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Kienlein M, Zacharias M. How arginine inhibits substrate-binding domain 2 elucidated using molecular dynamics simulations. Protein Sci 2024; 33:e5077. [PMID: 38888275 PMCID: PMC11184577 DOI: 10.1002/pro.5077] [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: 02/08/2024] [Revised: 04/19/2024] [Accepted: 05/28/2024] [Indexed: 06/20/2024]
Abstract
The substrate-binding domain 2 (SBD2) is an important part of the bacterial glutamine (GLN) transporter and mediates binding and delivery of GLN to the transporter translocation subunit. The SBD2 consists of two domains, D1 and D2, that bind GLN in the space between domains in a closed structure. In the absence of ligand, the SBD2 adopts an open conformation with larger space between domains. The GLN binding and closing are essential for the subsequent transport into the cell. Arginine (ARG) can also bind to SBD2 but does not induce closing and inhibits GLN transport. We use atomistic molecular dynamics (MD) simulations in explicit solvent to study ARG binding in the presence of the open SBD2 structure and observed reversible binding to the native GLN binding site with similar contacts but no transition to a closed SBD2 state. Absolute binding free energy simulations predict a considerable binding affinity of ARG and GLN to the binding site on the D1 domain. Free energy simulations to induce subsequent closing revealed a strong free energy penalty in case of ARG binding in contrast to GLN binding that favors the closed SBD2 state but still retains a free energy barrier for closing. The simulations allowed the identification of the molecular origin of the closing penalty in case of bound ARG and suggested a mutation of lysine at position 373 to alanine that strongly reduced the penalty and allowed closing even in the presence of bound ARG. The study offers an explanation of the molecular mechanism of how ARG competitively inhibits GLN from binding to SBD2 and from triggering the transition to a closed conformation. The proposed Lys373Ala mutation shows promise as a potential tool to validate whether a conformational mismatch between open SBD2 and the translocator is responsible for preventing ARG uptake to the cell.
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Affiliation(s)
- Maximilian Kienlein
- Center for Functional Protein Assemblies (CPA)Technical University of MunichGarchingGermany
| | - Martin Zacharias
- Center for Functional Protein Assemblies (CPA)Technical University of MunichGarchingGermany
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2
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Takemiya K, Wang S, Liu Y, Murthy N, Goodman MM, Taylor WR. Isothermal titration calorimetry analysis of the binding between the maltodextrin binding protein malE of Staphylococcus aureus with maltodextrins of various lengths. Biochem Biophys Res Commun 2024; 695:149467. [PMID: 38211531 PMCID: PMC10842747 DOI: 10.1016/j.bbrc.2023.149467] [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: 09/05/2023] [Revised: 12/12/2023] [Accepted: 12/30/2023] [Indexed: 01/13/2024]
Abstract
Staphylococcus aureus (S. aureus), a Gram-positive bacterium, causes a wide range of infections, and diagnosis at an early stage is challenging. Targeting the maltodextrin transporter has emerged as a promising strategy for imaging bacteria and has been able to image a wide range of bacteria including S. aureus. However, little is known about the maltodextrin transporter in S. aureus, and this prevents new S. aureus specific ligands for the maltodextrin transporter from being developed. In Gram-positive bacteria, including S. aureus, the first step of maltodextrin transport is the binding of the maltodextrin-binding protein malE to maltodextrins. Thus, understanding the binding affinity and characteristics of malE from S. aureus is important to developing efficient maltodextrin-based imaging probes. We evaluated the affinity of malE of S. aureus to maltodextrins of various lengths. MalE of S. aureus (SAmalE) was expressed in E. coli BL21(DE3) and purified by Ni-NTA resin. The affinities of SAmalE to maltodextrins were evaluated with isothermal titration calorimetry. SAmalE has low affinity to maltose but binds to maltotriose and longer maltodextrins up to maltoheptaose with affinities up to Ka = 9.02 ± 0.49 × 105 M-1. SAmalE binding to maltotriose-maltoheptaose was exothermic and fit a single-binding site model. The van't Hoff enthalpy in the binding reaction of SAmalE with maltotriose was 9.9 ± 1.3 kcal/mol, and the highest affinity of SAmalE was observed with maltotetraose with Ka = 9.02 ± 0.49 × 105 M-1. In the plot of ΔH-T*ΔS, the of Enthalpy-Entropy Compensation effect was observed in binding reaction of SAmalE to maltodextrins. Acarbose and maltotetraiol bind with SAmalE indicating that SAmalE is tolerant of modifications on both the reducing and non-reducing ends of maltodextrins. Our results show that unlike ECmalE and similar to the maltodextrin binding protein of Streptococci, SAmalE primarily binds to maltodextrins via hydrogen bonds. This is distinct from the maltodextrin binding protein of Streptococci, SAmalE that binds to maltotetraiol with high affinity. Understanding the binding characteristics and tolerance to maltodextrins modifications by maltodextrin binding proteins will hopefully provide the basis for developing bacterial species-specific maltodextrin-based imaging probes.
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Affiliation(s)
- Kiyoko Takemiya
- Division of Cardiology, Department of Medicine, Emory University School of Medicine, 1750 Haygood Dr. NE, Atlanta, GA, 30322, USA.
| | - Shelly Wang
- Division of Cardiology, Department of Medicine, Emory University School of Medicine, 1750 Haygood Dr. NE, Atlanta, GA, 30322, USA
| | - Yu Liu
- Division of Cardiology, Department of Medicine, Emory University School of Medicine, 1750 Haygood Dr. NE, Atlanta, GA, 30322, USA
| | - Niren Murthy
- Department of Bioengineering, Stanley Hall 306 University of California at Berkeley, Berkeley, CA, 94720, USA
| | - Mark M Goodman
- Department of Radiology and Imaging Sciences, School of Medicine, Emory University, 1364 Clifton Road NE, Atlanta, GA, 30322, USA; Center for Systems Imaging, Emory University, 1364 Clifton Rd NE, Atlanta, 30322, Georgia
| | - W Robert Taylor
- Division of Cardiology, Department of Medicine, Emory University School of Medicine, 1750 Haygood Dr. NE, Atlanta, GA, 30322, USA; Joseph Maxwell Cleland Atlanta VA Medical Center, 1670 Clairmont Road, Decatur, GA, 30033, USA; Wallace H. Coulter Department of Biomedical Engineering School of Medicine, Emory University, 1750 Haygood Dr. NE, Atlanta, GA, 30322, USA
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3
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Davies JS, Currie MJ, Dobson RCJ, Horne CR, North RA. TRAPs: the 'elevator-with-an-operator' mechanism. Trends Biochem Sci 2024; 49:134-144. [PMID: 38102017 DOI: 10.1016/j.tibs.2023.11.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Revised: 11/18/2023] [Accepted: 11/21/2023] [Indexed: 12/17/2023]
Abstract
Tripartite ATP-independent periplasmic (TRAP) transporters are nutrient-uptake systems found in bacteria and archaea. These evolutionary divergent transporter systems couple a substrate-binding protein (SBP) to an elevator-type secondary transporter, which is a first-of-its-kind mechanism of transport. Here, we highlight breakthrough TRAP transporter structures and recent functional data that probe the mechanism of transport. Furthermore, we discuss recent structural and biophysical studies of the ion transporter superfamily (ITS) members and highlight mechanistic principles that are relevant for further exploration of the TRAP transporter system.
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Affiliation(s)
- James S Davies
- Department of Biochemistry and Biophysics, Stockholm University, 106 91 Stockholm, Sweden
| | - Michael J Currie
- Biomolecular Interaction Centre, Maurice Wilkins Centre for Biodiscovery, MacDiarmid Institute for Advanced Materials and Nanotechnology, Christchurch 8140, New Zealand; School of Biological Sciences, University of Canterbury, Christchurch 8140, New Zealand
| | - Renwick C J Dobson
- Biomolecular Interaction Centre, Maurice Wilkins Centre for Biodiscovery, MacDiarmid Institute for Advanced Materials and Nanotechnology, Christchurch 8140, New Zealand; School of Biological Sciences, University of Canterbury, Christchurch 8140, New Zealand; Bio21 Molecular Science and Biotechnology Institute, Department of Biochemistry and Pharmacology, University of Melbourne, Parkville, VIC 3010, Australia
| | - Christopher R Horne
- Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, VIC 3052, Australia; Department of Medical Biology, University of Melbourne, Parkville, VIC 3052, Australia; Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Parkville, VIC 3052, Australia.
| | - Rachel A North
- Department of Biochemistry and Biophysics, Stockholm University, 106 91 Stockholm, Sweden; School of Medical Sciences, Faculty of Medicine and Health, University of Sydney, Sydney, NSW 2006, Australia.
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4
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Tjo H, Conway JM. Sugar transport in thermophiles: Bridging lignocellulose deconstruction and bioconversion. J Ind Microbiol Biotechnol 2024; 51:kuae020. [PMID: 38866721 PMCID: PMC11212667 DOI: 10.1093/jimb/kuae020] [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: 03/14/2024] [Accepted: 06/11/2024] [Indexed: 06/14/2024]
Abstract
Biomass degrading thermophiles play an indispensable role in building lignocellulose-based supply chains. They operate at high temperatures to improve process efficiencies and minimize mesophilic contamination, can overcome lignocellulose recalcitrance through their native carbohydrate-active enzyme (CAZyme) inventory, and can utilize a wide range of sugar substrates. However, sugar transport in thermophiles is poorly understood and investigated, as compared to enzymatic lignocellulose deconstruction and metabolic conversion of sugars to value-added chemicals. Here, we review the general modes of sugar transport in thermophilic bacteria and archaea, covering the structural, molecular, and biophysical basis of their high-affinity sugar uptake. We also discuss recent genetic studies on sugar transporter function. With this understanding of sugar transport, we discuss strategies for how sugar transport can be engineered in thermophiles, with the potential to enhance the conversion of lignocellulosic biomass into renewable products. ONE-SENTENCE SUMMARY Sugar transport is the understudied link between extracellular biomass deconstruction and intracellular sugar metabolism in thermophilic lignocellulose bioprocessing.
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Affiliation(s)
- Hansen Tjo
- Department of Chemical & Biological Engineering, Princeton University, Princeton, NJ 08544, USA
| | - Jonathan M Conway
- Department of Chemical & Biological Engineering, Princeton University, Princeton, NJ 08544, USA
- Omenn-Darling Bioengineering Institute, Princeton University, Princeton, NJ 08544, USA
- Andlinger Center for Energy and the Environment, Princeton University, Princeton, NJ 08544, USA
- High Meadows Environmental Institute, Princeton University, Princeton, NJ 08544, USA
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5
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Liyanage SH, Yan M. Maltose-Derivatized Fluorescence Turn-On Imaging Probe for Bacteria Detection. ACS Infect Dis 2023; 9:2560-2571. [PMID: 37936289 DOI: 10.1021/acsinfecdis.3c00403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2023]
Abstract
We report a maltose-derivatized fluorescence turn-on imaging probe, Mal-Cz, to detect E. coli and Staphylococci. The fluorescence turn-on is achieved through an intramolecular C-H insertion reaction of the perfluoroaryl azide-functionalized carbazole to give a fluorescent product. Confocal fluorescence microscopy confirmed the successful uptake of Mal-Cz by E. coli and Staphylococci upon photoactivation. The Mal-Cz probe could selectively detect E. coli and S. epidermidis in the presence of P. aeruginosa and M. smegmatis without interference from these bacteria. Both the photoactivation and bacteria detection can be accomplished using a hand-held UV lamp at 365 nm, with the limit of detection of 103 CFU/mL by the naked eye. Mal-Cz could also be used to detect E. coli and S. epidermidis spiked in milk by the naked eye under a hand-held UV lamp. The uptake of Mal-Cz requires metabolically active bacteria: the uptake was reduced in stationary phase bacteria and was diminished in bacteria that were killed by heating or treating with antibiotics or sodium azide. The uptake decreased with increasing concentration of added free maltose, indicating that Mal-Cz hijacked the maltose uptake pathways. In E. coli, the maltose transport systems, including maltoporin LamB, maltose binding protein MBP, and the maltose ATP binding cassette (ABC) transporter MalFGK2, are all critical for the transport of Mal-Cz. The uptake was diminished in the deletion mutants ΔLamB, ΔMalE, ΔMalF, and ΔMalK.
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Affiliation(s)
- Sajani H Liyanage
- Department of Chemistry, University of Massachusetts Lowell, Lowell, Massachusetts 01854, United States
| | - Mingdi Yan
- Department of Chemistry, University of Massachusetts Lowell, Lowell, Massachusetts 01854, United States
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Liang J, Yang X, Hu T, Gao Y, Yang Q, Yang H, Peng W, Zhou X, Guddat LW, Zhang B, Rao Z, Liu F. Structural insights into trehalose capture and translocation by mycobacterial LpqY-SugABC. Structure 2023; 31:1158-1165.e3. [PMID: 37619560 DOI: 10.1016/j.str.2023.07.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 06/25/2023] [Accepted: 07/28/2023] [Indexed: 08/26/2023]
Abstract
The human pathogen, Mycobacterium tuberculosis (Mtb) relies heavily on trehalose for both survival and pathogenicity. The type I ATP-binding cassette (ABC) transporter LpqY-SugABC is the only trehalose import pathway in Mtb. Conformational dynamics of ABC transporters is an important feature to explain how they operate, but experimental structures are determined in a static environment. Therefore, a detailed transport mechanism cannot be elucidated because there is a lack of intermediate structures. Here, we used single-particle cryo-electron microscopy (cryo-EM) to determine the structure of the Mycobacterium smegmatis (M. smegmatis) trehalose-specific importer LpqY-SugABC complex in five different conformations. These structures have been classified and reconstructed from a single cryo-EM dataset. This study allows a comprehensive understanding of the trehalose recycling mechanism in Mycobacteria and also demonstrates the potential of single-particle cryo-EM to explore the dynamic structures of other ABC transporters and molecular machines.
