute; University of Groningen; Nijenborgh 4 9747AG Groningen The Netherlands
- Department of Biochemistry; Bogor Agricultural University; Dramaga 16680 Bogor Indonesia
| | - Eleonora Diamanti
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS) - Helmholtz Centre for Infection Research (HZI); Department of Drug Design and Optimization; Campus Building E8.1 66123 Saarbrücken Germany
- Stratingh Institute for Chemistry; University of Groningen; Nijenborgh 7 9747AG Groningen The Netherlands
| | - Dirk J. Slotboom
- Groningen Biomolecular Sciences and Biotechnology Institute; University of Groningen; Nijenborgh 4 9747AG Groningen The Netherlands
- Department of Biochemistry; Bogor Agricultural University; Dramaga 16680 Bogor Indonesia
| | - Anna K. H. Hirsch
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS) - Helmholtz Centre for Infection Research (HZI); Department of Drug Design and Optimization; Campus Building E8.1 66123 Saarbrücken Germany
- Stratingh Institute for Chemistry; University of Groningen; Nijenborgh 7 9747AG Groningen The Netherlands
- Department of Pharmacy; Saarland University; Saarbrücken, Campus Building E8.1 66123 Saarbrücken Germany
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30
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Voith von Voithenberg L, Park J, Stübe R, Lux C, Lee Y, Philippar K. A Novel Prokaryote-Type ECF/ABC Transporter Module in Chloroplast Metal Homeostasis. FRONTIERS IN PLANT SCIENCE 2019; 10:1264. [PMID: 31736987 PMCID: PMC6828968 DOI: 10.3389/fpls.2019.01264] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Accepted: 09/11/2019] [Indexed: 05/18/2023]
Abstract
During evolution, chloroplasts, which originated by endosymbiosis of a prokaryotic ancestor of today's cyanobacteria with a eukaryotic host cell, were established as the site for photosynthesis. Therefore, chloroplast organelles are loaded with transition metals including iron, copper, and manganese, which are essential for photosynthetic electron transport due to their redox capacity. Although transport, storage, and cofactor-assembly of metal ions in chloroplasts are tightly controlled and crucial throughout plant growth and development, knowledge on the molecular nature of chloroplast metal-transport proteins is still fragmentary. Here, we characterized the soluble, ATP-binding ABC-transporter subunits ABCI10 and ABCI11 in Arabidopsis thaliana, which show similarities to components of prokaryotic, multisubunit ABC transporters. Both ABCI10 and ABCI11 proteins appear to be strongly attached to chloroplast-intrinsic membranes, most likely inner envelopes for ABCI10 and possibly plastoglobuli for ABCI11. Loss of ABCI10 and ABCI11 gene products in Arabidopsis leads to extremely dwarfed, albino plants showing impaired chloroplast biogenesis and deregulated metal homeostasis. Further, we identified the membrane-intrinsic protein ABCI12 as potential interaction partner for ABCI10 in the inner envelope. Our results suggest that ABCI12 inserts into the chloroplast inner envelope membrane most likely with five predicted α-helical transmembrane domains and represents the membrane-intrinsic subunit of a prokaryotic-type, energy-coupling factor (ECF) ABC-transporter complex. In bacteria, these multisubunit ECF importers are widely distributed for the uptake of nickel and cobalt metal ions as well as for import of vitamins and several other metabolites. Therefore, we propose that ABCI10 (as the ATPase A-subunit) and ABCI12 (as the membrane-intrinsic, energy-coupling T-subunit) are part of a novel, chloroplast envelope-localized, AAT energy-coupling module of a prokaryotic-type ECF transporter, most likely involved in metal ion uptake.
