1
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Newstead S, Parker J, Deme J, Lichtinger S, Kuteyi G, Biggin P, Lea S. Structural basis for antibiotic transport and inhibition in PepT2, the mammalian proton-coupled peptide transporter. RESEARCH SQUARE 2024:rs.3.rs-4435259. [PMID: 38903084 PMCID: PMC11188089 DOI: 10.21203/rs.3.rs-4435259/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/22/2024]
Abstract
The uptake and elimination of beta-lactam antibiotics in the human body are facilitated by the proton-coupled peptide transporters PepT1 (SLC15A1) and PepT2 (SLC15A2). The mechanism by which SLC15 family transporters recognize and discriminate between different drug classes and dietary peptides remains unclear, hampering efforts to improve antibiotic pharmacokinetics through targeted drug design and delivery. Here, we present cryo-EM structures of the mammalian proton-coupled peptide transporter, PepT2, in complex with the widely used beta-lactam antibiotics cefadroxil, amoxicillin and cloxacillin. Our structures, combined with pharmacophore mapping, molecular dynamics simulations and biochemical assays, establish the mechanism of antibiotic recognition and the important role of protonation in drug binding and transport.
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Affiliation(s)
| | | | - Justin Deme
- National Cancer Institute, National Institutes of Health
| | | | | | | | - Susan Lea
- Center for Structural Biology, Center for Cancer Research, National Cancer Institute
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2
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Feng J, Zhu C, Cao J, Liu C, Zhang J, Cao F, Zhou X. Genome-wide identification and expression analysis of the NRT genes in Ginkgo biloba under nitrate treatment reveal the potential roles during calluses browning. BMC Genomics 2023; 24:633. [PMID: 37872493 PMCID: PMC10594704 DOI: 10.1186/s12864-023-09732-4] [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: 05/15/2023] [Accepted: 10/11/2023] [Indexed: 10/25/2023] Open
Abstract
Nitrate is a primary nitrogen source for plant growth, and previous studies have indicated a correlation between nitrogen and browning. Nitrate transporters (NRTs) are crucial in nitrate allocation. Here, we utilized a genome-wide approach to identify and analyze the expression pattern of 74 potential GbNRTs under nitrate treatments during calluses browning in Ginkgo, including 68 NITRATE TRANSPORTER 1 (NRT1)/PEPTIDE TRANSPORTER (PTR) (NPF), 4 NRT2 and 2 NRT3. Conserved domains, motifs, phylogeny, and cis-acting elements (CREs) were analyzed to demonstrate the evolutionary conservation and functional diversity of GbNRTs. Our analysis showed that the NPF family was divided into eight branches, with the GbNPF2 and GbNPF6 subfamilies split into three groups. Each GbNRT contained 108-214 CREs of 19-36 types, especially with binding sites of auxin and transcription factors v-myb avian myeloblastosis viral oncogene homolog (MYB) and basic helix-loop-helix (bHLH). The E1X1X2E2R motif had significant variations in GbNPFs, indicating changes in the potential dynamic proton transporting ability. The expression profiles of GbNRTs indicated that they may function in regulating nitrate uptake and modulating the signaling of auxin and polyphenols biosynthesis, thereby affecting browning in Ginkgo callus induction. These findings provide a better understanding of the role of NRTs during NO3- uptake and utilization in vitro culture, which is crucial to prevent browning and develop an efficient regeneration and suspension production system in Ginkgo.
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Affiliation(s)
- Jin Feng
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Lin'an, Hangzhou, 311300, Zhejiang, China
| | - Can Zhu
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Lin'an, Hangzhou, 311300, Zhejiang, China
| | - Jiaqi Cao
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Lin'an, Hangzhou, 311300, Zhejiang, China
| | - Chen Liu
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Lin'an, Hangzhou, 311300, Zhejiang, China
| | - Jiaqi Zhang
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Lin'an, Hangzhou, 311300, Zhejiang, China
| | - Fuliang Cao
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Lin'an, Hangzhou, 311300, Zhejiang, China
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, Nanjing, 210037, China
| | - Xiaohong Zhou
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Lin'an, Hangzhou, 311300, Zhejiang, China.