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Affiliation(s)
- Jingxi Liang
- State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin, China; Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology, ShanghaiTech University, Shanghai, China; Innovative Center for Pathogen Research, Guangzhou Laboratory, Guangzhou, China
| | - Xiuna Yang
- Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology, ShanghaiTech University, Shanghai, China
| | - Tianyu Hu
- Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology, ShanghaiTech University, Shanghai, China
| | - Yan Gao
- Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology, ShanghaiTech University, Shanghai, China
| | - Qi Yang
- Innovative Center for Pathogen Research, Guangzhou Laboratory, Guangzhou, China
| | - Haitao Yang
- Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology, ShanghaiTech University, Shanghai, China
| | - Wei Peng
- Innovative Center for Pathogen Research, Guangzhou Laboratory, Guangzhou, China
| | - Xiaoting Zhou
- The State Key Laboratory of Reproductive Regulation and Breeding of Grassland Livestock, School of Life Sciences, Inner Mongolia University, Hohhot, China
| | - Luke W Guddat
- School of Chemistry and Molecular Biosciences, the University of Queensland, Brisbane, QLD, Australia
| | - Bing Zhang
- Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology, ShanghaiTech University, Shanghai, China.
| | - Zihe Rao
- State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin, China; Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology, ShanghaiTech University, Shanghai, China; Innovative Center for Pathogen Research, Guangzhou Laboratory, Guangzhou, China; National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, CAS, Beijing, China; Laboratory of Structural Biology, Tsinghua University, Beijing, China.
| | - Fengjiang Liu
- Innovative Center for Pathogen Research, Guangzhou Laboratory, Guangzhou, China.
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7
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Aranda-Caraballo J, Saenz RA, López-Zavala AA, Velazquez-Cruz B, Espinosa-Barrera L, Cárdenas-Conejo Y, Zárate-Romero A, Linares-Vergara O, Osuna-Castro JA, Bonales-Alatorre E, Centeno-Leija S, Serrano-Posada H. Binding Specificity of a Novel Cyclo/Maltodextrin-Binding Protein and Its Role in the Cyclodextrin ABC Importer System from Thermoanaerobacterales. Molecules 2023; 28:6080. [PMID: 37630332 PMCID: PMC10458862 DOI: 10.3390/molecules28166080] [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: 07/24/2023] [Revised: 08/11/2023] [Accepted: 08/13/2023] [Indexed: 08/27/2023] Open
Abstract
Extracellular synthesis of functional cyclodextrins (CDs) as intermediates of starch assimilation is a convenient microbial adaptation to sequester substrates, increase the half-life of the carbon source, carry bioactive compounds, and alleviate chemical toxicity through the formation of CD-guest complexes. Bacteria encoding the four steps of the carbohydrate metabolism pathway via cyclodextrins (CM-CD) actively internalize CDs across the microbial membrane via a putative type I ATP-dependent ABC sugar importer system, MdxEFG-(X/MsmX). While the first step of the CM-CD pathway encompasses extracellular starch-active cyclomaltodextrin glucanotransferases (CGTases) to synthesize linear dextrins and CDs, it is the ABC importer system in the second step that is the critical factor in determining which molecules from the CGTase activity will be internalized by the cell. Here, structure-function relationship studies of the cyclo⁄maltodextrin-binding protein MdxE of the MdxEFG-MsmX importer system from Thermoanaerobacter mathranii subsp. mathranii A3 are presented. Calorimetric and fluorescence studies of recombinant MdxE using linear dextrins and CDs showed that although MdxE binds linear dextrins and CDs with high affinity, the open-to-closed conformational change is solely observed after α- and β-CD binding, suggesting that the CM-CD pathway from Thermoanaerobacterales is exclusive for cellular internalization of these molecules. Structural analysis of MdxE coupled with docking simulations showed an overall architecture typically found in sugar-binding proteins (SBPs) that comprised two N- and C-domains linked by three small hinge regions, including the conserved aromatic triad Tyr193/Trp269/Trp378 in the C-domain and Phe87 in the N-domain involved in CD recognition and stabilization. Structural bioinformatic analysis of the entire MdxFG-MsmX importer system provided further insights into the binding, internalization, and delivery mechanisms of CDs. Hence, while the MdxE-CD complex couples to the permease subunits MdxFG to deliver the CD into the transmembrane channel, the dimerization of the cytoplasmatic promiscuous ATPase MsmX triggers active transport into the cytoplasm. This research provides the first results on a novel thermofunctional SBP and its role in the internalization of CDs in extremely thermophilic bacteria.
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Affiliation(s)
- Jorge Aranda-Caraballo
- Laboratorio de Biología Sintética, Estructural y Molecular, Universidad de Colima, Carretera Los Limones-Loma de Juárez, Colima 28627, Mexico; (J.A.-C.); (B.V.-C.); (L.E.-B.); (O.L.-V.)
| | - Roberto A. Saenz
- Facultad de Ciencias, Universidad de Colima, Bernal Díaz del Castillo 340, Colima 28045, Mexico;
| | - Alonso A. López-Zavala
- Departamento de Ciencias Químico-Biológicas, Universidad de Sonora, Hermosillo 83000, Mexico;
| | - Beatriz Velazquez-Cruz
- Laboratorio de Biología Sintética, Estructural y Molecular, Universidad de Colima, Carretera Los Limones-Loma de Juárez, Colima 28627, Mexico; (J.A.-C.); (B.V.-C.); (L.E.-B.); (O.L.-V.)
| | - Laura Espinosa-Barrera
- Laboratorio de Biología Sintética, Estructural y Molecular, Universidad de Colima, Carretera Los Limones-Loma de Juárez, Colima 28627, Mexico; (J.A.-C.); (B.V.-C.); (L.E.-B.); (O.L.-V.)
| | - Yair Cárdenas-Conejo
- Consejo Nacional de Humanidades, Ciencias y Tecnologías, Laboratorio de Biología Sintética, Estructural y Molecular, Universidad de Colima, Carretera Los Limones-Loma de Juárez, Colima 28627, Mexico;
| | - Andrés Zárate-Romero
- Consejo Nacional de Humanidades, Ciencias y Tecnologías, Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México, Km 107 CarreteraTijuana-Ensenada, Ensenada 22860, Mexico;
| | - Oscar Linares-Vergara
- Laboratorio de Biología Sintética, Estructural y Molecular, Universidad de Colima, Carretera Los Limones-Loma de Juárez, Colima 28627, Mexico; (J.A.-C.); (B.V.-C.); (L.E.-B.); (O.L.-V.)
| | - Juan A. Osuna-Castro
- Facultad de Ciencias Biológicas y Agropecuarias, Universidad de Colima, Autopista Colima-Manzanillo, Tecomán 28100, Mexico;
| | - Edgar Bonales-Alatorre
- Centro Universitario de Investigaciones Biomédicas, Universidad de Colima, Avenida 25 de julio 965, Colonia Villa de San Sebastián, Colima 28045, Mexico;
| | - Sara Centeno-Leija
- Consejo Nacional de Humanidades, Ciencias y Tecnologías, Laboratorio de Biología Sintética, Estructural y Molecular, Universidad de Colima, Carretera Los Limones-Loma de Juárez, Colima 28627, Mexico;
| | - Hugo Serrano-Posada
- Consejo Nacional de Humanidades, Ciencias y Tecnologías, Laboratorio de Biología Sintética, Estructural y Molecular, Universidad de Colima, Carretera Los Limones-Loma de Juárez, Colima 28627, Mexico;
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8
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Campbell E, Jordan C, Gilmour R. Fluorinated carbohydrates for 18F-positron emission tomography (PET). Chem Soc Rev 2023; 52:3599-3626. [PMID: 37171037 PMCID: PMC10243284 DOI: 10.1039/d3cs00037k] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Indexed: 05/13/2023]
Abstract
Carbohydrate diversity is foundational in the molecular literacy that regulates cellular function and communication. Consequently, delineating and leveraging this structure-function interplay continues to be a core research objective in the development of candidates for biomedical diagnostics. A totemic example is the ubiquity of 2-deoxy-2-[18F]-fluoro-D-glucose (2-[18F]-FDG) as a radiotracer for positron emission tomography (PET), in which metabolic trapping is harnessed. Building on this clinical success, more complex sugars with unique selectivities are gaining momentum in molecular recognition and personalised medicine: this reflects the opportunities that carbohydrate-specific targeting affords in a broader sense. In this Tutorial Review, key milestones in the development of 2-[18F]-FDG and related glycan-based radiotracers for PET are described, with their diagnostic functions, to assist in navigating this rapidly expanding field of interdisciplinary research.
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Affiliation(s)
- Emma Campbell
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster Corrensstraße 36, 48149, Münster, Germany.
- Cells in Motion Interfaculty Centre, Westfälische Wilhelms-Universität Münster, Röntgenstraße 16, 48149, Münster, Germany
| | - Christina Jordan
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster Corrensstraße 36, 48149, Münster, Germany.
- Cells in Motion Interfaculty Centre, Westfälische Wilhelms-Universität Münster, Röntgenstraße 16, 48149, Münster, Germany
| | - Ryan Gilmour
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster Corrensstraße 36, 48149, Münster, Germany.
- Cells in Motion Interfaculty Centre, Westfälische Wilhelms-Universität Münster, Röntgenstraße 16, 48149, Münster, Germany
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9
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Borovsky D, Rougé P, Shatters RG. Bactericidal Properties of Proline-Rich Aedes aegypti Trypsin Modulating Oostatic Factor ( AeaTMOF). LIFE (BASEL, SWITZERLAND) 2022; 13:life13010019. [PMID: 36675967 PMCID: PMC9862690 DOI: 10.3390/life13010019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Revised: 12/16/2022] [Accepted: 12/19/2022] [Indexed: 12/24/2022]
Abstract
The antimicrobial properties of proline-rich Aedes aegypti decapeptide TMOF (AeaTMOF) and oncocin112 (1-13) were compared. Incubations with multidrug-resistant Escherichia coli cells showed that AeaTMOF (5 mM) was able to completely inhibit bacterial cell growth, whereas oncocin112 (1-13) (20 mM) partially inhibited bacterial growth as compared with bacterial cells that were not multidrug-resistant cells. AeaTMOF (5 mM) was very effective against Acinetobacter baumannii and Pseudomonas aeruginosa, completely inhibiting cell growth during 15 h incubations. AeaTMOF (5 mM) completely inhibited the Gram-positive bacteria Staphylococcus aureus and Bacillus thurengiensis sups. Israelensis cell growth, whereas oncocin112 (1-13) (10 and 20 mM) failed to affect bacterial cell growth. E. coli cells that lack the SbmA transporter were inhibited by AeaTMOF (5 mM) and not by oncocin112 (1-13) (10 to 20 mM), indicating that AeaTMOF can use other bacterial transporters than SbmA that is mainly used by proline-rich antimicrobial peptides. Incubation of E. coli cells with NaAzide showed that AeaTMOF does not use ABC-like transporters that use ATP hydrolysis to import molecules into bacterial cells. Three-dimensional modeling and docking of AeaTMOF to SbmA and MdtM transporters showed that AeaTMOF can bind these proteins, and the binding location of AeaTMOF inside these protein transporters allows AeaTMOF to be transported into the bacterial cytosol. These results show that AeaTMOF can be used as a future antibacterial agent against both multidrug-resistant Gram-positive and -negative bacteria.
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Affiliation(s)
- Dov Borovsky
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
- Correspondence:
| | - Pierre Rougé
- Faculte des Sciences Pharmaceutiques, 3106 Toulouse, France
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10
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Zhao Z, Rudman NA, He J, Dmochowski IJ. Programming xenon diffusion in maltose-binding protein. Biophys J 2022; 121:4635-4643. [PMID: 36271622 PMCID: PMC9748359 DOI: 10.1016/j.bpj.2022.10.025] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 10/12/2022] [Accepted: 10/17/2022] [Indexed: 12/15/2022] Open
Abstract
Protein interiors contain void space that can bind small gas molecules. Determination of gas pathways and kinetics in proteins has been an intriguing and challenging task. Here, we combined computational methods and the hyperpolarized xenon-129 chemical exchange saturation transfer (hyper-CEST) NMR technique to investigate xenon (Xe) exchange kinetics in maltose-binding protein (MBP). A salt bridge ∼9 Å from the Xe-binding site formed upon maltose binding and slowed the Xe exchange rate, leading to a hyper-CEST 129Xe signal from maltose-bound MBP. Xe dissociation occurred faster than dissociation of the salt bridge, as shown by 13C NMR spectroscopy and variable-B1 hyper-CEST experiments. "Xe flooding" molecular dynamics simulations identified a surface hydrophobic site, V23, that has good Xe binding affinity. Mutations at this site confirmed its role as a secondary exchange pathway in modulating Xe diffusion. This shows the possibility for site-specifically controlling xenon protein-solvent exchange. Analysis of the available MBP structures suggests a biological role of MBP's large hydrophobic cavity to accommodate structural changes associated with ligand binding and protein-protein interactions.
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Affiliation(s)
- Zhuangyu Zhao
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Nathan A Rudman
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Jiayi He
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Ivan J Dmochowski
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania.
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11
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Novel functional insights into a modified sugar-binding protein from Synechococcus MITS9220. Sci Rep 2022; 12:4805. [PMID: 35314715 PMCID: PMC8938411 DOI: 10.1038/s41598-022-08459-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 03/07/2022] [Indexed: 11/17/2022] Open
Abstract
Paradigms of metabolic strategies employed by photoautotrophic marine picocyanobacteria have been challenged in recent years. Based on genomic annotations, picocyanobacteria are predicted to assimilate organic nutrients via ATP-binding cassette importers, a process mediated by substrate-binding proteins. We report the functional characterisation of a modified sugar-binding protein, MsBP, from a marine Synechococcus strain, MITS9220. Ligand screening of MsBP shows a specific affinity for zinc (KD ~ 1.3 μM) and a preference for phosphate-modified sugars, such as fructose-1,6-biphosphate, in the presence of zinc (KD ~ 5.8 μM). Our crystal structures of apo MsBP (no zinc or substrate-bound) and Zn-MsBP (with zinc-bound) show that the presence of zinc induces structural differences, leading to a partially-closed substrate-binding cavity. The Zn-MsBP structure also sequesters several sulphate ions from the crystallisation condition, including two in the binding cleft, appropriately placed to mimic the orientation of adducts of a biphosphate hexose. Combined with a previously unseen positively charged binding cleft in our two structures and our binding affinity data, these observations highlight novel molecular variations on the sugar-binding SBP scaffold. Our findings lend further evidence to a proposed sugar acquisition mechanism in picocyanobacteria alluding to a mixotrophic strategy within these ubiquitous photosynthetic bacteria.