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Affiliation(s)
| | - Jiyoung Park
- Department of Life Science, Pohang University of Science and Technology, Pohang, South Korea
| | - Roland Stübe
- Plant Biochemistry and Physiology, Department of Biology I, LMU München, Planegg-Martinsried, Germany
| | - Christopher Lux
- Plant Biology, Center for Human and Molecular Biology (ZHMB), Saarland University, Saarbrücken, Germany
| | - Youngsook Lee
- Department of Life Science, Pohang University of Science and Technology, Pohang, South Korea
| | - Katrin Philippar
- Plant Biology, Center for Human and Molecular Biology (ZHMB), Saarland University, Saarbrücken, Germany
- *Correspondence: Katrin Philippar,
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31
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Voith von Voithenberg L, Park J, Stübe R, Lux C, Lee Y, Philippar K. A Novel Prokaryote-Type ECF/ABC Transporter Module in Chloroplast Metal Homeostasis. FRONTIERS IN PLANT SCIENCE 2019; 10:1264. [PMID: 31736987 DOI: 10.3389/fpls201901264] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Accepted: 09/11/2019] [Indexed: 05/22/2023]
Abstract
During evolution, chloroplasts, which originated by endosymbiosis of a prokaryotic ancestor of today's cyanobacteria with a eukaryotic host cell, were established as the site for photosynthesis. Therefore, chloroplast organelles are loaded with transition metals including iron, copper, and manganese, which are essential for photosynthetic electron transport due to their redox capacity. Although transport, storage, and cofactor-assembly of metal ions in chloroplasts are tightly controlled and crucial throughout plant growth and development, knowledge on the molecular nature of chloroplast metal-transport proteins is still fragmentary. Here, we characterized the soluble, ATP-binding ABC-transporter subunits ABCI10 and ABCI11 in Arabidopsis thaliana, which show similarities to components of prokaryotic, multisubunit ABC transporters. Both ABCI10 and ABCI11 proteins appear to be strongly attached to chloroplast-intrinsic membranes, most likely inner envelopes for ABCI10 and possibly plastoglobuli for ABCI11. Loss of ABCI10 and ABCI11 gene products in Arabidopsis leads to extremely dwarfed, albino plants showing impaired chloroplast biogenesis and deregulated metal homeostasis. Further, we identified the membrane-intrinsic protein ABCI12 as potential interaction partner for ABCI10 in the inner envelope. Our results suggest that ABCI12 inserts into the chloroplast inner envelope membrane most likely with five predicted α-helical transmembrane domains and represents the membrane-intrinsic subunit of a prokaryotic-type, energy-coupling factor (ECF) ABC-transporter complex. In bacteria, these multisubunit ECF importers are widely distributed for the uptake of nickel and cobalt metal ions as well as for import of vitamins and several other metabolites. Therefore, we propose that ABCI10 (as the ATPase A-subunit) and ABCI12 (as the membrane-intrinsic, energy-coupling T-subunit) are part of a novel, chloroplast envelope-localized, AAT energy-coupling module of a prokaryotic-type ECF transporter, most likely involved in metal ion uptake.
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Affiliation(s)
| | - Jiyoung Park
- Department of Life Science, Pohang University of Science and Technology, Pohang, South Korea
| | - Roland Stübe
- Plant Biochemistry and Physiology, Department of Biology I, LMU München, Planegg-Martinsried, Germany
| | - Christopher Lux
- Plant Biology, Center for Human and Molecular Biology (ZHMB), Saarland University, Saarbrücken, Germany
| | - Youngsook Lee
- Department of Life Science, Pohang University of Science and Technology, Pohang, South Korea
| | - Katrin Philippar
- Plant Biology, Center for Human and Molecular Biology (ZHMB), Saarland University, Saarbrücken, Germany
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32
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Hofmann JD, Otto A, Berges M, Biedendieck R, Michel AM, Becher D, Jahn D, Neumann-Schaal M. Metabolic Reprogramming of Clostridioides difficile During the Stationary Phase With the Induction of Toxin Production. Front Microbiol 2018; 9:1970. [PMID: 30186274 PMCID: PMC6110889 DOI: 10.3389/fmicb.2018.01970] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Accepted: 08/03/2018] [Indexed: 12/20/2022] Open
Abstract
The obligate anaerobe, spore forming bacterium Clostridioides difficile (formerly Clostridium difficile) causes nosocomial and community acquired diarrhea often associated with antibiotic therapy. Major virulence factors of the bacterium are the two large clostridial toxins TcdA and TcdB. The production of both toxins was found strongly connected to the metabolism and the nutritional status of the growth environment. Here, we systematically investigated the changes of the gene regulatory, proteomic and metabolic networks of C. difficile 630Δerm underlying the adaptation to the non-growing state in the stationary phase. Integrated data from time-resolved transcriptome, proteome and metabolome investigations performed under defined growth conditions uncovered multiple adaptation strategies. Overall changes in the cellular processes included the downregulation of ribosome production, lipid metabolism, cold shock proteins, spermine biosynthesis, and glycolysis and in the later stages of riboflavin and coenzyme A (CoA) biosynthesis. In contrast, different chaperones, several fermentation pathways, and cysteine, serine, and pantothenate biosynthesis were found upregulated. Focusing on the Stickland amino acid fermentation and the central carbon metabolism, we discovered the ability of C. difficile to replenish its favored amino acid cysteine by a pathway starting from the glycolytic 3-phosphoglycerate via L-serine as intermediate. Following the growth course, the reductive equivalent pathways used were sequentially shifted from proline via leucine/phenylalanine to the central carbon metabolism first to butanoate fermentation and then further to lactate fermentation. The toxin production was found correlated mainly to fluxes of the central carbon metabolism. Toxin formation in the supernatant was detected when the flux changed from butanoate to lactate synthesis in the late stationary phase. The holistic view derived from the combination of transcriptome, proteome and metabolome data allowed us to uncover the major metabolic strategies that are used by the clostridial cells to maintain its cellular homeostasis and ensure survival under starvation conditions.