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3
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Kotov V, Killer M, Jungnickel KEJ, Lei J, Finocchio G, Steinke J, Bartels K, Strauss J, Dupeux F, Humm AS, Cornaciu I, Márquez JA, Pardon E, Steyaert J, Löw C. Plasticity of the binding pocket in peptide transporters underpins promiscuous substrate recognition. Cell Rep 2023; 42:112831. [PMID: 37467108 DOI: 10.1016/j.celrep.2023.112831] [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: 02/15/2023] [Revised: 06/09/2023] [Accepted: 07/03/2023] [Indexed: 07/21/2023] Open
Abstract
Proton-dependent oligopeptide transporters (POTs) are promiscuous transporters of the major facilitator superfamily that constitute the main route of entry for a wide range of dietary peptides and orally administrated peptidomimetic drugs. Given their clinical and pathophysiological relevance, several POT homologs have been studied extensively at the structural and molecular level. However, the molecular basis of recognition and transport of diverse peptide substrates has remained elusive. We present 14 X-ray structures of the bacterial POT DtpB in complex with chemically diverse di- and tripeptides, providing novel insights into the plasticity of the conserved central binding cavity. We analyzed binding affinities for more than 80 peptides and monitored uptake by a fluorescence-based transport assay. To probe whether all 8400 natural di- and tripeptides can bind to DtpB, we employed state-of-the-art molecular docking and machine learning and conclude that peptides with compact hydrophobic residues are the best DtpB binders.
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Affiliation(s)
- Vadim Kotov
- Center for Structural Systems Biology (CSSB), Notkestraße 85, 22607 Hamburg, Germany; European Molecular Biology Laboratory (EMBL) Hamburg, Notkestraße 85, 22607 Hamburg, Germany
| | - Maxime Killer
- Center for Structural Systems Biology (CSSB), Notkestraße 85, 22607 Hamburg, Germany; European Molecular Biology Laboratory (EMBL) Hamburg, Notkestraße 85, 22607 Hamburg, Germany; Faculty of Biosciences, Collaboration for Joint PhD Degree between EMBL and Heidelberg University, Hamburg, Germany
| | - Katharina E J Jungnickel
- Center for Structural Systems Biology (CSSB), Notkestraße 85, 22607 Hamburg, Germany; European Molecular Biology Laboratory (EMBL) Hamburg, Notkestraße 85, 22607 Hamburg, Germany
| | - Jian Lei
- Center for Structural Systems Biology (CSSB), Notkestraße 85, 22607 Hamburg, Germany; European Molecular Biology Laboratory (EMBL) Hamburg, Notkestraße 85, 22607 Hamburg, Germany; State Key Laboratory of Biotherapy and Cancer Center, Sichuan University, No. 17, Block 3, Southern Renmin Road, Chengdu, Sichuan 610041, People's Republic of China
| | - Giada Finocchio
- Center for Structural Systems Biology (CSSB), Notkestraße 85, 22607 Hamburg, Germany; European Molecular Biology Laboratory (EMBL) Hamburg, Notkestraße 85, 22607 Hamburg, Germany
| | - Josi Steinke
- Center for Structural Systems Biology (CSSB), Notkestraße 85, 22607 Hamburg, Germany; European Molecular Biology Laboratory (EMBL) Hamburg, Notkestraße 85, 22607 Hamburg, Germany
| | - Kim Bartels
- Center for Structural Systems Biology (CSSB), Notkestraße 85, 22607 Hamburg, Germany; European Molecular Biology Laboratory (EMBL) Hamburg, Notkestraße 85, 22607 Hamburg, Germany
| | - Jan Strauss
- Center for Structural Systems Biology (CSSB), Notkestraße 85, 22607 Hamburg, Germany; European Molecular Biology Laboratory (EMBL) Hamburg, Notkestraße 85, 22607 Hamburg, Germany
| | - Florine Dupeux
- European Molecular Biology Laboratory (EMBL) Grenoble, 71 Avenue des Martyrs CS 90181, 38042 Grenoble Cedex 9, France
| | - Anne-Sophie Humm
- European Molecular Biology Laboratory (EMBL) Grenoble, 71 Avenue des Martyrs CS 90181, 38042 Grenoble Cedex 9, France
| | - Irina Cornaciu
- European Molecular Biology Laboratory (EMBL) Grenoble, 71 Avenue des Martyrs CS 90181, 38042 Grenoble Cedex 9, France
| | - José A Márquez
- European Molecular Biology Laboratory (EMBL) Grenoble, 71 Avenue des Martyrs CS 90181, 38042 Grenoble Cedex 9, France
| | - Els Pardon
- Structural Biology Brussels, Vrije Universiteit Brussel (VUB), 1050 Brussels, Belgium; VIB-VUB Center for Structural Biology, VIB, 1050 Brussels, Belgium
| | - Jan Steyaert