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12
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Suginta W, Sanram S, Aunkham A, Winterhalter M, Schulte A. The C2 entity of chitosugars is crucial in molecular selectivity of the Vibrio campbellii chitoporin. J Biol Chem 2021; 297:101350. [PMID: 34715124 PMCID: PMC8608610 DOI: 10.1016/j.jbc.2021.101350] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 10/21/2021] [Accepted: 10/22/2021] [Indexed: 12/14/2022] Open
Abstract
The marine bacterium Vibrio campbellii expresses a chitooligosaccharide-specific outer-membrane channel (chitoporin) for the efficient uptake of nutritional chitosugars that are externally produced through enzymic degradation of environmental host shell chitin. However, the principles behind the distinct substrate selectivity of chitoporins are unclear. Here, we employed black lipid membrane (BLM) electrophysiology, which handles the measurement of the flow of ionic current through porins in phospholipid bilayers for the assessment of porin conductivities, to investigate the pH dependency of chitosugar-chitoporin interactions for the bacterium's natural substrate chitohexaose and its deacetylated form, chitosan hexaose. We show that efficient passage of the N-acetylated chitohexaose through the chitoporin is facilitated by its strong affinity for the pore. In contrast, the deacetylated chitosan hexaose is impermeant; however, protonation of the C2 amino entities of chitosan hexaose allows it to be pulled through the channel in the presence of a transmembrane electric field. We concluded from this the crucial role of C2-substitution as the determining factor for chitoporin entry. A change from N-acetylamino- to amino-substitution effectively abolished the ability of approaching molecules to enter the chitoporin, with deacetylation leading to loss of the distinctive structural features of nanopore opening and pore access of chitosugars. These findings provide further understanding of the multistep pathway of chitin utilization by marine Vibrio bacteria and may guide the development of solid-state or genetically engineered biological nanopores for relevant technological applications.
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Affiliation(s)
- Wipa Suginta
- School of Biomolecular Science and Engineering (BSE), Vidyasirimedhi Institute of Science and Technology (VISTEC), Rayong, Thailand.
| | - Surapoj Sanram
- School of Biomolecular Science and Engineering (BSE), Vidyasirimedhi Institute of Science and Technology (VISTEC), Rayong, Thailand
| | - Anuwat Aunkham
- School of Biomolecular Science and Engineering (BSE), Vidyasirimedhi Institute of Science and Technology (VISTEC), Rayong, Thailand
| | - Mathias Winterhalter
- Department of Life Sciences and Chemistry, Jacobs University Bremen, Bremen, Germany
| | - Albert Schulte
- School of Biomolecular Science and Engineering (BSE), Vidyasirimedhi Institute of Science and Technology (VISTEC), Rayong, Thailand.
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13
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Okumura K, Maruyama Y, Takase R, Mikami B, Murata K, Hashimoto W. The role of calcium binding to the EF-hand-like motif in bacterial solute-binding protein for alginate import. Biosci Biotechnol Biochem 2021; 85:2410-2419. [PMID: 34610097 DOI: 10.1093/bbb/zbab170] [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: 07/31/2021] [Accepted: 09/23/2021] [Indexed: 11/14/2022]
Abstract
Gram-negative Sphingomonas sp. A1 incorporates acidic polysaccharide alginate into the cytoplasm via a cell-surface alginate-binding protein (AlgQ2)-dependent ATP-binding cassette transporter (AlgM1M2SS). We investigated the function of calcium bound to the EF-hand-like motif in AlgQ2 by introducing mutations at the calcium-binding site. The X-ray crystallography of the AlgQ2 mutant (D179A/E180A) demonstrated the absence of calcium binding and significant disorder of the EF-hand-like motif. Distinct from the wild-type AlgQ2, the mutant was quite unstable at temperature of strain A1 growth, although unsaturated alginate oligosaccharides stabilized the mutant by formation of substrate/protein complex. In the assay of ATPase and alginate transport by AlgM1M2SS reconstructed in the liposome, the wild-type and mutant AlgQ2 induced AlgM1M2SS ATPase activity in the presence of unsaturated alginate tetrasaccharide. These results indicate that the calcium bound to EF-hand-like motif stabilizes the substrate-unbound AlgQ2 but is not required for the complexation of substrate-bound AlgQ2 and AlgM1M2SS.
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Affiliation(s)
- Kenji Okumura
- Laboratory of Basic and Applied Molecular Biotechnology, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji, Kyoto, Japan
| | - Yukie Maruyama
- Laboratory of Food Microbiology, Department of Life Science, Faculty of Science and Engineering, Setsunan University, Neyagawa, Osaka, Japan
| | - Ryuichi Takase
- Laboratory of Basic and Applied Molecular Biotechnology, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji, Kyoto, Japan
| | - Bunzo Mikami
- Laboratory of Metabolic Sciences of Forest Plants and Microorganisms, Research Institute for Sustainable Humanosphere, Kyoto University, Uji, Kyoto, Japan
| | - Kousaku Murata
- Laboratory of Food Microbiology, Department of Life Science, Faculty of Science and Engineering, Setsunan University, Neyagawa, Osaka, Japan
| | - Wataru Hashimoto
- Laboratory of Basic and Applied Molecular Biotechnology, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji, Kyoto, Japan
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14
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Sharaf NG, Shahgholi M, Kim E, Lai JY, VanderVelde DG, Lee AT, Rees DC. Characterization of the ABC methionine transporter from Neisseria meningitidis reveals that lipidated MetQ is required for interaction. eLife 2021; 10:69742. [PMID: 34409939 PMCID: PMC8416018 DOI: 10.7554/elife.69742] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2021] [Accepted: 08/18/2021] [Indexed: 01/05/2023] Open
Abstract
NmMetQ is a substrate-binding protein (SBP) from Neisseria meningitidis that has been identified as a surface-exposed candidate antigen for meningococcal vaccines. However, this location for NmMetQ challenges the prevailing view that SBPs in Gram-negative bacteria are localized to the periplasmic space to promote interaction with their cognate ABC transporter embedded in the bacterial inner membrane. To elucidate the roles of NmMetQ, we characterized NmMetQ with and without its cognate ABC transporter (NmMetNI). Here, we show that NmMetQ is a lipoprotein (lipo-NmMetQ) that binds multiple methionine analogs and stimulates the ATPase activity of NmMetNI. Using single-particle electron cryo-microscopy, we determined the structures of NmMetNI in the presence and absence of lipo-NmMetQ. Based on our data, we propose that NmMetQ tethers to membranes via a lipid anchor and has dual function and localization, playing a role in NmMetNI-mediated transport at the inner membrane and moonlighting on the bacterial surface.
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Affiliation(s)
- Naima G Sharaf
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, United States.,Howard Hughes Medical Institute, California Institute of Technology, Pasadena, United States
| | - Mona Shahgholi
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, United States
| | - Esther Kim
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, United States
| | - Jeffrey Y Lai
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, United States.,Howard Hughes Medical Institute, California Institute of Technology, Pasadena, United States
| | - David G VanderVelde
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, United States
| | - Allen T Lee
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, United States.,Howard Hughes Medical Institute, California Institute of Technology, Pasadena, United States
| | - Douglas C Rees
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, United States.,Howard Hughes Medical Institute, California Institute of Technology, Pasadena, United States
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15
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Maisuls I, Singh J, Salto IP, Steiner ST, Kirse TM, Niemann S, Strassert CA, Faust A. Conjugated Pt(II) Complexes as Luminescence-Switch-On Reporters Addressing the Microenvironment of Bacterial Biofilms. Inorg Chem 2021; 60:11058-11069. [PMID: 34255500 DOI: 10.1021/acs.inorgchem.1c00860] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In this work, the synthesis, structural and photophysical characterization of six phosphorescent H2O-soluble Pt(II) complexes are reported while addressing their emission maxima, photoluminescence quantum yields (ΦL), lifetimes (τ), aggregation tendency, and microenvironment sensitivity as a function of the substitution pattern on the main tridentate luminophore. Different ancillary ligands, namely, a trisulfonated phosphane and maltohexaose-conjugated pyridines (with or without amide bridges), were introduced and evaluated for the realization of switch-on-photoluminescent labels reporting on the microenvironment sensed in biofilms of Gram+ and Gram- models, namely, Staphylococcus aureus and Escherichia coli. With the aid of confocal luminescence micro(spectro)scopy, we observed that selected complexes specifically interact with the biofilms while leaving planktonic cells unlabeled. By using photoluminescence lifetime imaging microscopy, excited-state lifetimes within S. aureus biofilms were measured. The photoluminescence intensities were drastically boosted, and the excited state lifetimes were significantly prolonged upon binding to the viscous biofilm matrix, mainly due to the suppression of radiationless deactivation pathways upon shielding from physical quenching processes, such as interactions with solvent molecules and 3O2. The best performances were attained for non-aggregating complexes with maltohexaose targeting units and without amide bridges. Notably, in the absence of the maltodextrin, a hydrophobic adamantyl moiety suffices to attain a sizeable labeling capacity. Moreover, photoluminescence studies showed that selected complexes can also effectively interact with E. coli biofilms, where the bacterial cells are able to partially uptake the maltodextrin-based agents. In summary, the herein introduced concepts enable the development of specific biofilm reporters providing spatial resolution as well as lifetime- and spectrum-based readouts. Considering that most theragnostic agents reported so far mainly address metabolically active bacteria at the surface of biofilms but without reaching cells deeply immersed in the matrix, a new platform with a clear structure-property correlation is provided for the early detection of such bacterial arrays.
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Affiliation(s)
- Iván Maisuls
- Institut für Anorganische und Analytische Chemie, CiMiC, SoN and CeNTech, Wesfälische Wilhelms-Universität Münster, Heisenbergstr. 11, 48149 Münster, Germany
| | - Jasveer Singh
- Institut für Anorganische und Analytische Chemie, CiMiC, SoN and CeNTech, Wesfälische Wilhelms-Universität Münster, Heisenbergstr. 11, 48149 Münster, Germany
| | - Ileana P Salto
- Institute of Medical Microbiology, University Hospital Münster, Domagkstr. 10, 48149 Münster, Germany
| | - Simon T Steiner
- European Institute for Molecular Imaging, University of Münster, Münster, Waldeyerstr. 15, 48159 Münster, Germany
| | - Thomas M Kirse
- Institut für Anorganische und Analytische Chemie, CiMiC, SoN and CeNTech, Wesfälische Wilhelms-Universität Münster, Heisenbergstr. 11, 48149 Münster, Germany
| | - Silke Niemann
- Institute of Medical Microbiology, University Hospital Münster, Domagkstr. 10, 48149 Münster, Germany.,Interdisciplinary Center of Clinical Research (IZKF), University Hospital Münster, 48149 Münster, Germany
| | - Cristian A Strassert
- Institut für Anorganische und Analytische Chemie, CiMiC, SoN and CeNTech, Wesfälische Wilhelms-Universität Münster, Heisenbergstr. 11, 48149 Münster, Germany
| | - Andreas Faust
- European Institute for Molecular Imaging, University of Münster, Münster, Waldeyerstr. 15, 48159 Münster, Germany.,Interdisciplinary Center of Clinical Research (IZKF), University Hospital Münster, 48149 Münster, Germany
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16
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Abreu B, Cruz C, Oliveira ASF, Soares CM. ATP hydrolysis and nucleotide exit enhance maltose translocation in the MalFGK 2E importer. Sci Rep 2021; 11:10591. [PMID: 34012037 PMCID: PMC8134467 DOI: 10.1038/s41598-021-89556-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 04/27/2021] [Indexed: 02/03/2023] Open
Abstract
ATP binding cassette (ABC) transporters employ ATP hydrolysis to harness substrate translocation across membranes. The Escherichia coli MalFGK2E maltose importer is an example of a type I ABC importer and a model system for this class of ABC transporters. The MalFGK2E importer is responsible for the intake of malto-oligossacharides in E.coli. Despite being extensively studied, little is known about the effect of ATP hydrolysis and nucleotide exit on substrate transport. In this work, we studied this phenomenon using extensive molecular dynamics simulations (MD) along with potential of mean force calculations of maltose transport across the pore, in the pre-hydrolysis, post-hydrolysis and nucleotide-free states. We concluded that ATP hydrolysis and nucleotide exit trigger conformational changes that result in the decrease of energetic barriers to maltose translocation towards the cytoplasm, with a concomitant increase of the energy barrier in the periplasmic side of the pore, contributing for the irreversibility of the process. We also identified key residues that aid in positioning and orientation of maltose, as well as a novel binding pocket for maltose in MalG. Additionally, ATP hydrolysis leads to conformations similar to the nucleotide-free state. This study shows the contribution of ATP hydrolysis and nucleotide exit in the transport cycle, shedding light on ABC type I importer mechanisms.
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Affiliation(s)
- Bárbara Abreu
- grid.10772.330000000121511713ITQB NOVA, Instituto de Tecnologia Química E Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Carlos Cruz
- grid.10772.330000000121511713ITQB NOVA, Instituto de Tecnologia Química E Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - A. Sofia F. Oliveira
- grid.10772.330000000121511713ITQB NOVA, Instituto de Tecnologia Química E Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal ,grid.5337.20000 0004 1936 7603School of Biochemistry and Centre for Computational Chemistry, University of Bristol, Bristol, UK
| | - Cláudio M. Soares
- grid.10772.330000000121511713ITQB NOVA, Instituto de Tecnologia Química E Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
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17
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Cryo-EM structure of ABCG5/G8 in complex with modulating antibodies. Commun Biol 2021; 4:526. [PMID: 33953337 PMCID: PMC8100176 DOI: 10.1038/s42003-021-02039-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Accepted: 03/25/2021] [Indexed: 12/20/2022] Open
Abstract
The heterodimer of ATP-binding cassette transporter ABCG5 and ABCG8 mediates the excretion of sterols from liver and intestine, playing a critical role in cholesterol homeostasis. Here, we present the cryo-EM structure of ABCG5/G8 in complex with the Fab fragments from two monoclonal antibodies at 3.3Å resolution. The high-resolution structure reveals a unique dimer interface between the nucleotide-binding domains (NBD) of opposing transporters, consisting of an ordered network of salt bridges between the conserved NPXDFXXD motif and serving as a pivot point that may be important for the transport cycle. While mAb 11F4 increases the ATPase activity potentially by stabilization of the NBD dimer formation, mAb 2E10 inhibits ATP hydrolysis, likely by restricting the relative movement between the RecA and helical domain of ABCG8 NBD. Our study not only provides insights into the structural elements important for the transport cycle but also reveals novel epitopes for potential therapeutic interventions.
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18
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Li F, Egea PF, Vecchio AJ, Asial I, Gupta M, Paulino J, Bajaj R, Dickinson MS, Ferguson-Miller S, Monk BC, Stroud RM. Highlighting membrane protein structure and function: A celebration of the Protein Data Bank. J Biol Chem 2021; 296:100557. [PMID: 33744283 PMCID: PMC8102919 DOI: 10.1016/j.jbc.2021.100557] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Revised: 02/10/2021] [Accepted: 03/16/2021] [Indexed: 12/13/2022] Open
Abstract
Biological membranes define the boundaries of cells and compartmentalize the chemical and physical processes required for life. Many biological processes are carried out by proteins embedded in or associated with such membranes. Determination of membrane protein (MP) structures at atomic or near-atomic resolution plays a vital role in elucidating their structural and functional impact in biology. This endeavor has determined 1198 unique MP structures as of early 2021. The value of these structures is expanded greatly by deposition of their three-dimensional (3D) coordinates into the Protein Data Bank (PDB) after the first atomic MP structure was elucidated in 1985. Since then, free access to MP structures facilitates broader and deeper understanding of MPs, which provides crucial new insights into their biological functions. Here we highlight the structural and functional biology of representative MPs and landmarks in the evolution of new technologies, with insights into key developments influenced by the PDB in magnifying their impact.