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Affiliation(s)
- Julia D Hofmann
- Department of Bioinformatics and Biochemistry, Technische Universität Braunschweig, Braunschweig, Germany.,Braunschweig Integrated Centre of Systems Biology (BRICS), Braunschweig, Germany
| | - Andreas Otto
- Department for Microbial Proteomics, University of Greifswald, Greifswald, Germany
| | - Mareike Berges
- Braunschweig Integrated Centre of Systems Biology (BRICS), Braunschweig, Germany.,Institute of Microbiology, Technische Universität Braunschweig, Braunschweig, Germany
| | - Rebekka Biedendieck
- Braunschweig Integrated Centre of Systems Biology (BRICS), Braunschweig, Germany.,Institute of Microbiology, Technische Universität Braunschweig, Braunschweig, Germany
| | - Annika-Marisa Michel
- Braunschweig Integrated Centre of Systems Biology (BRICS), Braunschweig, Germany.,Institute of Microbiology, Technische Universität Braunschweig, Braunschweig, Germany
| | - Dörte Becher
- Department for Microbial Proteomics, University of Greifswald, Greifswald, Germany
| | - Dieter Jahn
- Braunschweig Integrated Centre of Systems Biology (BRICS), Braunschweig, Germany.,Institute of Microbiology, Technische Universität Braunschweig, Braunschweig, Germany
| | - Meina Neumann-Schaal
- Department of Bioinformatics and Biochemistry, Technische Universität Braunschweig, Braunschweig, Germany.,Braunschweig Integrated Centre of Systems Biology (BRICS), Braunschweig, Germany.,Leibniz Institute DSMZ - German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
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33
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Cysteine-mediated decyanation of vitamin B12 by the predicted membrane transporter BtuM. Nat Commun 2018; 9:3038. [PMID: 30072686 PMCID: PMC6072759 DOI: 10.1038/s41467-018-05441-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 07/04/2018] [Indexed: 01/11/2023] Open
Abstract
Uptake of vitamin B12 is essential for many prokaryotes, but in most cases the membrane proteins involved are yet to be identified. We present the biochemical characterization and high-resolution crystal structure of BtuM, a predicted bacterial vitamin B12 uptake system. BtuM binds vitamin B12 in its base-off conformation, with a cysteine residue as axial ligand of the corrin cobalt ion. Spectroscopic analysis indicates that the unusual thiolate coordination allows for decyanation of vitamin B12. Chemical modification of the substrate is a property other characterized vitamin B12-transport proteins do not exhibit. Uptake of vitamin B12 is essential for many prokaryotes, but in most cases the membrane proteins involved are yet to be identified. Here, the authors use X-ray crystallography and spectroscopy to characterize BtuM, a predicted bacterial substrate-modifying vitamin B12 transporter.
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34
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Cryo-EM structure of the human neutral amino acid transporter ASCT2. Nat Struct Mol Biol 2018; 25:515-521. [PMID: 29872227 DOI: 10.1038/s41594-018-0076-y] [Citation(s) in RCA: 94] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Accepted: 04/27/2018] [Indexed: 12/17/2022]
Abstract
Human ASCT2 belongs to the SLC1 family of secondary transporters and is specific for the transport of small neutral amino acids. ASCT2 is upregulated in cancer cells and serves as the receptor for many retroviruses; hence, it has importance as a potential drug target. Here we used single-particle cryo-EM to determine a structure of the functional and unmodified human ASCT2 at 3.85-Å resolution. ASCT2 forms a homotrimeric complex in which each subunit contains a transport and a scaffold domain. Prominent extracellular extensions on the scaffold domain form the predicted docking site for retroviruses. Relative to structures of other SLC1 members, ASCT2 is in the most extreme inward-oriented state, with the transport domain largely detached from the central scaffold domain on the cytoplasmic side. This domain detachment may be required for substrate binding and release on the intracellular side of the membrane.