- Structural Biology Brussels, Vrije Universiteit Brussel (VUB), 1050 Brussels, Belgium; VIB-VUB Center for Structural Biology, VIB, 1050 Brussels, Belgium
| | - Christian Löw
- Center for Structural Systems Biology (CSSB), Notkestraße 85, 22607 Hamburg, Germany; European Molecular Biology Laboratory (EMBL) Hamburg, Notkestraße 85, 22607 Hamburg, Germany.
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4
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Ozhelvaci F, Steczkiewicz K. Identification and Classification of Papain-like Cysteine Proteinases. J Biol Chem 2023:104801. [PMID: 37164157 DOI: 10.1016/j.jbc.2023.104801] [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: 01/23/2023] [Revised: 04/11/2023] [Accepted: 05/05/2023] [Indexed: 05/12/2023] Open
Abstract
Papain-like cysteine peptidases form a big and highly diverse superfamily of proteins involved in many important biological functions, such as protein turnover, deubiquitination, tissue remodeling, blood clotting, virulence, defense, and cell wall remodeling. High sequence and structure diversity observed within these proteins hinders their comprehensive classification as well as the identification of new representatives. Moreover, in general protein databases, many families already classified as papain-like lack details regarding their mechanism of action or biological function. Here, we use transitive remote homology searches and 3D modeling to newly classify 21 families to the papain-like cysteine peptidase superfamily. We attempt to predict their biological function, and provide structural chacterization of 89 protein clusters defined based on sequence similarity altogether spanning 106 papain-like families. Moreover, we systematically discuss observed diversity in sequences, structures, and catalytic sites. Eventually, we expand the list of human papain-related proteins by seven representatives, including dopamine receptor-interacting protein (DRIP1) as potential deubiquitinase, and centriole duplication regulating CEP76 as retaining catalytically active peptidase-like domain. The presented results not only provide structure-based rationales to already existing peptidase databases but also may inspire further experimental research focused on peptidase-related biological processes.
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Affiliation(s)
- Fatih Ozhelvaci
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
| | - Kamil Steczkiewicz
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
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5
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Killer M, Finocchio G, Mertens HDT, Svergun DI, Pardon E, Steyaert J, Löw C. Cryo-EM Structure of an Atypical Proton-Coupled Peptide Transporter: Di- and Tripeptide Permease C. Front Mol Biosci 2022; 9:917725. [PMID: 35898305 PMCID: PMC9309889 DOI: 10.3389/fmolb.2022.917725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Accepted: 06/16/2022] [Indexed: 11/16/2022] Open
Abstract
Proton-coupled Oligopeptide Transporters (POTs) of the Major Facilitator Superfamily (MFS) mediate the uptake of short di- and tripeptides in all phyla of life. POTs are thought to constitute the most promiscuous class of MFS transporters, with the potential to transport more than 8400 unique substrates. Over the past two decades, transport assays and biophysical studies have shown that various orthologues and paralogues display differences in substrate selectivity. The E. coli genome codes for four different POTs, known as Di- and tripeptide permeases A-D (DtpA-D). DtpC was shown previously to favor positively charged peptides as substrates. In this study, we describe, how we determined the structure of the 53 kDa DtpC by cryogenic electron microscopy (cryo-EM), and provide structural insights into the ligand specificity of this atypical POT. We collected and analyzed data on the transporter fused to split superfolder GFP (split sfGFP), in complex with a 52 kDa Pro-macrobody and with a 13 kDa nanobody. The latter sample was more stable, rigid and a significant fraction dimeric, allowing us to reconstruct a 3D volume of DtpC at a resolution of 2.7 Å. This work provides a molecular explanation for the selectivity of DtpC, and highlights the value of small and rigid fiducial markers such as nanobodies for structure determination of low molecular weight integral membrane proteins lacking soluble domains.