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Affiliation(s)
- Fei Li
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, California, USA; Department of Neurology, University of California San Francisco, San Francisco, California, USA
| | - Pascal F Egea
- Department of Biological Chemistry, School of Medicine, University of California Los Angeles, Los Angeles, California, USA
| | - Alex J Vecchio
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, Nebraska, USA
| | | | - Meghna Gupta
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, California, USA
| | - Joana Paulino
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, California, USA
| | - Ruchika Bajaj
- Department of Bioengineering and Therapeutic Sciences, University of California San Francisco, San Francisco, California, USA
| | - Miles Sasha Dickinson
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, California, USA
| | - Shelagh Ferguson-Miller
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan, USA
| | - Brian C Monk
- Sir John Walsh Research Institute and Department of Oral Sciences, University of Otago, North Dunedin, Dunedin, New Zealand
| | - Robert M Stroud
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, California, USA.
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19
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Axer A, Jumde RP, Adam S, Faust A, Schäfers M, Fobker M, Koehnke J, Hirsch AKH, Gilmour R. Enhancing glycan stability via site-selective fluorination: modulating substrate orientation by molecular design. Chem Sci 2020; 12:1286-1294. [PMID: 34163891 PMCID: PMC8179167 DOI: 10.1039/d0sc04297h] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Single site OH → F substitution at the termini of maltotetraose leads to significantly improved hydrolytic stability towards α-amylase and α-glucosidase relative to the natural compound. To explore the effect of molecular editing, selectively modified oligosaccharides were prepared via a convergent α-selective strategy. Incubation experiments in purified α-amylase and α-glucosidase, and in human and murine blood serum, provide insight into the influence of fluorine on the hydrolytic stability of these clinically important scaffolds. Enhancements of ca. 1 order of magnitude result from these subtle single point mutations. Modification at the monosaccharide furthest from the probable enzymatic cleavage termini leads to the greatest improvement in stability. In the case of α-amylase, docking studies revealed that retentive C2-fluorination at the reducing end inverts the orientation in which the substrate is bound. A co-crystal structure of human α-amylase revealed maltose units bound at the active-site. In view of the evolving popularity of C(sp3)–F bioisosteres in medicinal chemistry, and the importance of maltodextrins in bacterial imaging, this discovery begins to reconcile the information-rich nature of carbohydrates with their intrinsic hydrolytic vulnerabilities. Single site OH → F substitution at the termini of maltotetraose leads to significantly improved hydrolytic stability towards α-amylase and α-glucosidase relative to the natural compound.![]()
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Affiliation(s)
- Alexander Axer
- Organisch Chemisches Institut, WWU Münster Corrensstraße 36 48149 Münster Germany
| | - Ravindra P Jumde
- Department of Drug Discovery and Optimization, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Centre for Infection Research (HZI) University Campus E8.1 66123 Saarbrücken Germany
| | - Sebastian Adam
- Workgroup Structural Biology of Biosynthetic Enzymes, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Institute for Infection Research (HZI) University Campus E8.1 66123 Saarbrücken Germany
| | - Andreas Faust
- European Institute for Molecular Imaging Münster Germany
| | - Michael Schäfers
- European Institute for Molecular Imaging Münster Germany.,Department of Nuclear Medicine, University Hospital (UKM) Münster Germany
| | - Manfred Fobker
- Center for Laboratory Medicine, WWU Münster Münster Germany
| | - Jesko Koehnke
- Workgroup Structural Biology of Biosynthetic Enzymes, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Institute for Infection Research (HZI) University Campus E8.1 66123 Saarbrücken Germany.,Department of Pharmacy, Saarland University 66123 Saarbrücken Germany
| | - Anna K H Hirsch
- Department of Drug Discovery and Optimization, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Centre for Infection Research (HZI) University Campus E8.1 66123 Saarbrücken Germany.,Department of Pharmacy, Saarland University 66123 Saarbrücken Germany
| | - Ryan Gilmour
- Organisch Chemisches Institut, WWU Münster Corrensstraße 36 48149 Münster Germany
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20
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Kohno M, Arakawa T, Sunagawa N, Mori T, Igarashi K, Nishimoto T, Fushinobu S. Molecular analysis of cyclic α-maltosyl-(1→6)-maltose binding protein in the bacterial metabolic pathway. PLoS One 2020; 15:e0241912. [PMID: 33211750 PMCID: PMC7676653 DOI: 10.1371/journal.pone.0241912] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 10/22/2020] [Indexed: 11/18/2022] Open
Abstract
Cyclic α-maltosyl-(1→6)-maltose (CMM) is a cyclic glucotetrasaccharide with alternating α-1,4 and α-1,6 linkages. Here, we report functional and structural analyses on CMM-binding protein (CMMBP), which is a substrate-binding protein (SBP) of an ABC importer system of the bacteria Arthrobacter globiformis. Isothermal titration calorimetry analysis revealed that CMMBP specifically bound to CMM with a Kd value of 9.6 nM. The crystal structure of CMMBP was determined at a resolution of 1.47 Å, and a panose molecule was bound in a cleft between two domains. To delineate its structural features, the crystal structure of CMMBP was compared with other SBPs specific for carbohydrates, such as cyclic α-nigerosyl-(1→6)-nigerose and cyclodextrins. These results indicate that A. globiformis has a unique metabolic pathway specialized for CMM.
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Affiliation(s)
- Masaki Kohno
- Department of Biotechnology, The University of Tokyo, Tokyo, Japan
- R&D Division, HAYASHIBARA CO., LTD., Okayama, Japan
| | - Takatoshi Arakawa
- Department of Biotechnology, The University of Tokyo, Tokyo, Japan
- Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, Tokyo, Japan
| | - Naoki Sunagawa
- Department of Biomaterial Sciences, The University of Tokyo, Tokyo, Japan
| | - Tetsuya Mori
- R&D Division, HAYASHIBARA CO., LTD., Okayama, Japan
| | - Kiyohiko Igarashi
- Department of Biomaterial Sciences, The University of Tokyo, Tokyo, Japan
- VTT Technical Research Centre of Finland Ltd., Espoo, Finland
| | | | - Shinya Fushinobu
- Department of Biotechnology, The University of Tokyo, Tokyo, Japan
- Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, Tokyo, Japan
- * E-mail:
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21
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Mahmoudi Gomari M, Saraygord-Afshari N, Farsimadan M, Rostami N, Aghamiri S, Farajollahi MM. Opportunities and challenges of the tag-assisted protein purification techniques: Applications in the pharmaceutical industry. Biotechnol Adv 2020; 45:107653. [PMID: 33157154 DOI: 10.1016/j.biotechadv.2020.107653] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Revised: 10/22/2020] [Accepted: 10/29/2020] [Indexed: 01/16/2023]
Abstract
Tag-assisted protein purification is a method of choice for both academic researches and large-scale industrial demands. Application of the purification tags in the protein production process can help to save time and cost, but the design and application of tagged fusion proteins are challenging. An appropriate tagging strategy must provide sufficient expression yield and high purity for the final protein products while preserving their native structure and function. Thanks to the recent advances in the bioinformatics and emergence of high-throughput techniques (e.g. SEREX), many new tags are introduced to the market. A variety of interfering and non-interfering tags have currently broadened their application scope beyond the traditional use as a simple purification tool. They can take part in many biochemical and analytical features and act as solubility and protein expression enhancers, probe tracker for online visualization, detectors of post-translational modifications, and carrier-driven tags. Given the variability and growing number of the purification tags, here we reviewed the protein- and peptide-structured purification tags used in the affinity, ion-exchange, reverse phase, and immobilized metal ion affinity chromatographies. We highlighted the demand for purification tags in the pharmaceutical industry and discussed the impact of self-cleavable tags, aggregating tags, and nanotechnology on both the column-based and column-free purification techniques.
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Affiliation(s)
- Mohammad Mahmoudi Gomari
- Department of Medical Biotechnology, Faculty of Allied Medical Sciences, Iran University of Medical Sciences, Tehran, Iran
| | - Neda Saraygord-Afshari
- Department of Medical Biotechnology, Faculty of Allied Medical Sciences, Iran University of Medical Sciences, Tehran, Iran.
| | - Marziye Farsimadan
- Department of Biology, Faculty of Sciences, University of Guilan, Rasht, Iran
| | - Neda Rostami
- Department of Chemical Engineering, Faculty of Engineering, Arak University, Iran
| | - Shahin Aghamiri
- Student research committee, Department of medical biotechnology, School of Advanced Technologies in Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mohammad M Farajollahi
- Department of Medical Biotechnology, Faculty of Allied Medical Sciences, Iran University of Medical Sciences, Tehran, Iran
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22
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de Boer M, Cordes T, Poolman B. Kinetic Modelling of Transport Inhibition by Substrates in ABC Importers. J Mol Biol 2020; 432:5565-5576. [PMID: 32800784 DOI: 10.1016/j.jmb.2020.08.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 08/05/2020] [Accepted: 08/09/2020] [Indexed: 12/11/2022]
Abstract
Prokaryotic ATP-binding cassette (ABC) importers require a substrate-binding protein (SBP) for the capture and delivery of the cognate substrate to the transmembrane domain (TMD) of the transporter. Various biochemical compounds have been identified that bind to the SBP but are not transported. The mechanistic basis for the "non-cognate" substrates not being transported differs. Some non-cognate substrates fail to trigger the appropriate conformational change in the SBP, resulting in loss of affinity for the TMD or the inability to allosterically activate transport. In another mechanism, the SBP cannot release the bound non-cognate substrate. Here, we used rate equations to derive the steady-state transport rate of cognate substrates of an ABC importer and investigated how non-cognate substrates influence this rate. We found that under limiting non-cognate substrate concentrations, the transport rate remains unaltered for each of the mechanisms. In contrast, at saturating substrate and SBP concentrations, the effect of the non-cognate substrate depends heavily on the respective mechanism. For instance, the transport rate becomes zero when the non-cognate substrate cannot be released by the SBP. Yet it remains unaffected when substrate release is possible but the SBP cannot dock onto the TMDs. Our work shows how the different mechanisms of substrate inhibition impact the transport kinetics, which is relevant for understanding and manipulating solute fluxes and hence the propagation of cells in nutritionally complex milieus.
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Affiliation(s)
- Marijn de Boer
- Molecular Microscopy Research Group, Zernike Institute for Advanced Materials, University of Groningen, Groningen, the Netherlands; Department of Biochemistry, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, the Netherlands.
| | - Thorben Cordes
- Molecular Microscopy Research Group, Zernike Institute for Advanced Materials, University of Groningen, Groningen, the Netherlands; Physical and Synthetic Biology, Faculty of Biology, Ludwig-Maximilians-Universität München, Großhadernerstr, 2-4, 82152 Planegg-Martinsried, Germany
| | - Bert Poolman
- Department of Biochemistry, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, the Netherlands.
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23
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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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24
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Zlitni A, Gowrishankar G, Steinberg I, Haywood T, Sam Gambhir S. Maltotriose-based probes for fluorescence and photoacoustic imaging of bacterial infections. Nat Commun 2020; 11:1250. [PMID: 32144257 PMCID: PMC7060353 DOI: 10.1038/s41467-020-14985-8] [Citation(s) in RCA: 66] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Accepted: 02/13/2020] [Indexed: 11/09/2022] Open
Abstract
Currently, there are no non-invasive tools to accurately diagnose wound and surgical site infections before they become systemic or cause significant anatomical damage. Fluorescence and photoacoustic imaging are cost-effective imaging modalities that can be used to noninvasively diagnose bacterial infections when paired with a molecularly targeted infection imaging agent. Here, we develop a fluorescent derivative of maltotriose (Cy7-1-maltotriose), which is shown to be taken up in a variety of gram-positive and gram-negative bacterial strains in vitro. In vivo fluorescence and photoacoustic imaging studies highlight the ability of this probe to detect infection, assess infection burden, and visualize the effectiveness of antibiotic treatment in E. coli-induced myositis and a clinically relevant S. aureus wound infection murine model. In addition, we show that maltotriose is an ideal scaffold for infection imaging agents encompassing better pharmacokinetic properties and in vivo stability than other maltodextrins (e.g. maltohexose).
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Affiliation(s)
- Aimen Zlitni
- Molecular Imaging Program at Stanford, Stanford University, Stanford, CA, 94305, USA
- Department of Radiology, Stanford University, Stanford, CA, 94305, USA
| | - Gayatri Gowrishankar
- Molecular Imaging Program at Stanford, Stanford University, Stanford, CA, 94305, USA
- Department of Radiology, Stanford University, Stanford, CA, 94305, USA
| | - Idan Steinberg
- Molecular Imaging Program at Stanford, Stanford University, Stanford, CA, 94305, USA
- Department of Radiology, Stanford University, Stanford, CA, 94305, USA
| | - Tom Haywood
- Molecular Imaging Program at Stanford, Stanford University, Stanford, CA, 94305, USA
- Department of Radiology, Stanford University, Stanford, CA, 94305, USA
| | - Sanjiv Sam Gambhir
- Molecular Imaging Program at Stanford, Stanford University, Stanford, CA, 94305, USA.
- Department of Radiology, Stanford University, Stanford, CA, 94305, USA.
- Department of Bioengineering, Department of Materials Science & Engineering, Stanford University, Stanford, CA, 94305, USA.
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25
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Chen W, Dilsizian V. Molecular Imaging of Cardiovascular Device Infection: Targeting the Bacteria or the Host–Pathogen Immune Response? J Nucl Med 2020; 61:319-326. [DOI: 10.2967/jnumed.119.228304] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Accepted: 01/22/2020] [Indexed: 12/14/2022] Open
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26
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Mächtel R, Narducci A, Griffith DA, Cordes T, Orelle C. An integrated transport mechanism of the maltose ABC importer. Res Microbiol 2019; 170:321-337. [PMID: 31560984 PMCID: PMC6906923 DOI: 10.1016/j.resmic.2019.09.004] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2019] [Revised: 09/10/2019] [Accepted: 09/13/2019] [Indexed: 12/27/2022]
Abstract
ATP-binding cassette (ABC) transporters use the energy of ATP hydrolysis to transport a large diversity of molecules actively across biological membranes. A combination of biochemical, biophysical, and structural studies has established the maltose transporter MalFGK2 as one of the best characterized proteins of the ABC family. MalF and MalG are the transmembrane domains, and two MalKs form a homodimer of nucleotide-binding domains. A periplasmic maltose-binding protein (MalE) delivers maltose and other maltodextrins to the transporter, and triggers its ATPase activity. Substrate import occurs in a unidirectional manner by ATP-driven conformational changes in MalK2 that allow alternating access of the substrate-binding site in MalF to each side of the membrane. In this review, we present an integrated molecular mechanism of the transport process considering all currently available information. Furthermore, we summarize remaining inconsistencies and outline possible future routes to decipher the full mechanistic details of transport by MalEFGK2 complex and that of related importer systems.