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35
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Santos JA, Rempel S, Mous ST, Pereira CT, Ter Beek J, de Gier JW, Guskov A, Slotboom DJ. Functional and structural characterization of an ECF-type ABC transporter for vitamin B12. eLife 2018; 7:35828. [PMID: 29809140 PMCID: PMC5997447 DOI: 10.7554/elife.35828] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Accepted: 05/26/2018] [Indexed: 01/01/2023] Open
Abstract
Vitamin B12 (cobalamin) is the most complex B-type vitamin and is synthetized exclusively in a limited number of prokaryotes. Its biologically active variants contain rare organometallic bonds, which are used by enzymes in a variety of central metabolic pathways such as L-methionine synthesis and ribonucleotide reduction. Although its biosynthesis and role as co-factor are well understood, knowledge about uptake of cobalamin by prokaryotic auxotrophs is scarce. Here, we characterize a cobalamin-specific ECF-type ABC transporter from Lactobacillus delbrueckii, ECF-CbrT, and demonstrate that it mediates the specific, ATP-dependent uptake of cobalamin. We solved the crystal structure of ECF-CbrT in an apo conformation to 3.4 Å resolution. Comparison with the ECF transporter for folate (ECF-FolT2) from the same organism, reveals how the identical ECF module adjusts to interact with the different substrate binding proteins FolT2 and CbrT. ECF-CbrT is unrelated to the well-characterized B12 transporter BtuCDF, but their biochemical features indicate functional convergence.
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Affiliation(s)
- Joana A Santos
- Groningen Biomolecular and Biotechnology Institute (GBB), University of Groningen, Groningen, The Netherlands
| | - Stephan Rempel
- Groningen Biomolecular and Biotechnology Institute (GBB), University of Groningen, Groningen, The Netherlands
| | - Sandra Tm Mous
- Groningen Biomolecular and Biotechnology Institute (GBB), University of Groningen, Groningen, The Netherlands
| | | | - Josy Ter Beek
- Groningen Biomolecular and Biotechnology Institute (GBB), University of Groningen, Groningen, The Netherlands
| | - Jan-Willem de Gier
- Department of Biochemistry and Biophysics, Center for Biomembrane Research, Stockholm University, Stockholm, Sweden
| | - Albert Guskov
- Groningen Biomolecular and Biotechnology Institute (GBB), University of Groningen, Groningen, The Netherlands
| | - Dirk J Slotboom
- Groningen Biomolecular and Biotechnology Institute (GBB), University of Groningen, Groningen, The Netherlands.,Zernike Institute for Advanced Materials, University of Groningen, Groningen, The Netherlands
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Xiao J, Zhu Y, Huddleston S, Li P, Xiao B, Farha OK, Ameer GA. Copper Metal-Organic Framework Nanoparticles Stabilized with Folic Acid Improve Wound Healing in Diabetes. ACS NANO 2018; 12:1023-1032. [PMID: 29406741 DOI: 10.1021/acsnano.7b01850] [Citation(s) in RCA: 209] [Impact Index Per Article: 34.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The successful treatment of chronic nonhealing wounds requires strategies that promote angiogenesis, collagen deposition, and re-epithelialization of the wound. Copper ions have been reported to stimulate angiogenesis; however, several applications of copper salts or oxides to the wound bed are required, leading to variable outcomes and raising toxicity concerns. We hypothesized that copper-based metal-organic framework nanoparticles (Cu-MOF NPs), referred to as HKUST-1, which are rapidly degraded in protein solutions, can be modified to slowly release Cu2+, resulting in reduced toxicity and improved wound healing rates. Folic acid was added during HKUST-1 synthesis to generate folic-acid-modified HKUST-1 (F-HKUST-1). The effect of folic acid incorporation on NP stability, size, hydrophobicity, surface area, and copper ion release profile was measured. In addition, cytotoxicity and in vitro cell migration processes due to F-HKUST-1 and HKUST-1 were evaluated. Wound closure rates were assessed using the splinted excisional dermal wound model in diabetic mice. The incorporation of folic acid into HKUST-1 enabled the slow release of copper ions, which reduced cytotoxicity and enhanced cell migration in vitro. In vivo, F-HKUST-1 induced angiogenesis, promoted collagen deposition and re-epithelialization, and increased wound closure rates. These results demonstrate that folic acid incorporation into HKUST-1 NPs is a simple, safe, and promising approach to control Cu2+ release, thus enabling the direct application of Cu-MOF NPs to wounds.