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Affiliation(s)
- Maxime Killer
- Centre for Structural Systems Biology (CSSB), Hamburg, Germany
- Molecular Biology Laboratory (EMBL), Hamburg Unit C/o Deutsches Elektronen Synchrotron (DESY), Hamburg, Germany
- Collaboration for Joint PhD Degree Between EMBL and Heidelberg University, Faculty of Biosciences, Heidelberg, Germany
| | - Giada Finocchio
- Centre for Structural Systems Biology (CSSB), Hamburg, Germany
- Molecular Biology Laboratory (EMBL), Hamburg Unit C/o Deutsches Elektronen Synchrotron (DESY), Hamburg, Germany
| | - Haydyn D. T. Mertens
- Molecular Biology Laboratory (EMBL), Hamburg Unit C/o Deutsches Elektronen Synchrotron (DESY), Hamburg, Germany
| | - Dmitri I. Svergun
- Molecular Biology Laboratory (EMBL), Hamburg Unit C/o Deutsches Elektronen Synchrotron (DESY), Hamburg, Germany
| | - Els Pardon
- Structural Biology Brussels, Vrije Universiteit Brussel (VUB), Brussels, Belgium
- VIB-VUB Center for Structural Biology, VIB, Brussels, Belgium
| | - Jan Steyaert
- Structural Biology Brussels, Vrije Universiteit Brussel (VUB), Brussels, Belgium
- VIB-VUB Center for Structural Biology, VIB, Brussels, Belgium
| | - Christian Löw
- Centre for Structural Systems Biology (CSSB), Hamburg, Germany
- Molecular Biology Laboratory (EMBL), Hamburg Unit C/o Deutsches Elektronen Synchrotron (DESY), Hamburg, Germany
- *Correspondence: Christian Löw,
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6
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Extracellular domain of PepT1 interacts with TM1 to facilitate substrate transport. Structure 2022; 30:1035-1041.e3. [PMID: 35580608 PMCID: PMC10404463 DOI: 10.1016/j.str.2022.04.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2022] [Revised: 04/07/2022] [Accepted: 04/21/2022] [Indexed: 11/20/2022]
Abstract
Mammalian peptide transporters, PepT1 and PepT2, mediate uptake of small peptides and are essential for their absorption. PepT also mediates absorption of many drugs and prodrugs to enhance their bioavailability. PepT has twelve transmembrane (TM) helices that fold into an N-terminal domain (NTD, TM1-6) and a C-terminal domain (CTD, TM7-12) and has a large extracellular domain (ECD) between TM9-10. It is well recognized that peptide transport requires movements of the NTD and CTD, but the role of the ECD in PepT1 remains unclear. Here we report the structure of horse PepT1 encircled in lipid nanodiscs and captured in the inward-open apo conformation. The structure shows that the ECD bridges the NTD and CTD by interacting with TM1. Deletion of ECD or mutations to the ECD-TM1 interface impairs the transport activity. These results demonstrate an important role of ECD in PepT1 and enhance our understanding of the transport mechanism in PepT1.