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Affiliation(s)
- Rebecca Mächtel
- Physical and Synthetic Biology, Faculty of Biology, Ludwig-Maximilians-Universität München, Großhadernerstr. 2-4, 82152 Planegg-Martinsried, Germany
| | - Alessandra Narducci
- Physical and Synthetic Biology, Faculty of Biology, Ludwig-Maximilians-Universität München, Großhadernerstr. 2-4, 82152 Planegg-Martinsried, Germany
| | - Douglas A Griffith
- Physical and Synthetic Biology, Faculty of Biology, Ludwig-Maximilians-Universität München, Großhadernerstr. 2-4, 82152 Planegg-Martinsried, Germany
| | - Thorben Cordes
- Physical and Synthetic Biology, Faculty of Biology, Ludwig-Maximilians-Universität München, Großhadernerstr. 2-4, 82152 Planegg-Martinsried, Germany.
| | - Cédric Orelle
- Université de Lyon, CNRS, UMR5086 "Molecular Microbiology and Structural Biochemistry", IBCP, 7 passage du Vercors, 69367 Lyon, France.
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27
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Cao L, Wang J, Sun L, Kong Z, Wu Q, Wang Z. Transcriptional analysis reveals the relativity of acid tolerance and antimicrobial peptide resistance of Salmonella. Microb Pathog 2019; 136:103701. [PMID: 31472260 DOI: 10.1016/j.micpath.2019.103701] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 08/27/2019] [Accepted: 08/28/2019] [Indexed: 01/20/2023]
Abstract
The objective of this study was to comprehensively identify the target genes induced by acid stimulation in Salmonella, and to clarify the relativity of acid tolerance and antimicrobial peptide resistance. A clinical S. Typhimurium strain, S6, was selected and performed a transcriptome analysis under the acid tolerance response. In total, we found 1461 genes to be differentially expressed, including 721 up-regulated and 740 down-regulated genes. Functional annotation revealed differentially expressed genes to be associated with regulation, metabolism, transport, virulence, and motility. Interestingly, KEGG pathway analysis demonstrated that the induced genes by acid were enriched in cationic antimicrobial peptide resistance, sulfur relay system, ABC transporters, and two-component system pathway. Therein, PhoQ belonging to the two-component system PhoP-PhoQ that promotes virulence by detecting the macrophage phagosome and controls the transcript levels of many genes associated with the resistance to AMPs; MarA, a multiple antibiotic resistance factor; SapA, one of the encoding gene of sapABCDF operon that confers resistance to small cationic peptides of Salmonella; YejB, one of the encoding gene of yejABEF operon that confers resistance to antimicrobial peptides and contributes to the virulence of Salmonella, were all induced by acid stimulation, and could potentially explain that there is a correlation between acid tolerance and AMPs resistance, and finally affects the virulence of intracellular pathogenic bacteria.
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Affiliation(s)
- Li Cao
- Beijing Key Laboratory of Traditional Chinese Veterinary Medicine, Animal Science and Technology College, Beijing University of Agriculture, Beijing, 102206, China
| | - Jiawei Wang
- Beijing Key Laboratory of Traditional Chinese Veterinary Medicine, Animal Science and Technology College, Beijing University of Agriculture, Beijing, 102206, China
| | - Lu Sun
- Beijing Key Laboratory of Traditional Chinese Veterinary Medicine, Animal Science and Technology College, Beijing University of Agriculture, Beijing, 102206, China
| | - Zian Kong
- Beijing Key Laboratory of Traditional Chinese Veterinary Medicine, Animal Science and Technology College, Beijing University of Agriculture, Beijing, 102206, China
| | - Qingmin Wu
- Key Laboratory of Animal Epidemiology and Zoonosis of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China
| | - Zhen Wang
- Beijing Key Laboratory of Traditional Chinese Veterinary Medicine, Animal Science and Technology College, Beijing University of Agriculture, Beijing, 102206, China.
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28
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Enkavi G, Javanainen M, Kulig W, Róg T, Vattulainen I. Multiscale Simulations of Biological Membranes: The Challenge To Understand Biological Phenomena in a Living Substance. Chem Rev 2019; 119:5607-5774. [PMID: 30859819 PMCID: PMC6727218 DOI: 10.1021/acs.chemrev.8b00538] [Citation(s) in RCA: 175] [Impact Index Per Article: 35.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Indexed: 12/23/2022]
Abstract
Biological membranes are tricky to investigate. They are complex in terms of molecular composition and structure, functional over a wide range of time scales, and characterized by nonequilibrium conditions. Because of all of these features, simulations are a great technique to study biomembrane behavior. A significant part of the functional processes in biological membranes takes place at the molecular level; thus computer simulations are the method of choice to explore how their properties emerge from specific molecular features and how the interplay among the numerous molecules gives rise to function over spatial and time scales larger than the molecular ones. In this review, we focus on this broad theme. We discuss the current state-of-the-art of biomembrane simulations that, until now, have largely focused on a rather narrow picture of the complexity of the membranes. Given this, we also discuss the challenges that we should unravel in the foreseeable future. Numerous features such as the actin-cytoskeleton network, the glycocalyx network, and nonequilibrium transport under ATP-driven conditions have so far received very little attention; however, the potential of simulations to solve them would be exceptionally high. A major milestone for this research would be that one day we could say that computer simulations genuinely research biological membranes, not just lipid bilayers.
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Affiliation(s)
- Giray Enkavi
- Department
of Physics, University of
Helsinki, P.O. Box 64, FI-00014 Helsinki, Finland
| | - Matti Javanainen
- Department
of Physics, University of
Helsinki, P.O. Box 64, FI-00014 Helsinki, Finland
- Institute
of Organic Chemistry and Biochemistry of the Czech Academy
of Sciences, Flemingovo naḿesti 542/2, 16610 Prague, Czech Republic
- Computational
Physics Laboratory, Tampere University, P.O. Box 692, FI-33014 Tampere, Finland
| | - Waldemar Kulig
- Department
of Physics, University of
Helsinki, P.O. Box 64, FI-00014 Helsinki, Finland
| | - Tomasz Róg
- Department
of Physics, University of
Helsinki, P.O. Box 64, FI-00014 Helsinki, Finland
- Computational
Physics Laboratory, Tampere University, P.O. Box 692, FI-33014 Tampere, Finland
| | - Ilpo Vattulainen
- Department
of Physics, University of
Helsinki, P.O. Box 64, FI-00014 Helsinki, Finland
- Computational
Physics Laboratory, Tampere University, P.O. Box 692, FI-33014 Tampere, Finland
- MEMPHYS-Center
for Biomembrane Physics
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29
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de Boer M, Gouridis G, Vietrov R, Begg SL, Schuurman-Wolters GK, Husada F, Eleftheriadis N, Poolman B, McDevitt CA, Cordes T. Conformational and dynamic plasticity in substrate-binding proteins underlies selective transport in ABC importers. eLife 2019; 8:44652. [PMID: 30900991 PMCID: PMC6450668 DOI: 10.7554/elife.44652] [Citation(s) in RCA: 72] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 03/22/2019] [Indexed: 12/20/2022] Open
Abstract
Substrate-binding proteins (SBPs) are associated with ATP-binding cassette importers and switch from an open to a closed conformation upon substrate binding, providing specificity for transport. We investigated the effect of substrates on the conformational dynamics of six SBPs and the impact on transport. Using single-molecule FRET, we reveal an unrecognized diversity of plasticity in SBPs. We show that a unique closed SBP conformation does not exist for transported substrates. Instead, SBPs sample a range of conformations that activate transport. Certain non-transported ligands leave the structure largely unaltered or trigger a conformation distinct from that of transported substrates. Intriguingly, in some cases, similar SBP conformations are formed by both transported and non-transported ligands. In this case, the inability for transport arises from slow opening of the SBP or the selectivity provided by the translocator. Our results reveal the complex interplay between ligand-SBP interactions, SBP conformational dynamics and substrate transport.
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Affiliation(s)
- Marijn de Boer
- Molecular Microscopy Research Group, Zernike Institute for Advanced Materials, University of Groningen, Groningen, The Netherlands
| | - Giorgos Gouridis
- Molecular Microscopy Research Group, Zernike Institute for Advanced Materials, University of Groningen, Groningen, The Netherlands.,Physical and Synthetic Biology, Faculty of Biology, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany.,Laboratory of Molecular Bacteriology, Department of Microbiology and Immunology, Rega Institute for Medical Research, KU Leuven, Leuven, Belgium
| | - Ruslan Vietrov
- Department of Biochemistry, Groningen Biomolecular Science and Biotechnology Institute, University of Groningen, Groningen, The Netherlands.,Zernike Institute for Advanced Materials, University of Groningen, Groningen, The Netherlands
| | - Stephanie L Begg
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Australia
| | - Gea K Schuurman-Wolters
- Department of Biochemistry, Groningen Biomolecular Science and Biotechnology Institute, University of Groningen, Groningen, The Netherlands.,Zernike Institute for Advanced Materials, University of Groningen, Groningen, The Netherlands
| | - Florence Husada
- Molecular Microscopy Research Group, Zernike Institute for Advanced Materials, University of Groningen, Groningen, The Netherlands
| | - Nikolaos Eleftheriadis
- Molecular Microscopy Research Group, Zernike Institute for Advanced Materials, University of Groningen, Groningen, The Netherlands
| | - Bert Poolman
- Department of Biochemistry, Groningen Biomolecular Science and Biotechnology Institute, University of Groningen, Groningen, The Netherlands.,Zernike Institute for Advanced Materials, University of Groningen, Groningen, The Netherlands
| | - Christopher A McDevitt
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Australia.,Research Centre for Infectious Diseases, School of Biological Sciences, The University of Adelaide, Adelaide, Australia
| | - Thorben Cordes
- Molecular Microscopy Research Group, Zernike Institute for Advanced Materials, University of Groningen, Groningen, The Netherlands.,Physical and Synthetic Biology, Faculty of Biology, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany
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30
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Kamischke C, Fan J, Bergeron J, Kulasekara HD, Dalebroux ZD, Burrell A, Kollman JM, Miller SI. The Acinetobacter baumannii Mla system and glycerophospholipid transport to the outer membrane. eLife 2019; 8:e40171. [PMID: 30638443 PMCID: PMC6365058 DOI: 10.7554/elife.40171] [Citation(s) in RCA: 68] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Accepted: 01/11/2019] [Indexed: 01/14/2023] Open
Abstract
The outer membrane (OM) of Gram-negative bacteria serves as a selective permeability barrier that allows entry of essential nutrients while excluding toxic compounds, including antibiotics. The OM is asymmetric and contains an outer leaflet of lipopolysaccharides (LPS) or lipooligosaccharides (LOS) and an inner leaflet of glycerophospholipids (GPL). We screened Acinetobacter baumannii transposon mutants and identified a number of mutants with OM defects, including an ABC transporter system homologous to the Mla system in E. coli. We further show that this opportunistic, antibiotic-resistant pathogen uses this multicomponent protein complex and ATP hydrolysis at the inner membrane to promote GPL export to the OM. The broad conservation of the Mla system in Gram-negative bacteria suggests the system may play a conserved role in OM biogenesis. The importance of the Mla system to Acinetobacter baumannii OM integrity and antibiotic sensitivity suggests that its components may serve as new antimicrobial therapeutic targets.
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Affiliation(s)
- Cassandra Kamischke
- Department of Microbiology, University of Washington, Seattle, United States
| | - Junping Fan
- Department of Microbiology, University of Washington, Seattle, United States
| | - Julien Bergeron
- Department of Biochemistry, University of Washington, Seattle, United States
- Department of Molecular Biology and Biotechnology, The University of Sheffield, Sheffield, United Kingdom
| | | | - Zachary D Dalebroux
- Department of Microbiology, University of Washington, Seattle, United States
| | - Anika Burrell
- Department of Biochemistry, University of Washington, Seattle, United States
| | - Justin M Kollman
- Department of Biochemistry, University of Washington, Seattle, United States
| | - Samuel I Miller
- Department of Microbiology, University of Washington, Seattle, United States
- Department of Genome Sciences, University of Washington, Seattle, United States
- Department of Medicine, University of Washington, Seattle, United States
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31
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Evidence from Mutational Analysis for a Single Transmembrane Substrate Binding Site in the Histidine ATP-Binding Cassette Transporter of Salmonella enterica Serovar Typhimurium. J Bacteriol 2018; 201:JB.00521-18. [PMID: 30348830 DOI: 10.1128/jb.00521-18] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Accepted: 10/14/2018] [Indexed: 11/20/2022] Open
Abstract
The histidine ATP-binding cassette (ABC) transporter of Salmonella enterica serovar Typhimurium is among the best-studied type I ABC import systems. The transporter consists of two transmembrane subunits, HisQ and HisM, and a homodimer of the nucleotide-binding subunit, HisP. Substrates are delivered by two periplasmic solute binding proteins, HisJ and LAO, with preferences for histidine and for lysine, arginine, and ornithine, respectively. A homology model was built by using the arginine-bound crystal structure of the closely related Art(QN)2 transporter of Thermoanaerobacter tengcongensis as the template. In the homodimeric Art(QN)2, one substrate molecule is bound to each of the ArtQ subunits, whereas the structural model and sequence alignments predict only one substrate molecule in contact with HisM. To address the question whether one or two binding sites exist in heterodimeric HisQM, we have studied the functional consequences of mutations by monitoring (i) the complementation of growth on d-histidine of auxotrophic tester strains, (ii) the growth of tester strains on arginine as a nitrogen source, and (iii) ATPase activity of purified variants in a lipid environment. Our results demonstrate that two negatively charged residues, namely, HisM-E166 and HisQ-D61, are indispensable for function. Furthermore, the complete reconstruction of an ArtQ-like binding site in HisQ resulted in an inactive transporter. Likewise, switching the positions of both negatively charged residues between HisQ and HisM caused transport-deficient phenotypes. Thus, we propose that one substrate molecule is primarily liganded by residues of HisM while HisQ-D61 forms a crucial salt bridge with the α-amino group of the substrate.IMPORTANCE Canonical ATP-binding cassette (ABC) importers are major players in the translocation of numerous nutrients, vitamins, and growth factors to the cytoplasm of prokaryotes. Moreover, some ABC importers have been identified as virulence factors in bacterial pathogenesis. Thus, a full understanding of their mode of action is considered a prerequisite, among others, for the development of novel antibacterial drugs. However, mainly owing to the lack of structural information, the knowledge of the chemical nature and number of substrate binding sites formed by the transmembrane subunits of ABC importers is scarce. Here, we provide evidence from mutational analyses that, in contrast to homologous homodimeric systems, the heterodimeric histidine transporter of Salmonella enterica serovar Typhimurium is liganding only one substrate molecule between its transmembrane subunits, HisM and HisQ.