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Affiliation(s)
- Jisheng Xiao
- Biomedical Engineering Department, Northwestern University , 2145 Sheridan Road, Evanston, Illinois 60208, United States
- International Institute for Nanotechnology, Northwestern University , 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Yunxiao Zhu
- Biomedical Engineering Department, Northwestern University , 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Samantha Huddleston
- Biomedical Engineering Department, Northwestern University , 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Peng Li
- Department of Chemistry, Northwestern University , 2145 Sheridan Road, Evanston, Illinois 60208, United States
- International Institute for Nanotechnology, Northwestern University , 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Baixue Xiao
- Biomedical Engineering Department, Northwestern University , 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Omar K Farha
- Department of Chemistry, Northwestern University , 2145 Sheridan Road, Evanston, Illinois 60208, United States
- International Institute for Nanotechnology, Northwestern University , 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Guillermo A Ameer
- Biomedical Engineering Department, Northwestern University , 2145 Sheridan Road, Evanston, Illinois 60208, United States
- Department of Surgery, Feinberg School of Medicine, Northwestern University , Chicago, Illinois 60611, United States
- Chemistry of Life Processes Institute, Northwestern University , Evanston, Illinois 60208, United States
- Simpson Querrey Institute for BioNanotechnology, Northwestern University , Chicago, Illinois 60611, United States
- International Institute for Nanotechnology, Northwestern University , 2145 Sheridan Road, Evanston, Illinois 60208, United States
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Zhong XF, Zhang YB, Huang GD, Ouyang YZ, Liao DJ, Peng JW, Huang WZ. Proteomic analysis of stachyose contribution to the growth of Lactobacillus acidophilus CICC22162. Food Funct 2018; 9:2979-2988. [DOI: 10.1039/c8fo00528a] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Stachyose is a functional oligosaccharide, acting as a potential prebiotic for colonic fermentation.
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Affiliation(s)
- Xian-feng Zhong
- Department of Food Science
- Foshan University
- Foshan 528231
- China
- Foshan Engineering Research Center for Brewing Technology
| | - Yu-bo Zhang
- Department of Food Science
- Foshan University
- Foshan 528231
- China
- Foshan Engineering Research Center for Brewing Technology
| | - Gui-dong Huang
- Department of Food Science
- Foshan University
- Foshan 528231
- China
- Foshan Engineering Research Center for Brewing Technology
| | - Yong-zhong Ouyang
- School of Environmental and Chemical Engineering
- Foshan University
- Foshan 528231
- China
| | | | - Jia-wei Peng
- Department of Food Science
- Foshan University
- Foshan 528231
- China
- Foshan Engineering Research Center for Brewing Technology
| | - Wei-zhi Huang
- Department of Food Science
- Foshan University
- Foshan 528231
- China
- Foshan Engineering Research Center for Brewing Technology
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38
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Jaehme M, Singh R, Garaeva AA, Duurkens RH, Slotboom DJ. PnuT uses a facilitated diffusion mechanism for thiamine uptake. J Gen Physiol 2017; 150:41-50. [PMID: 29203477 PMCID: PMC5749112 DOI: 10.1085/jgp.201711850] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Accepted: 10/26/2017] [Indexed: 12/17/2022] Open
Abstract
Membrane transporters of the bacterial pyridine nucleotide uptake (Pnu) family mediate the uptake of various B-type vitamins. For example, the PnuT transporters have specificity for vitamin B1 (thiamine). It has been hypothesized that Pnu transporters are facilitators that allow passive transport of the vitamin substrate across the membrane. Metabolic trapping by phosphorylation would then lead to accumulation of the transported substrates in the cytoplasm. However, experimental evidence for such a transport mechanism is lacking. Here, to determine the mechanism of thiamine transport, we purify PnuTSw from Shewanella woodyi and reconstitute it in liposomes to determine substrate binding and transport properties. We show that the electrochemical gradient of thiamine solely determines the direction of transport, consistent with a facilitated diffusion mechanism. Further, PnuTSw can bind and transport thiamine as well as the thiamine analogues pyrithiamine and oxythiamine, but does not recognize the phosphorylated derivatives thiamine monophosphate and thiamine pyrophosphate as substrates, consistent with a metabolic trapping mechanism. Guided by the crystal structure of the homologous nicotinamide riboside transporter PnuC, we perform mutagenesis experiments, which reveal residues involved in substrate binding and gating. The facilitated diffusion mechanism of transport used by PnuTSw contrasts sharply with the active transport mechanisms used by other bacterial thiamine transporters.