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7
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Stauffer M, Jeckelmann JM, Ilgü H, Ucurum Z, Boggavarapu R, Fotiadis D. Peptide transporter structure reveals binding and action mechanism of a potent PEPT1 and PEPT2 inhibitor. Commun Chem 2022; 5:23. [PMID: 36697632 PMCID: PMC9814568 DOI: 10.1038/s42004-022-00636-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Accepted: 01/27/2022] [Indexed: 01/28/2023] Open
Abstract
Inhibitors for membrane transporters have been shown to be indispensable as drugs and tool compounds. The proton-dependent oligopeptide transporters PEPT1 and PEPT2 from the SLC15 family play important roles in human and mammalian physiology. With Lys[Z(NO2)]-Val (LZNV), a modified Lys-Val dipeptide, a potent transport inhibitor for PEPT1 and PEPT2 is available. Here we present the crystal structure of the peptide transporter YePEPT in complex with LZNV. The structure revealed the molecular interactions for inhibitor binding and a previously undescribed mostly hydrophobic pocket, the PZ pocket, involved in interaction with LZNV. Comparison with a here determined ligand-free structure of the transporter unveiled that the initially absent PZ pocket emerges through conformational changes upon inhibitor binding. The provided biochemical and structural information constitutes an important framework for the mechanistic understanding of inhibitor binding and action in proton-dependent oligopeptide transporters.
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Affiliation(s)
- Mirko Stauffer
- grid.5734.50000 0001 0726 5157Institute of Biochemistry and Molecular Medicine, and Swiss National Centre of Competence in Research (NCCR) TransCure, University of Bern, Bern, Switzerland
| | - Jean-Marc Jeckelmann
- grid.5734.50000 0001 0726 5157Institute of Biochemistry and Molecular Medicine, and Swiss National Centre of Competence in Research (NCCR) TransCure, University of Bern, Bern, Switzerland
| | - Hüseyin Ilgü
- grid.5734.50000 0001 0726 5157Institute of Biochemistry and Molecular Medicine, and Swiss National Centre of Competence in Research (NCCR) TransCure, University of Bern, Bern, Switzerland
| | - Zöhre Ucurum
- grid.5734.50000 0001 0726 5157Institute of Biochemistry and Molecular Medicine, and Swiss National Centre of Competence in Research (NCCR) TransCure, University of Bern, Bern, Switzerland
| | - Rajendra Boggavarapu
- grid.5734.50000 0001 0726 5157Institute of Biochemistry and Molecular Medicine, and Swiss National Centre of Competence in Research (NCCR) TransCure, University of Bern, Bern, Switzerland ,grid.67105.350000 0001 2164 3847Present Address: Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, OH USA
| | - Dimitrios Fotiadis
- grid.5734.50000 0001 0726 5157Institute of Biochemistry and Molecular Medicine, and Swiss National Centre of Competence in Research (NCCR) TransCure, University of Bern, Bern, Switzerland
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8
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Killer M, Wald J, Pieprzyk J, Marlovits TC, Löw C. Structural snapshots of human PepT1 and PepT2 reveal mechanistic insights into substrate and drug transport across epithelial membranes. SCIENCE ADVANCES 2021; 7:eabk3259. [PMID: 34730990 PMCID: PMC8565842 DOI: 10.1126/sciadv.abk3259] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
The uptake of peptides in mammals plays a crucial role in nutrition and inflammatory diseases. This process is mediated by promiscuous transporters of the solute carrier family 15, which form part of the major facilitator superfamily. Besides the uptake of short peptides, peptide transporter 1 (PepT1) is a highly abundant drug transporter in the intestine and represents a major route for oral drug delivery. PepT2 also allows renal drug reabsorption from ultrafiltration and brain-to-blood efflux of neurotoxic compounds. Here, we present cryogenic electron microscopy (cryo-EM) structures of human PepT1 and PepT2 captured in four different states throughout the transport cycle. The structures reveal the architecture of human peptide transporters and provide mechanistic insights into substrate recognition and conformational transitions during transport. This may support future drug design efforts to increase the bioavailability of different drugs in the human body.