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Noncanonical role for the binding protein in substrate uptake by the MetNI methionine ATP Binding Cassette (ABC) transporter. Proc Natl Acad Sci U S A 2018; 115:E10596-E10604. [PMID: 30352853 PMCID: PMC6233128 DOI: 10.1073/pnas.1811003115] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
The high-affinity methionine importer MetNI belongs to the ATP Binding Cassette (ABC) family of transporters that carry out the ATP-dependent uptake of substrates into cells. As with other ABC importers, MetNI requires a soluble binding protein (MetQ) that in the canonical mechanistic model delivers substrates to the transporter. We made the unexpected observation that a MetQ variant with significantly impaired ligand-binding properties supports d-selenomethionine uptake at a higher rate than wild-type MetQ. A crystal structure of MetNIQ in the outward-facing conformation reveals access channels through the binding protein to the transmembrane translocation pathway. These studies support a noncanonical role for the binding protein in facilitating the uptake of certain substrates directly through the transporter–binding protein complex. The Escherichia coli methionine ABC transporter MetNI exhibits both high-affinity transport toward l-methionine and broad specificity toward methionine derivatives, including d-methionine. In this work, we characterize the transport of d-methionine derivatives by the MetNI transporter. Unexpectedly, the N229A substrate-binding deficient variant of the cognate binding protein MetQ was found to support high MetNI transport activity toward d-selenomethionine. We determined the crystal structure at 2.95 Å resolution of the ATPγS-bound MetNIQ complex in the outward-facing conformation with the N229A apo MetQ variant. This structure revealed conformational changes in MetQ providing substrate access through the binding protein to the transmembrane translocation pathway. MetQ likely mediates uptake of methionine derivatives through two mechanisms: in the methionine-bound form delivering substrate from the periplasm to the transporter (the canonical mechanism) and in the apo form by facilitating ligand binding when complexed to the transporter (the noncanonical mechanism). This dual role for substrate-binding proteins is proposed to provide a kinetic strategy for ABC transporters to transport both high- and low-affinity substrates present in a physiological concentration range.
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33
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One Intact Transmembrane Substrate Binding Site Is Sufficient for the Function of the Homodimeric Type I ATP-Binding Cassette Importer for Positively Charged Amino Acids Art(MP) 2 of Geobacillus stearothermophilus. J Bacteriol 2018; 200:JB.00092-18. [PMID: 29581409 DOI: 10.1128/jb.00092-18] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Accepted: 03/20/2018] [Indexed: 02/04/2023] Open
Abstract
ATP-binding cassette (ABC) transport systems comprise two transmembrane domains/subunits that form a translocation path and two nucleotide-binding domains/subunits that bind and hydrolyze ATP. Prokaryotic canonical ABC import systems require an extracellular substrate-binding protein for function. Knowledge of substrate-binding sites within the transmembrane subunits is scarce. Recent crystal structures of the ABC importer Art(QN)2 for positively charged amino acids of Thermoanerobacter tengcongensis revealed the presence of one substrate molecule in a defined binding pocket in each of the transmembrane subunits, ArtQ (J. Yu, J. Ge, J. Heuveling, E. Schneider, and M. Yang, Proc Natl Acad Sci U S A 112:5243-5248, 2015, https://doi.org/10.1073/pnas.1415037112). This finding raised the question of whether both sites must be loaded with substrate prior to initiation of the transport cycle. To address this matter, we first explored the role of key residues that form the binding pocket in the closely related Art(MP)2 transporter of Geobacillus stearothermophilus, by monitoring consequences of mutations in ArtM on ATPase and transport activity at the level of purified proteins embedded in liposomes. Our results emphasize that two negatively charged residues (E153 and D160) are crucial for wild-type function. Furthermore, the variant Art[M(L67D)P]2 exhibited strongly impaired activities, which is why it was considered for construction of a hybrid complex containing one intact and one impaired substrate-binding site. Activity assays clearly revealed that one intact binding site was sufficient for function. To our knowledge, our study provides the first biochemical evidence on transmembrane substrate-binding sites of an ABC importer.IMPORTANCE Canonical prokaryotic ATP-binding cassette importers mediate the uptake of a large variety of chemicals, including nutrients, osmoprotectants, growth factors, and trace elements. Some also play a role in bacterial pathogenesis, which is why full understanding of their mode of action is of the utmost importance. One of the unsolved problems refers to the chemical nature and number of substrate binding sites formed by the transmembrane subunits. Here, we report that a hybrid amino acid transporter of G. stearothermophilus, encompassing one intact and one impaired transmembrane binding site, is fully competent in transport, suggesting that the binding of one substrate molecule is sufficient to trigger the translocation process.
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34
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Antibiotic Hybrids: the Next Generation of Agents and Adjuvants against Gram-Negative Pathogens? Clin Microbiol Rev 2018. [PMID: 29540434 DOI: 10.1128/cmr.00077-17] [Citation(s) in RCA: 176] [Impact Index Per Article: 29.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The global incidence of drug-resistant Gram-negative bacillary infections has been increasing, and there is a dire need to develop novel strategies to overcome this problem. Intrinsic resistance in Gram-negative bacteria, such as their protective outer membrane and constitutively overexpressed efflux pumps, is a major survival weapon that renders them refractory to current antibiotics. Several potential avenues to overcome this problem have been at the heart of antibiotic drug discovery in the past few decades. We review some of these strategies, with emphasis on antibiotic hybrids either as stand-alone antibacterial agents or as adjuvants that potentiate a primary antibiotic in Gram-negative bacteria. Antibiotic hybrid is defined in this review as a synthetic construct of two or more pharmacophores belonging to an established agent known to elicit a desired antimicrobial effect. The concepts, advances, and challenges of antibiotic hybrids are elaborated in this article. Moreover, we discuss several antibiotic hybrids that were or are in clinical evaluation. Mechanistic insights into how tobramycin-based antibiotic hybrids are able to potentiate legacy antibiotics in multidrug-resistant Gram-negative bacilli are also highlighted. Antibiotic hybrids indeed have a promising future as a therapeutic strategy to overcome drug resistance in Gram-negative pathogens and/or expand the usefulness of our current antibiotic arsenal.
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Axer A, Hermann S, Kehr G, Clases D, Karst U, Fischer-Riepe L, Roth J, Fobker M, Schäfers M, Gilmour R, Faust A. Harnessing the Maltodextrin Transport Mechanism for Targeted Bacterial Imaging: Structural Requirements for Improved in vivo Stability in Tracer Design. ChemMedChem 2018; 13:241-250. [DOI: 10.1002/cmdc.201700543] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Revised: 11/09/2017] [Indexed: 01/01/2023]
Affiliation(s)
- Alexander Axer
- Institute for Organic Chemistry; WWU Münster; Corrensstrasse 40 48149 Münster Germany
- DFG EXC 1003 Cluster of Excellence “Cells in Motion”; WWU Münster; Münster Germany
| | - Sven Hermann
- European Institute for Molecular Imaging; WWU Münster; Waldeyerstrasse 15 48149 Münster Germany
- Interdisciplinary Center of Clinical Research (IZKF); University Hospital Münster; 48149 Münster Germany
- DFG EXC 1003 Cluster of Excellence “Cells in Motion”; WWU Münster; Münster Germany
| | - Gerald Kehr
- Institute for Organic Chemistry; WWU Münster; Corrensstrasse 40 48149 Münster Germany
| | - David Clases
- Institute for Inorganic and Analytical Chemistry; WWU Münster; Corrensstrasse 30 48149 Münster Germany
| | - Uwe Karst
- Institute for Inorganic and Analytical Chemistry; WWU Münster; Corrensstrasse 30 48149 Münster Germany
- DFG EXC 1003 Cluster of Excellence “Cells in Motion”; WWU Münster; Münster Germany
| | - Lena Fischer-Riepe
- Institute for Immunology; WWU Münster; Röntgenstrasse 21 48149 Münster Germany
| | - Johannes Roth
- Institute for Immunology; WWU Münster; Röntgenstrasse 21 48149 Münster Germany
- Interdisciplinary Center of Clinical Research (IZKF); University Hospital Münster; 48149 Münster Germany
- DFG EXC 1003 Cluster of Excellence “Cells in Motion”; WWU Münster; Münster Germany
| | - Manfred Fobker
- Center of Laboratory Medicine; WWU Münster; Albert Schweitzer Campus 1 48149 Münster Germany
| | - Michael Schäfers
- European Institute for Molecular Imaging; WWU Münster; Waldeyerstrasse 15 48149 Münster Germany
- Interdisciplinary Center of Clinical Research (IZKF); University Hospital Münster; 48149 Münster Germany
- Department of Nuclear Medicine; University Hospital Münster; Albert Schweitzer Campus 1 48149 Münster Germany
- DFG EXC 1003 Cluster of Excellence “Cells in Motion”; WWU Münster; Münster Germany
| | - Ryan Gilmour
- Institute for Organic Chemistry; WWU Münster; Corrensstrasse 40 48149 Münster Germany
- DFG EXC 1003 Cluster of Excellence “Cells in Motion”; WWU Münster; Münster Germany
| | - Andreas Faust
- European Institute for Molecular Imaging; WWU Münster; Waldeyerstrasse 15 48149 Münster Germany
- Interdisciplinary Center of Clinical Research (IZKF); University Hospital Münster; 48149 Münster Germany
- DFG EXC 1003 Cluster of Excellence “Cells in Motion”; WWU Münster; Münster Germany
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Jia K, Wang G, Liang L, Wang M, Wang H, Xu X. Preliminary Transcriptome Analysis of Mature Biofilm and Planktonic Cells of Salmonella Enteritidis Exposure to Acid Stress. Front Microbiol 2017; 8:1861. [PMID: 29018430 PMCID: PMC5622974 DOI: 10.3389/fmicb.2017.01861] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Accepted: 09/12/2017] [Indexed: 11/13/2022] Open
Abstract
Salmonella has emerged as a well-recognized food-borne pathogen, with many strains able to form biofilms and thus cause cross-contamination in food processing environments where acid-based disinfectants are widely encountered. In the present study, RNA sequencing was employed to establish complete transcriptome profiles of Salmonella Enteritidis in the forms of planktonic and biofilm-associated cells cultured in Tryptic Soytone Broth (TSB) and acidic TSB (aTSB). The gene expression patterns of S. Enteritidis significantly differed between biofilm-associated and planktonic cells cultivated under the same conditions. The assembled transcriptome of S. Enteritidis in this study contained 5,442 assembled transcripts, including 3,877 differentially expressed genes (DEGs) identified in biofilm and planktonic cells. These DEGs were enriched in terms such as regulation of biological process, metabolic process, macromolecular complex, binding and transferase activity, which may play crucial roles in the biofilm formation of S. Enteritidis cultivated in aTSB. Three significant pathways were observed to be enriched under acidic conditions: bacterial chemotaxis, porphyrin-chlorophyll metabolism and sulfur metabolism. In addition, 15 differentially expressed novel non-coding small RNAs (sRNAs) were identified, and only one was found to be up-regulated in mature biofilms. This preliminary study of the S. Enteritidis transcriptome serves as a basis for future investigations examining the complex network systems that regulate Salmonella biofilm in acidic environments, which provide information on biofilm formation and acid stress interaction that may facilitate the development of novel disinfection procedures in the food processing industry.
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Affiliation(s)
- Kun Jia
- National Center of Meat Quality and Safety Control, Nanjing Agricultural University, Nanjing, China
| | - Guangyu Wang
- Jiangsu Collaborative Innovation Center of Meat Production and Processing, Quality and Safety Control, Nanjing Agricultural University, Nanjing, China
| | - Lijiao Liang
- National Center of Meat Quality and Safety Control, Nanjing Agricultural University, Nanjing, China
| | - Meng Wang
- National Center of Meat Quality and Safety Control, Nanjing Agricultural University, Nanjing, China
| | - Huhu Wang
- National Center of Meat Quality and Safety Control, Nanjing Agricultural University, Nanjing, China
| | - Xinglian Xu
- Jiangsu Collaborative Innovation Center of Meat Production and Processing, Quality and Safety Control, Nanjing Agricultural University, Nanjing, China
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Kaneko A, Uenishi K, Maruyama Y, Mizuno N, Baba S, Kumasaka T, Mikami B, Murata K, Hashimoto W. A solute-binding protein in the closed conformation induces ATP hydrolysis in a bacterial ATP-binding cassette transporter involved in the import of alginate. J Biol Chem 2017; 292:15681-15690. [PMID: 28768763 DOI: 10.1074/jbc.m117.793992] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2017] [Revised: 07/12/2017] [Indexed: 01/31/2023] Open
Abstract
The Gram-negative bacterium Sphingomonas sp. A1 incorporates alginate into cells via the cell-surface pit without prior depolymerization by extracellular enzymes. Alginate import across cytoplasmic membranes thereby depends on the ATP-binding cassette transporter AlgM1M2SS (a heterotetramer of AlgM1, AlgM2, and AlgS), which cooperates with the periplasmic solute-binding protein AlgQ1 or AlgQ2; however, several details of AlgM1M2SS-mediated alginate import are not well-understood. Herein, we analyzed ATPase and transport activities of AlgM1M2SS after reconstitution into liposomes with AlgQ2 and alginate oligosaccharide substrates having different polymerization degrees (PDs). Longer alginate oligosaccharides (PD ≥ 5) stimulated the ATPase activity of AlgM1M2SS but were inert as substrates of AlgM1M2SS-mediated transport, indicating that AlgM1M2SS-mediated ATP hydrolysis can be stimulated independently of substrate transport. Using X-ray crystallography in the presence of AlgQ2 and long alginate oligosaccharides (PD 6-8) and with the humid air and glue-coating method, we determined the crystal structure of AlgM1M2SS in complex with oligosaccharide-bound AlgQ2 at 3.6 Å resolution. The structure of the ATP-binding cassette transporter in complex with non-transport ligand-bound periplasmic solute-binding protein revealed that AlgM1M2SS and AlgQ2 adopt inward-facing and closed conformations, respectively. These in vitro assays and structural analyses indicated that interactions between AlgM1M2SS in the inward-facing conformation and periplasmic ligand-bound AlgQ2 in the closed conformation induce ATP hydrolysis by the ATP-binding protein AlgS. We conclude that substrate-bound AlgQ2 in the closed conformation initially interacts with AlgM1M2SS, the AlgM1M2SS-AlgQ2 complex then forms, and this formation is followed by ATP hydrolysis.