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Affiliation(s)
- Michael Jaehme
- Groningen Biomolecular Science and Biotechnology Institute, University of Groningen, Groningen, Netherlands
| | - Rajkumar Singh
- Groningen Biomolecular Science and Biotechnology Institute, University of Groningen, Groningen, Netherlands
| | - Alisa A Garaeva
- Groningen Biomolecular Science and Biotechnology Institute, University of Groningen, Groningen, Netherlands
| | - Ria H Duurkens
- Groningen Biomolecular Science and Biotechnology Institute, University of Groningen, Groningen, Netherlands
| | - Dirk-Jan Slotboom
- Groningen Biomolecular Science and Biotechnology Institute, University of Groningen, Groningen, Netherlands
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Single-molecule visualization of conformational changes and substrate transport in the vitamin B 12 ABC importer BtuCD-F. Nat Commun 2017; 8:1652. [PMID: 29162829 PMCID: PMC5698293 DOI: 10.1038/s41467-017-01815-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2016] [Accepted: 10/18/2017] [Indexed: 11/15/2022] Open
Abstract
ATP-binding cassette (ABC) transporters form the largest class of active membrane transport proteins. Binding and hydrolysis of ATP by their highly conserved nucleotide-binding domains drive conformational changes of the complex that mediate transport of substrate across the membrane. The vitamin B12 importer BtuCD-F in Escherichia coli is an extensively studied model system. The periplasmic soluble binding protein BtuF binds the ligand; the transmembrane and ATPase domains BtuCD mediate translocation. Here we report the direct observation at the single-molecule level of ATP, vitamin B12 and BtuF-induced events in the transporter complex embedded in liposomes. Single-molecule fluorescence imaging techniques reveal that membrane-embedded BtuCD forms a stable complex with BtuF, regardless of the presence of ATP and vitamin B12. We observe that a vitamin B12 molecule remains bound to the complex for tens of seconds, during which several ATP hydrolysis cycles can take place, before it is being transported across the membrane. The vitamin B12 importer BtuCD-F is a type II ATP-binding cassette transporter. Here the authors use single-molecule fluorescence techniques to analyse ATP hydrolysis and substrate transport in individual BtuCD-F complexes embedded in liposomes, and propose a transport model.
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Crystal Structure of a Group I Energy Coupling Factor Vitamin Transporter S Component in Complex with Its Cognate Substrate. Cell Chem Biol 2017; 23:827-836. [PMID: 27447050 PMCID: PMC5037267 DOI: 10.1016/j.chembiol.2016.06.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Revised: 05/18/2016] [Accepted: 06/02/2016] [Indexed: 12/27/2022]
Abstract
Energy coupling factor (ECF) transporters are responsible for the uptake of essential scarce nutrients in prokaryotes. This ATP-binding cassette transporter family comprises two subgroups that share a common architecture forming a tripartite membrane protein complex consisting of a translocation component and ATP hydrolyzing module and a substrate-capture (S) component. Here, we present the crystal structure of YkoE from Bacillus subtilis, the S component of the previously uncharacterized group I ECF transporter YkoEDC. Structural and biochemical analyses revealed the constituent residues of the thiamine-binding pocket as well as an unexpected mode of vitamin recognition. In addition, our experimental and bioinformatics data demonstrate major differences between YkoE and group II ECF transporters and indicate how group I vitamin transporter S components have diverged from other group I and group II ECF transporters. The crystal structure of a group I ECF transporter S component was determined The thiamine-bound structure was determined in lipidic environment The structure reveals major differences to group II S components CGMD simulations indicate the orientation of the protein in the membrane
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Finkenwirth F, Kirsch F, Eitinger T. Complex Stability During the Transport Cycle of a Subclass I ECF Transporter. Biochemistry 2017; 56:4578-4583. [DOI: 10.1021/acs.biochem.7b00390] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Friedrich Finkenwirth
- Institut für Biologie/Mikrobiologie, Humboldt-Universität zu Berlin, Unter den Linden 6, 10099 Berlin, Germany
| | - Franziska Kirsch