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Affiliation(s)
- Maxime Killer
- Centre for Structural Systems Biology (CSSB), Notkestrasse 85, D-22607 Hamburg, Germany
- European Molecular Biology Laboratory (EMBL), Hamburg Unit c/o Deutsches Elektronen Synchrotron (DESY), Notkestrasse 85, D-22607 Hamburg, Germany
- Collaboration for joint PhD degree between EMBL and Heidelberg University, Faculty of Biosciences, Faculty of Biosciences, Im Neuenheimer Feld 234, D-69120 Heidelberg, Germany
| | - Jiri Wald
- Centre for Structural Systems Biology (CSSB), Notkestrasse 85, D-22607 Hamburg, Germany
- Institute of Structural and Systems Biology, University Medical Center Hamburg-Eppendorf, Notkestrasse 85, D-22607 Hamburg, Germany
- Deutsches Elektronen Synchrotron (DESY), Notkestrasse 85, D-22607 Hamburg, Germany
| | - Joanna Pieprzyk
- Centre for Structural Systems Biology (CSSB), Notkestrasse 85, D-22607 Hamburg, Germany
- European Molecular Biology Laboratory (EMBL), Hamburg Unit c/o Deutsches Elektronen Synchrotron (DESY), Notkestrasse 85, D-22607 Hamburg, Germany
| | - Thomas C. Marlovits
- Centre for Structural Systems Biology (CSSB), Notkestrasse 85, D-22607 Hamburg, Germany
- Institute of Structural and Systems Biology, University Medical Center Hamburg-Eppendorf, Notkestrasse 85, D-22607 Hamburg, Germany
- Deutsches Elektronen Synchrotron (DESY), Notkestrasse 85, D-22607 Hamburg, Germany
| | - Christian Löw
- Centre for Structural Systems Biology (CSSB), Notkestrasse 85, D-22607 Hamburg, Germany
- European Molecular Biology Laboratory (EMBL), Hamburg Unit c/o Deutsches Elektronen Synchrotron (DESY), Notkestrasse 85, D-22607 Hamburg, Germany
- Corresponding author.
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9
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Immadisetty K, Moradi M. Mechanistic Picture for Chemomechanical Coupling in a Bacterial Proton-Coupled Oligopeptide Transporter from Streptococcus Thermophilus. J Phys Chem B 2021; 125:9738-9750. [PMID: 34424716 DOI: 10.1021/acs.jpcb.1c03982] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Proton-coupled oligopeptide transporters (POTs) use the proton electrochemical gradient to transport peptides across the cell membrane. Despite the significant biological and biomedical relevance of these proteins, a detailed mechanistic picture for chemomechanical couplings involved in substrate/proton transport and protein structural changes is missing. Therefore, we performed microsecond-level molecular dynamics simulations of bacterial POT PepTSt, which shares ∼80% sequence identity with the human POT, PepT1, in the substrate-binding region. Three different conformational states of PepTSt were simulated, including (i) occluded, apo, (ii) inward-facing, apo, and (iii) inward-facingoccluded, Leu-Ala bound. We propose that the interaction of R33 with E299 and E300 acts as a conformational switch (i.e., to trigger the conformational change from an inward- to outward-facing state) in the substrate transport. Additionally, we propose that E299 and E400 disengage from interacting with the substrate either through protonation or through coordination with a cation for the substrate to get transported. This study provides clues to understand the chemomechanical couplings in POTs and paves the way to decipher the molecular-level underpinnings of the structure-function relationship in this important family of transporters.
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Affiliation(s)
| | - Mahmoud Moradi
- University of Arkansas, Fayetteville, Arkansas 72701, United States
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10
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Drew D, North RA, Nagarathinam K, Tanabe M. Structures and General Transport Mechanisms by the Major Facilitator Superfamily (MFS). Chem Rev 2021; 121:5289-5335. [PMID: 33886296 PMCID: PMC8154325 DOI: 10.1021/acs.chemrev.0c00983] [Citation(s) in RCA: 157] [Impact Index Per Article: 52.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Indexed: 12/12/2022]
Abstract
The major facilitator superfamily (MFS) is the largest known superfamily of secondary active transporters. MFS transporters are responsible for transporting a broad spectrum of substrates, either down their concentration gradient or uphill using the energy stored in the electrochemical gradients. Over the last 10 years, more than a hundred different MFS transporter structures covering close to 40 members have provided an atomic framework for piecing together the molecular basis of their transport cycles. Here, we summarize the remarkable promiscuity of MFS members in terms of substrate recognition and proton coupling as well as the intricate gating mechanisms undergone in achieving substrate translocation. We outline studies that show how residues far from the substrate binding site can be just as important for fine-tuning substrate recognition and specificity as those residues directly coordinating the substrate, and how a number of MFS transporters have evolved to form unique complexes with chaperone and signaling functions. Through a deeper mechanistic description of glucose (GLUT) transporters and multidrug resistance (MDR) antiporters, we outline novel refinements to the rocker-switch alternating-access model, such as a latch mechanism for proton-coupled monosaccharide transport. We emphasize that a full understanding of transport requires an elucidation of MFS transporter dynamics, energy landscapes, and the determination of how rate transitions are modulated by lipids.