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Affiliation(s)
- Ai Kaneko
- From the Laboratory of Basic and Applied Molecular Biotechnology, Division of Food Science and Biotechnology, and
| | - Kasumi Uenishi
- From the Laboratory of Basic and Applied Molecular Biotechnology, Division of Food Science and Biotechnology, and
| | - Yukie Maruyama
- the Laboratory of Food Microbiology, Department of Life Science, Faculty of Science and Engineering, Setsunan University, Neyagawa, Osaka 572-8508, Japan, and
| | - Nobuhiro Mizuno
- the Japan Synchrotron Radiation Research Institute (JASRI), Sayo-gun, Hyogo 679-5198, Japan
| | - Seiki Baba
- the Japan Synchrotron Radiation Research Institute (JASRI), Sayo-gun, Hyogo 679-5198, Japan
| | - Takashi Kumasaka
- the Japan Synchrotron Radiation Research Institute (JASRI), Sayo-gun, Hyogo 679-5198, Japan
| | - Bunzo Mikami
- the Laboratory of Applied Structural Biology, Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Kousaku Murata
- the Laboratory of Food Microbiology, Department of Life Science, Faculty of Science and Engineering, Setsunan University, Neyagawa, Osaka 572-8508, Japan, and
| | - Wataru Hashimoto
- From the Laboratory of Basic and Applied Molecular Biotechnology, Division of Food Science and Biotechnology, and
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Homburg C, Bommer M, Wuttge S, Hobe C, Beck S, Dobbek H, Deutscher J, Licht A, Schneider E. Inducer exclusion in Firmicutes: insights into the regulation of a carbohydrate ATP binding cassette transporter from Lactobacillus casei BL23 by the signal transducing protein P-Ser46-HPr. Mol Microbiol 2017; 105:25-45. [PMID: 28370477 DOI: 10.1111/mmi.13680] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/26/2017] [Indexed: 12/24/2022]
Abstract
Catabolite repression is a mechanism that enables bacteria to control carbon utilization. As part of this global regulatory network, components of the phosphoenolpyruvate:carbohydrate phosphotransferase system inhibit the uptake of less favorable sugars when a preferred carbon source such as glucose is available. This process is termed inducer exclusion. In bacteria belonging to the phylum Firmicutes, HPr, phosphorylated at serine 46 (P-Ser46-HPr) is the key player but its mode of action is elusive. To address this question at the level of purified protein components, we have chosen a homolog of the Escherichia coli maltose/maltodextrin ATP-binding cassette transporter from Lactobacillus casei (MalE1-MalF1G1K12 ) as a model system. We show that the solute binding protein, MalE1, binds linear and cyclic maltodextrins but not maltose. Crystal structures of MalE1 complexed with these sugars provide a clue why maltose is not a substrate. P-Ser46-HPr inhibited MalE1/maltotetraose-stimulated ATPase activity of the transporter incorporated in proteoliposomes. Furthermore, cross-linking experiments revealed that P-Ser46-HPr contacts the nucleotide-binding subunit, MalK1, in proximity to the Walker A motif. However, P-Ser46-HPr did not block binding of ATP to MalK1. Together, our findings provide first biochemical evidence that P-Ser-HPr arrests the transport cycle by preventing ATP hydrolysis at the MalK1 subunits of the transporter.
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Affiliation(s)
- Constanze Homburg
- Institut für Biologie/Physiologie der Mikroorganismen, Humboldt-Universität zu Berlin, Berlin, D-10099, Germany
| | - Martin Bommer
- Institut für Biologie/Strukturbiologie und Biochemie, Humboldt-Universität zu Berlin, Berlin, D-10099, Germany
| | - Steven Wuttge
- Institut für Biologie/Physiologie der Mikroorganismen, Humboldt-Universität zu Berlin, Berlin, D-10099, Germany
| | - Carolin Hobe
- Institut für Biologie/Physiologie der Mikroorganismen, Humboldt-Universität zu Berlin, Berlin, D-10099, Germany
| | - Sebastian Beck
- Institut für Chemie/Angewandte Analytik und Umweltchemie, Humboldt-Universität zu Berlin, Berlin, D-10099, Germany
| | - Holger Dobbek
- Institut für Biologie/Strukturbiologie und Biochemie, Humboldt-Universität zu Berlin, Berlin, D-10099, Germany
| | - Josef Deutscher
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, F-78350, France.,Expression Génétique Microbienne, Institut de Biologie Physico-Chimique, Centre National de la Recherche Scientifique, UMR8261, Paris, F-75005, France
| | - Anke Licht
- Institut für Biologie/Physiologie der Mikroorganismen, Humboldt-Universität zu Berlin, Berlin, D-10099, Germany
| | - Erwin Schneider
- Institut für Biologie/Physiologie der Mikroorganismen, Humboldt-Universität zu Berlin, Berlin, D-10099, Germany
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Teichmann L, Chen C, Hoffmann T, Smits SHJ, Schmitt L, Bremer E. From substrate specificity to promiscuity: hybrid ABC transporters for osmoprotectants. Mol Microbiol 2017; 104:761-780. [PMID: 28256787 DOI: 10.1111/mmi.13660] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Revised: 02/25/2017] [Accepted: 02/27/2017] [Indexed: 01/03/2023]
Abstract
The ABC-transporters OpuB and OpuC from Bacillus subtilis function as osmoprotectant import systems. Their structural genes have most likely evolved through a duplication event but the two transporters are remarkably different in their substrate profile. OpuB possesses narrow substrate specificity, while OpuC is promiscuous. We assessed the functionality of hybrids between these two ABC-transporters by reciprocally exchanging the coding regions for the OpuBC and OpuCC substrate-binding proteins between the corresponding opuB and opuC operons. Substantiating the critical role of the binding protein in setting the substrate specificity of ABC transporters, OpuB::OpuCC turned into a promiscuous system, while OpuC::OpuBC now exhibited narrow substrate specificity. Both hybrid transporters possessed a high affinity for their substrates but the transport capacity of the OpuB::OpuCC system was moderate due to the synthesis of only low amounts of the xenogenetic OpuCC protein. Suppressor mutations causing single amino acid substitutions in the GbsR repressor controlling the choline to glycine betaine biosynthesis pathway greatly improved OpuB::OpuCC-mediated compatible solute import through transcriptional up-regulation of the hybrid opuB::opuCC operon. Collectively, we demonstrate for the first time that one can synthetically switch the substrate specificity of a given ABC transporter by combining its core components with a xenogenetic ligand-binding protein.
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Affiliation(s)
- Laura Teichmann
- Laboratory for Molecular Microbiology, Department of Biology, Philipps-University Marburg, Karl-von-Frisch Str. 8, Marburg, D-35043, Germany
| | - Chiliang Chen
- Laboratory for Molecular Microbiology, Department of Biology, Philipps-University Marburg, Karl-von-Frisch Str. 8, Marburg, D-35043, Germany.,LOEWE-Center for Synthetic Microbiology, Philipps-University Marburg, Hans-Meerweinstr. 6, Marburg, D-35043, Germany
| | - Tamara Hoffmann
- Laboratory for Molecular Microbiology, Department of Biology, Philipps-University Marburg, Karl-von-Frisch Str. 8, Marburg, D-35043, Germany
| | - Sander H J Smits
- Institute of Biochemistry, Heinrich-Heine-University Düsseldorf, Universitätsstr. 1, Düsseldorf D-40225, Germany
| | - Lutz Schmitt
- Institute of Biochemistry, Heinrich-Heine-University Düsseldorf, Universitätsstr. 1, Düsseldorf D-40225, Germany
| | - Erhard Bremer
- Laboratory for Molecular Microbiology, Department of Biology, Philipps-University Marburg, Karl-von-Frisch Str. 8, Marburg, D-35043, Germany.,LOEWE-Center for Synthetic Microbiology, Philipps-University Marburg, Hans-Meerweinstr. 6, Marburg, D-35043, Germany
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40
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Fabre L, Bao H, Innes J, Duong F, Rouiller I. Negative Stain Single-particle EM of the Maltose Transporter in Nanodiscs Reveals Asymmetric Closure of MalK 2 and Catalytic Roles of ATP, MalE, and Maltose. J Biol Chem 2017; 292:5457-5464. [PMID: 28188291 DOI: 10.1074/jbc.m116.757898] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Revised: 02/08/2017] [Indexed: 12/26/2022] Open
Abstract
The Escherichia coli MalE-MalFGK2 complex is one of the best characterized members of the large and ubiquitous family of ATP-binding cassette (ABC) transporters. It is composed of a membrane-spanning heterodimer, MalF-MalG; a homodimeric ATPase, MalK2; and a periplasmic maltose receptor, MalE. Opening and closure of MalK2 is coupled to conformational changes in MalF-MalG and the alternate exposition of the substrate-binding site to either side of the membrane. To further define this alternate access mechanism and the impact of ATP, MalE, and maltose on the conformation of the transporter during the transport cycle, we have reconstituted MalFGK2 in nanodiscs and analyzed its conformations under 10 different biochemical conditions using negative stain single-particle EM. EM map results (at 15-25 Å resolution) indicate that binding of ATP to MalK2 promotes an asymmetric, semi-closed conformation in accordance with the low ATPase activity of MalFGK2 In the presence of MalE, the MalK dimer becomes fully closed, gaining the ability to hydrolyze ATP. In the presence of ADP or maltose, MalE·MalFGK2 remains essentially in a semi-closed symmetric conformation, indicating that release of these ligands is required for the return to the initial state. Taken together, this structural information provides a rationale for the stimulation of MalK ATPase activity by MalE as well as by maltose.
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Affiliation(s)
- Lucien Fabre
- From the Department of Anatomy and Cell Biology, Groupe de Recherche Axé sur la Structure des Protéines, Groupe d'Étude des Protéines Membranaires, McGill University, Montreal, Quebec H3A 2B2, Canada and
| | - Huan Bao
- the Department of Biochemistry and Molecular Biology, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - James Innes
- From the Department of Anatomy and Cell Biology, Groupe de Recherche Axé sur la Structure des Protéines, Groupe d'Étude des Protéines Membranaires, McGill University, Montreal, Quebec H3A 2B2, Canada and
| | - Franck Duong
- the Department of Biochemistry and Molecular Biology, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Isabelle Rouiller
- From the Department of Anatomy and Cell Biology, Groupe de Recherche Axé sur la Structure des Protéines, Groupe d'Étude des Protéines Membranaires, McGill University, Montreal, Quebec H3A 2B2, Canada and
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41
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Hopfner KP. Invited review: Architectures and mechanisms of ATP binding cassette proteins. Biopolymers 2017; 105:492-504. [PMID: 27037766 DOI: 10.1002/bip.22843] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Revised: 03/24/2016] [Accepted: 03/28/2016] [Indexed: 12/29/2022]
Abstract
ATP binding cassette (ABC) ATPases form chemo-mechanical engines and switches that function in a broad range of biological processes. Most prominently, a very large family of integral membrane NTPases-ABC transporters-catalyzes the import or export of a diverse molecules across membranes. ABC proteins are also important components of the chromosome segregation, recombination, and DNA repair machineries and regulate or catalyze critical steps of ribosomal protein synthesis. Recent structural and mechanistic studies draw interesting architectural and mechanistic parallels between diverse ABC proteins. Here, I review this state of our understanding how NTP-dependent conformational changes of ABC proteins drive diverse biological processes. © 2016 Wiley Periodicals, Inc. Biopolymers 105: 492-504, 2016.
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Affiliation(s)
- Karl-Peter Hopfner
- Department Biochemistry, Ludwig-Maximilians-Universität München, Feodor-Lynen-Str. 25, 81377 Munich, Germany.,Gene Center, Ludwig-Maximilians-Universität München, Feodor-Lynen-Str. 25, 81377 Munich, Germany.,Center for Integrated Protein Science Munich, Ludwigs-Maximilians-Universität München, Feodor-Lynen-Str. 25, 81377 Munich, Germany
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42
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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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43
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Weng J, Gu S, Gao X, Huang X, Wang W. Maltose-binding protein effectively stabilizes the partially closed conformation of the ATP-binding cassette transporter MalFGK2. Phys Chem Chem Phys 2017; 19:9366-9373. [DOI: 10.1039/c6cp07943a] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Maltose transporter MalFGK2is a type-I importer in the ATP-binding cassette (ABC) transporter superfamily.
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Affiliation(s)
- Jingwei Weng
- Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials
- Department of Chemistry, and Institutes of Biomedical Sciences
- Fudan University
- Shanghai
- P. R. China
| | - Shuo Gu
- Department of Chemistry
- Institute for Advance Study and School of Science
- The Hong Kong University of Science and Technology
- Kowloon
- China
| | - Xin Gao
- Computer, Electrical and Mathematical Sciences and Engineering Division
- King Abdullah University of Science and Technology
- Thuwal
- Saudi Arabia
| | - Xuhui Huang
- Department of Chemistry
- Institute for Advance Study and School of Science
- The Hong Kong University of Science and Technology
- Kowloon
- China
| | - Wenning Wang
- Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials
- Department of Chemistry, and Institutes of Biomedical Sciences
- Fudan University
- Shanghai
- P. R. China
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44
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Pan C, Weng J, Wang W. Conformational Dynamics and Protein-Substrate Interaction of ABC Transporter BtuCD at the Occluded State Revealed by Molecular Dynamics Simulations. Biochemistry 2016; 55:6897-6907. [PMID: 27951660 DOI: 10.1021/acs.biochem.6b00386] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
ATP-binding cassette (ABC) transporters are ubiquitous in all three kingdoms of life and are implicated in many clinically relevant physiological processes. They couple the energy released by ATP hydrolysis to facilitate substrate translocation across cell membranes. The crystal structures of type II ABC importers have revealed their unique transmembrane domain architecture consisting of 10 transmembrane helices and their structurally conserved nucleotide-binding domains among all ABC transporters. However, molecular details of the interactions between the importers and their substrate remain largely elusive. Taking vitamin B12 importer BtuCD as an exemplar of type II importers, we investigated the dynamics of its occluded state and the detailed protein-substrate interactions using molecular dynamics simulation. Our trajectories show that the importer accommodates the substrate through a nonspecific binding mode as the substrate undergoes evident vertical and tilt motions inside the translocation cavity. Extensive hydrogen bond and hydrophobic interactions were observed between the substrate and the importer; however, most of these interactions are weak, with <38% occurrence. The presence of substrate leads to enlargement of the translocation cavity, especially at its cytoplasmic end, which may activate cytoplasmic regions and probably facilitate the transportation. The perturbations caused by periplasmic binding protein and nucleotides were also investigated. The study provides deeper insight into the translocation mechanism of BtuCD.