- Institut für Biologie/Mikrobiologie, Humboldt-Universität zu Berlin, Unter den Linden 6, 10099 Berlin, Germany
| | - Thomas Eitinger
- Institut für Biologie/Mikrobiologie, Humboldt-Universität zu Berlin, Unter den Linden 6, 10099 Berlin, Germany
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42
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Computational studies of membrane proteins: from sequence to structure to simulation. Curr Opin Struct Biol 2017; 45:133-141. [DOI: 10.1016/j.sbi.2017.04.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Revised: 04/07/2017] [Accepted: 04/07/2017] [Indexed: 11/19/2022]
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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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Swier LJYM, Monjas L, Reeßing F, Oudshoorn RC, Aisyah, Primke T, Bakker MM, van Olst E, Ritschel T, Faustino I, Marrink SJ, Hirsch AKH, Slotboom DJ. Insight into the complete substrate-binding pocket of ThiT by chemical and genetic mutations. MEDCHEMCOMM 2017; 8:1121-1130. [PMID: 30108823 DOI: 10.1039/c7md00079k] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Accepted: 03/24/2017] [Indexed: 01/12/2023]
Abstract
Energy-coupling factor (ECF) transporters are involved in the uptake of micronutrients in bacteria. The transporters capture the substrate by high-affinity binding proteins, the so-called S-components. Here, we present the analysis of two regions of the substrate-binding pocket of the thiamine-specific S-component in Lactococcus lactis, ThiT. First, interaction of the thiazolium ring of thiamine with residues Trp34, His125 and Glu84 by π-π-stacking and cation-π is studied, and second, the part of the binding pocket that extends from the hydroxyl group. We mutated either the transported ligand (chemically) or the protein (genetically). Surprisingly, modifications in the thiazolium ring by introducing substituents with opposite electronic effects had similar effects on the binding affinity. We hypothesize that the electronic effects are superseeded by steric effects of the added substituents, which renders the study of isolated interactions difficult. Amino acid substitutions in ThiT indicate that the electrostatic interaction facilitated by residue Glu84 of ThiT and thiamine is necessary for picomolar affinity. Deazathiamine derivatives that explore the subpocket of the binding site extending from the hydroxyl group of thiamine bind with high affinity to ThiT and may be developed into selective inhibitors of thiamine transport by ECF transporters. Molecular-dynamics simulations suggest that two of these derivatives may not only bind to ThiT, but could also be transported.
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Affiliation(s)
- L J Y M Swier
- Groningen Biomolecular Sciences and Biotechnology Institute , University of Groningen , Nijenborgh 4 , 9747 AG Groningen , The Netherlands . ; Tel: +31 50 363 4187
| | - L Monjas
- Stratingh Institute for Chemistry , University of Groningen , Nijenborgh 7 , 9747 AG Groningen , The Netherlands . ; Tel: +31 50 363 4275
| | - F Reeßing
- Stratingh Institute for Chemistry , University of Groningen , Nijenborgh 7 , 9747 AG Groningen , The Netherlands . ; Tel: +31 50 363 4275
| | - R C Oudshoorn
- Groningen Biomolecular Sciences and Biotechnology Institute , University of Groningen , Nijenborgh 4 , 9747 AG Groningen , The Netherlands . ; Tel: +31 50 363 4187
| | - Aisyah
- Groningen Biomolecular Sciences and Biotechnology Institute , University of Groningen , Nijenborgh 4 , 9747 AG Groningen , The Netherlands . ; Tel: +31 50 363 4187
| | - T Primke
- Groningen Biomolecular Sciences and Biotechnology Institute , University of Groningen , Nijenborgh 4 , 9747 AG Groningen , The Netherlands . ; Tel: +31 50 363 4187
| | - M M Bakker
- Stratingh Institute for Chemistry , University of Groningen , Nijenborgh 7 , 9747 AG Groningen , The Netherlands . ; Tel: +31 50 363 4275
| | - E van Olst
- Groningen Biomolecular Sciences and Biotechnology Institute , University of Groningen , Nijenborgh 4 , 9747 AG Groningen , The Netherlands . ; Tel: +31 50 363 4187
| | - T Ritschel
- Centre for Molecular and Biomolecular Informatics (CMBI) , Radboudumc , 6525 GA Nijmegen , The Netherlands
| | - I Faustino
- Groningen Biomolecular Sciences and Biotechnology Institute , University of Groningen , Nijenborgh 4 , 9747 AG Groningen , The Netherlands . ; Tel: +31 50 363 4187
| | - S J Marrink
- Groningen Biomolecular Sciences and Biotechnology Institute , University of Groningen , Nijenborgh 4 , 9747 AG Groningen , The Netherlands . ; Tel: +31 50 363 4187