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Affiliation(s)
- David Drew
- Department
of Biochemistry and Biophysics, Stockholm
University, SE 106 91 Stockholm, Sweden
| | - Rachel A. North
- Department
of Biochemistry and Biophysics, Stockholm
University, SE 106 91 Stockholm, Sweden
| | - Kumar Nagarathinam
- Center
of Structural and Cell Biology in Medicine, Institute of Biochemistry, University of Lübeck, D-23538, Lübeck, Germany
| | - Mikio Tanabe
- Structural
Biology Research Center, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), Oho 1-1, Tsukuba, Ibaraki 305-0801, Japan
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11
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Santin A, Caputi L, Longo A, Chiurazzi M, Ribera d'Alcalà M, Russo MT, Ferrante MI, Rogato A. Integrative omics identification, evolutionary and structural analysis of low affinity nitrate transporters in diatoms, diNPFs. Open Biol 2021; 11:200395. [PMID: 33823659 PMCID: PMC8025304 DOI: 10.1098/rsob.200395] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Diatoms are one of the major and most diverse groups of phytoplankton, with chimeric genomes harbouring a combination of genes of bacterial, animal and plant origin. They have developed sophisticated mechanisms to face environmental variations. In marine environments, nutrients concentration shows significant temporal and spatial variability, influencing phytoplankton growth. Among nutrients, nitrogen, present at micromolar levels, is often a limiting resource. Here, we report a comprehensive characterization of the Nitrate Transporter 1/Peptide Transporter Family (NPF) in diatoms, diNPFs. NPFs are well characterized in many organisms where they recognize a broad range of substrates, ranging from short-chained di- and tri-peptides in bacteria, fungi and mammals to a wide variety of molecules including nitrate in higher plants. Scarce information is available for diNPFs. We integrated-omics, phylogenetic, structural and expression analyses, to infer information on their role in diatoms. diNPF genes diverged to produce two distinct clades with strong sequence and structural homology with either bacterial or plant NPFs, with different predicted sub-cellular localization, suggesting that the divergence resulted in functional diversification. Moreover, transcription analysis of diNPF genes under different laboratory and environmental growth conditions suggests that diNPF diversification led to genetic adaptations that might contribute to diatoms ability to flourish in diverse environmental conditions.
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Affiliation(s)
- Anna Santin
- Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Naples, Italy
| | - Luigi Caputi
- Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Naples, Italy
| | - Antonella Longo
- BioDiscovery Institute, Denton, TX, USA.,Department of Biological Sciences, University of North Texas, Denton, TX, USA
| | - Maurizio Chiurazzi
- Institute of Biosciences and BioResources, CNR, Via P. Castellino 111, 80131 Naples, Italy
| | | | | | | | - Alessandra Rogato
- Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Naples, Italy.,Institute of Biosciences and BioResources, CNR, Via P. Castellino 111, 80131 Naples, Italy
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12
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Lasitza‐Male T, Bartels K, Jungwirth J, Wiggers F, Rosenblum G, Hofmann H, Löw C. Membrane Chemistry Tunes the Structure of a Peptide Transporter. Angew Chem Int Ed Engl 2020; 59:19121-19128. [PMID: 32744783 PMCID: PMC7590137 DOI: 10.1002/anie.202008226] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Indexed: 01/02/2023]
Abstract
Membrane proteins require lipid bilayers for function. While lipid compositions reach enormous complexities, high-resolution structures are usually obtained in artificial detergents. To understand whether and how lipids guide membrane protein function, we use single-molecule FRET to probe the dynamics of DtpA, a member of the proton-coupled oligopeptide transporter (POT) family, in various lipid environments. We show that detergents trap DtpA in a dynamic ensemble with cytoplasmic opening. Only reconstitutions in more native environments restore cooperativity, allowing an opening to the extracellular side and a sampling of all relevant states. Bilayer compositions tune the abundance of these states. A novel state with an extreme cytoplasmic opening is accessible in bilayers with anionic head groups. Hence, chemical diversity of membranes translates into structural diversity, with the current POT structures only sampling a portion of the full structural space.