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Affiliation(s)
- Chao Pan
- Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Department of Chemistry, and Institutes of Biomedical Sciences, Fudan University , Shanghai, P. R. China
| | - Jingwei Weng
- Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Department of Chemistry, and Institutes of Biomedical Sciences, Fudan University , Shanghai, P. R. China
| | - Wenning Wang
- Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Department of Chemistry, and Institutes of Biomedical Sciences, Fudan University , Shanghai, P. R. China
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45
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Lv X, Liu H, Chen H, Gong H. Coupling between ATP hydrolysis and protein conformational change in maltose transporter. Proteins 2016; 85:207-220. [PMID: 27616441 DOI: 10.1002/prot.25160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Revised: 08/29/2016] [Accepted: 09/02/2016] [Indexed: 11/12/2022]
Abstract
As the intracellular part of maltose transporter, MalK dimer utilizes the energy of ATP hydrolysis to drive protein conformational change, which then facilitates substrate transport. Free energy evaluation of the complete conformational change before and after ATP hydrolysis is helpful to elucidate the mechanism of chemical-to-mechanical energy conversion in MalK dimer, but is lacking in previous studies. In this work, we used molecular dynamics simulations to investigate the structural transition of MalK dimer among closed, semi-open and open states. We observed spontaneous structural transition from closed to open state in the ADP-bound system and partial closure of MalK dimer from the semi-open state in the ATP-bound system. Subsequently, we calculated the reaction pathways connecting the closed and open states for the ATP- and ADP-bound systems and evaluated the free energy profiles along the paths. Our results suggested that the closed state is stable in the presence of ATP but is markedly destabilized when ATP is hydrolyzed to ADP, which thus explains the coupling between ATP hydrolysis and protein conformational change of MalK dimer in thermodynamics. Proteins 2017; 85:207-220. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Xiaoying Lv
- MOE Key Laboratory of Bioinformatics, School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Hao Liu
- Department of Bioinformatics and Biostatistics, State Key Laboratory of Microbial metabolism, College of Life Sciences and Biotechnology, Shanghai Jiaotong University, Shanghai, 200240, China
| | - Haifeng Chen
- Department of Bioinformatics and Biostatistics, State Key Laboratory of Microbial metabolism, College of Life Sciences and Biotechnology, Shanghai Jiaotong University, Shanghai, 200240, China
| | - Haipeng Gong
- MOE Key Laboratory of Bioinformatics, School of Life Sciences, Tsinghua University, Beijing, 100084, China
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46
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Lv D, Li C, Tan J, Zhang X, Wang C, Su J. Identification of functionally key residues in maltose transporter with an elastic network model-based thermodynamic method. Mol Phys 2016. [DOI: 10.1080/00268976.2016.1234077] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- Dashuai Lv
- College of Life Science and Bioengineering, Beijing University of Technology, Beijing, China
| | - Chunhua Li
- College of Life Science and Bioengineering, Beijing University of Technology, Beijing, China
| | - Jianjun Tan
- College of Life Science and Bioengineering, Beijing University of Technology, Beijing, China
| | - Xiaoyi Zhang
- College of Life Science and Bioengineering, Beijing University of Technology, Beijing, China
| | - Cunxin Wang
- College of Life Science and Bioengineering, Beijing University of Technology, Beijing, China
| | - Jiguo Su
- College of Science, Yanshan University, Qinhuangdao, China
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47
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Ejby M, Fredslund F, Andersen JM, Vujičić Žagar A, Henriksen JR, Andersen TL, Svensson B, Slotboom DJ, Abou Hachem M. An ATP Binding Cassette Transporter Mediates the Uptake of α-(1,6)-Linked Dietary Oligosaccharides in Bifidobacterium and Correlates with Competitive Growth on These Substrates. J Biol Chem 2016; 291:20220-31. [PMID: 27502277 DOI: 10.1074/jbc.m116.746529] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2016] [Indexed: 11/06/2022] Open
Abstract
The molecular details and impact of oligosaccharide uptake by distinct human gut microbiota (HGM) are currently not well understood. Non-digestible dietary galacto- and gluco-α-(1,6)-oligosaccharides from legumes and starch, respectively, are preferentially fermented by mainly bifidobacteria and lactobacilli in the human gut. Here we show that the solute binding protein (BlG16BP) associated with an ATP binding cassette (ABC) transporter from the probiotic Bifidobacterium animalis subsp. lactis Bl-04 binds α-(1,6)-linked glucosides and galactosides of varying size, linkage, and monosaccharide composition with preference for the trisaccharides raffinose and panose. This preference is also reflected in the α-(1,6)-galactoside uptake profile of the bacterium. Structures of BlG16BP in complex with raffinose and panose revealed the basis for the remarkable ligand binding plasticity of BlG16BP, which recognizes the non-reducing α-(1,6)-diglycoside in its ligands. BlG16BP homologues occur predominantly in bifidobacteria and a few Firmicutes but lack in other HGMs. Among seven bifidobacterial taxa, only those possessing this transporter displayed growth on α-(1,6)-glycosides. Competition assays revealed that the dominant HGM commensal Bacteroides ovatus was out-competed by B. animalis subsp. lactis Bl-04 in mixed cultures growing on raffinose, the preferred ligand for the BlG16BP. By comparison, B. ovatus mono-cultures grew very efficiently on this trisaccharide. These findings suggest that the ABC-mediated uptake of raffinose provides an important competitive advantage, particularly against dominant Bacteroides that lack glycan-specific ABC-transporters. This novel insight highlights the role of glycan transport in defining the metabolic specialization of gut bacteria.
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Affiliation(s)
- Morten Ejby
- From the Protein Glycoscience and Biotechnology, Department of Bioengineering, Elektrovej, Building 375
| | - Folmer Fredslund
- MaxLab, MAX IV Laboratory, Lund University, Ole Römers väg 1, 221 00 LUND, Sweden, and
| | - Joakim Mark Andersen
- From the Protein Glycoscience and Biotechnology, Department of Bioengineering, Elektrovej, Building 375
| | - Andreja Vujičić Žagar
- Membrane Enzymology, Institute for Biomolecular Sciences and Biotechnology, Rijksuniversiteit Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | | | - Thomas Lars Andersen
- Department of Microtechnology and Nanotechnology, Produktionstorvet Building 423, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
| | - Birte Svensson
- From the Protein Glycoscience and Biotechnology, Department of Bioengineering, Elektrovej, Building 375
| | - Dirk Jan Slotboom
- Membrane Enzymology, Institute for Biomolecular Sciences and Biotechnology, Rijksuniversiteit Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Maher Abou Hachem
- From the Protein Glycoscience and Biotechnology, Department of Bioengineering, Elektrovej, Building 375,
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48
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Choi JH, Xiong T, Ostermeier M. The interplay between effector binding and allostery in an engineered protein switch. Protein Sci 2016; 25:1605-16. [PMID: 27272021 DOI: 10.1002/pro.2962] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Revised: 06/02/2016] [Accepted: 06/03/2016] [Indexed: 01/05/2023]
Abstract
The protein design rules for engineering allosteric regulation are not well understood. A fundamental understanding of the determinants of ligand binding in an allosteric context could facilitate the design and construction of versatile protein switches and biosensors. Here, we conducted extensive in vitro and in vivo characterization of the effects of 285 unique point mutations at 15 residues in the maltose-binding pocket of the maltose-activated β-lactamase MBP317-347. MBP317-347 is an allosteric enzyme formed by the insertion of TEM-1 β-lactamase into the E. coli maltose binding protein (MBP). We find that the maltose-dependent resistance to ampicillin conferred to the cells by the MBP317-347 switch gene (the switch phenotype) is very robust to mutations, with most mutations slightly improving the switch phenotype. We identified 15 mutations that improved switch performance from twofold to 22-fold, primarily by decreasing the catalytic activity in the absence of maltose, perhaps by disrupting interactions that cause a small fraction of MBP in solution to exist in a partially closed state in the absence of maltose. Other notable mutations include K15D and K15H that increased maltose affinity 30-fold and Y155K and Y155R that compromised switching by diminishing the ability of maltose to increase catalytic activity. The data also provided insights into normal MBP physiology, as select mutations at D14, W62, and F156 retained high maltose affinity but abolished the switch's ability to substitute for MBP in the transport of maltose into the cell. The results reveal the complex relationship between ligand binding and allostery in this engineered switch.
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Affiliation(s)
- Jay H Choi
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, 3400 N. Charles St, Baltimore, Maryland, 21218
| | - Tina Xiong
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, 3400 N. Charles St, Baltimore, Maryland, 21218
| | - Marc Ostermeier
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, 3400 N. Charles St, Baltimore, Maryland, 21218
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49
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Galstyan A, Block D, Niemann S, Grüner MC, Abbruzzetti S, Oneto M, Daniliuc CG, Hermann S, Viappiani C, Schäfers M, Löffler B, Strassert CA, Faust A. Labeling and Selective Inactivation of Gram-Positive Bacteria Employing Bimodal Photoprobes with Dual Readouts. Chemistry 2016; 22:5243-52. [PMID: 26929124 DOI: 10.1002/chem.201504935] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Indexed: 01/17/2023]
Abstract
Carbohydrate-conjugated silicon(IV) phthalocyanines with bimodal photoactivity were developed as probes with both fluorescent labeling and photosensitizing capabilities, and the concomitant fluorescent labeling and photoinduced inactivation of Gram-positive and Gram-negative models was explored. The maltohexaose-conjugated photoprobe provides a dual readout to distinguish between both groups of pathogens, as only the Gram-positive species was inactivated, even though both appeared labeled with near-infrared luminescence. Antibiotic resistance did not hinder the phototoxic effect, as even the methicillin-resistant pathogen Staphylococcus aureus (MRSA) was completely photoinactivated. Time-resolved confocal fluorescence microscopy analysis suggests that the photoprobe sticks onto the outer rim of the microorganisms, explaining the resistance of Gram-negative species on the basis of their membrane constitution. The mannose-conjugated photoprobe yields a different readout because it is able to label and to inactivate only the Gram-positive strain.
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Affiliation(s)
- Anzhela Galstyan
- European Institute for Molecular Imaging, Waldeyerstr. 15, 48149, Münster, Germany. .,Physikalisches Institut and Center for Nanotechnology (CeNTech), Westfälische Wilhelms-Universität Münster, Heisenbergstr. 11, 48149, Münster, Germany.
| | - Desiree Block
- Institut für Medizinische Mikrobiologie, Universitätsklinikum Münster, Domagkstr. 10, 48149, Münster, Germany
| | - Silke Niemann
- Institut für Medizinische Mikrobiologie, Universitätsklinikum Münster, Domagkstr. 10, 48149, Münster, Germany
| | - Malte C Grüner
- Physikalisches Institut and Center for Nanotechnology (CeNTech), Westfälische Wilhelms-Universität Münster, Heisenbergstr. 11, 48149, Münster, Germany
| | - Stefania Abbruzzetti
- Dip. di Bioscienze Università degli Studi di Parma, NEST, Istituto Nanoscienze CNR, viale delle Scienze 11A, 43124, Parma, Italia
| | - Michele Oneto
- Fondazione Istituto Italiano di Tecnologia, Via Morego, 30, 16163, Genova, Italy
| | - Constantin G Daniliuc
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstr. 40, 48149, Münster, Germany
| | - Sven Hermann
- European Institute for Molecular Imaging, Waldeyerstr. 15, 48149, Münster, Germany
| | - Cristiano Viappiani
- Dip. di Fisica e Scienze della Terra, Università degli Studi di Parma, NEST, Istituto Nanoscienze CNR, viale delle Scienze 7A, 43124, Parma, Italia
| | - Michael Schäfers
- European Institute for Molecular Imaging, Waldeyerstr. 15, 48149, Münster, Germany.,Klinik für Nuklearmedizin, Universitätsklinikum Münster, Albert Schweitzer-Campus 1, 48149, Münster, Germany
| | - Bettina Löffler
- Institut für Medizinische Mikrobiologie, Universitätsklinikum Jena, Erlanger Allee 101, 07747, Jena, Germany
| | - Cristian A Strassert
- Physikalisches Institut and Center for Nanotechnology (CeNTech), Westfälische Wilhelms-Universität Münster, Heisenbergstr. 11, 48149, Münster, Germany.
| | - Andreas Faust
- European Institute for Molecular Imaging, Waldeyerstr. 15, 48149, Münster, Germany.
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50
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Huang W, Liao JL. Catalytic Mechanism of the Maltose Transporter Hydrolyzing ATP. Biochemistry 2015; 55:224-31. [PMID: 26666844 DOI: 10.1021/acs.biochem.5b00970] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We use quantum mechanical and molecular mechanical (QM/MM) simulations to study ATP hydrolysis catalyzed by the maltose transporter. This protein is a prototypical member of a large family that consists of ATP-binding cassette (ABC) transporters. The ABC proteins catalyze ATP hydrolysis to perform a variety of biological functions. Despite extensive research efforts, the precise molecular mechanism of ATP hydrolysis catalyzed by the ABC enzymes remains elusive. In this work, the reaction pathway for ATP hydrolysis in the maltose transporter is evaluated using a QM/MM implementation of the nudged elastic band method without presuming reaction coordinates. The potential of mean force along the reaction pathway is obtained with an activation free energy of 19.2 kcal/mol in agreement with experiments. The results demonstrate that the reaction proceeds via a dissociative-like pathway with a trigonal bipyramidal transition state in which the cleavage of the γ-phosphate P-O bond occurs and the O-H bond of the lytic water molecule is not yet broken. Our calculations clearly show that the Walker B glutamate as well as the switch histidine stabilizes the transition state via electrostatic interactions rather than serving as a catalytic base. The results are consistent with biochemical and structural experiments, providing novel insight into the molecular mechanism of ATP hydrolysis in the ABC proteins.
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Affiliation(s)
- Wenting Huang
- Department of Chemical Physics, University of Science and Technology of China , 96 Jinzhai Road, Hefei, Anhui Province, People's Republic of China 230026
| | - Jie-Lou Liao
- Department of Chemical Physics, University of Science and Technology of China , 96 Jinzhai Road, Hefei, Anhui Province, People's Republic of China 230026
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