| | - A K H Hirsch
- Stratingh Institute for Chemistry , University of Groningen , Nijenborgh 7 , 9747 AG Groningen , The Netherlands . ; Tel: +31 50 363 4275
| | - D J Slotboom
- Groningen Biomolecular Sciences and Biotechnology Institute , University of Groningen , Nijenborgh 4 , 9747 AG Groningen , The Netherlands . ; Tel: +31 50 363 4187
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Lewinson O, Livnat-Levanon N. Mechanism of Action of ABC Importers: Conservation, Divergence, and Physiological Adaptations. J Mol Biol 2017; 429:606-619. [PMID: 28104364 DOI: 10.1016/j.jmb.2017.01.010] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Revised: 01/03/2017] [Accepted: 01/04/2017] [Indexed: 01/08/2023]
Abstract
The past decade has seen a remarkable surge in structural characterization of ATP binding cassette (ABC) transporters, which have spurred a more focused functional analysis of these elaborate molecular machines. As a result, it has become increasingly apparent that there is a substantial degree of mechanistic variation between ABC transporters that function as importers, which correlates with their physiological roles. Here, we summarize recent advances in ABC importers' structure-function studies and provide an explanation as to the origin of the different mechanisms of action.
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Affiliation(s)
- Oded Lewinson
- Department of Biochemistry, The Bruce and Ruth Rappaport Faculty of Medicine, The Technion-Israel Institute of Technology, 31096 Haifa, Israel.
| | - Nurit Livnat-Levanon
- Department of Biochemistry, The Bruce and Ruth Rappaport Faculty of Medicine, The Technion-Israel Institute of Technology, 31096 Haifa, Israel
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Karpowich NK, Song J, Wang DN. An Aromatic Cap Seals the Substrate Binding Site in an ECF-Type S Subunit for Riboflavin. J Mol Biol 2016; 428:3118-30. [PMID: 27312125 DOI: 10.1016/j.jmb.2016.06.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Revised: 06/07/2016] [Accepted: 06/07/2016] [Indexed: 10/21/2022]
Abstract
ECF transporters are a family of active membrane transporters for essential micronutrients, such as vitamins and trace metals. Found exclusively in archaea and bacteria, these transporters are composed of four subunits: an integral membrane substrate-binding subunit (EcfS), a transmembrane coupling subunit (EcfT), and two ATP-binding cassette ATPases (EcfA and EcfA'). We have characterized the structural basis of substrate binding by the EcfS subunit for riboflavin from Thermotoga maritima, TmRibU. TmRibU binds riboflavin with high affinity, and the protein-substrate complex is exceptionally stable in solution. The crystal structure of riboflavin-bound TmRibU reveals an electronegative binding pocket at the extracellular surface in which the substrate is completely buried. Analysis of the intermolecular contacts indicates that nearly every available substrate hydrogen bond is satisfied. A conserved aromatic residue at the extracellular end of TM5, Tyr130, caps the binding site to generate a substrate-bound, occluded state, and non-conservative mutation of Tyr130 reduces the stability of this conformation. Using a novel fluorescence binding assay, we find that an aromatic residue at this position is essential for high-affinity substrate binding. Comparison with other S subunit structures suggests that TM5 and Loop5-6 contain a dynamic, conserved motif that plays a key role in gating substrate entry and release by S subunits of ECF transporters.
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Affiliation(s)
- Nathan K Karpowich
- The Helen L. and Martin S. Kimmel Center for Biology and Medicine at the Skirball Institute of Biomolecular Medicine, and Department of Cell Biology, New York University School of Medicine, 540 First Avenue, New York, NY 10016, USA.
| | - Jinmei Song
- The Helen L. and Martin S. Kimmel Center for Biology and Medicine at the Skirball Institute of Biomolecular Medicine, and Department of Cell Biology, New York University School of Medicine, 540 First Avenue, New York, NY 10016, USA
| | - Da-Neng Wang
- The Helen L. and Martin S. Kimmel Center for Biology and Medicine at the Skirball Institute of Biomolecular Medicine, and Department of Cell Biology, New York University School of Medicine, 540 First Avenue, New York, NY 10016, USA.
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