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Affiliation(s)
- Tanya Lasitza‐Male
- Department of Structural BiologyWeizmann Institute of ScienceHerzl St. 2347610001RehovotIsrael
| | - Kim Bartels
- Centre for Structural Systems Biology (CSSB)DESY and European Molecular Biology Laboratory HamburgNotkestrasse 8522607HamburgGermany
| | - Jakub Jungwirth
- Department of Chemical and Biological PhysicsWeizmann Institute of ScienceHerzl St. 2347610001RehovotIsrael
| | - Felix Wiggers
- Department of Structural BiologyWeizmann Institute of ScienceHerzl St. 2347610001RehovotIsrael
| | - Gabriel Rosenblum
- Department of Structural BiologyWeizmann Institute of ScienceHerzl St. 2347610001RehovotIsrael
| | - Hagen Hofmann
- Department of Structural BiologyWeizmann Institute of ScienceHerzl St. 2347610001RehovotIsrael
| | - Christian Löw
- Centre for Structural Systems Biology (CSSB)DESY and European Molecular Biology Laboratory HamburgNotkestrasse 8522607HamburgGermany
- Department of Medical Biochemistry and BiophysicsKarolinska Institutet17177StockholmSweden
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13
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Lasitza‐Male T, Bartels K, Jungwirth J, Wiggers F, Rosenblum G, Hofmann H, Löw C. Membrane Chemistry Tunes the Structure of a Peptide Transporter. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202008226] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Tanya Lasitza‐Male
- Department of Structural Biology Weizmann Institute of Science Herzl St. 234 7610001 Rehovot Israel
| | - Kim Bartels
- Centre for Structural Systems Biology (CSSB) DESY and European Molecular Biology Laboratory Hamburg Notkestrasse 85 22607 Hamburg Germany
| | - Jakub Jungwirth
- Department of Chemical and Biological Physics Weizmann Institute of Science Herzl St. 234 7610001 Rehovot Israel
| | - Felix Wiggers
- Department of Structural Biology Weizmann Institute of Science Herzl St. 234 7610001 Rehovot Israel
| | - Gabriel Rosenblum
- Department of Structural Biology Weizmann Institute of Science Herzl St. 234 7610001 Rehovot Israel
| | - Hagen Hofmann
- Department of Structural Biology Weizmann Institute of Science Herzl St. 234 7610001 Rehovot Israel
| | - Christian Löw
- Centre for Structural Systems Biology (CSSB) DESY and European Molecular Biology Laboratory Hamburg Notkestrasse 85 22607 Hamburg Germany
- Department of Medical Biochemistry and Biophysics Karolinska Institutet 17177 Stockholm Sweden
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14
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High-throughput stability screening for detergent-solubilized membrane proteins. Sci Rep 2019; 9:10379. [PMID: 31316088 PMCID: PMC6637136 DOI: 10.1038/s41598-019-46686-8] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Accepted: 07/03/2019] [Indexed: 01/08/2023] Open
Abstract
Protein stability in detergent or membrane-like environments is the bottleneck for structural studies on integral membrane proteins (IMP). Irrespective of the method to study the structure of an IMP, detergent solubilization from the membrane is usually the first step in the workflow. Here, we establish a simple, high-throughput screening method to identify optimal detergent conditions for membrane protein stabilization. We apply differential scanning fluorimetry in combination with scattering upon thermal denaturation to study the unfolding of integral membrane proteins. Nine different prokaryotic and eukaryotic membrane proteins were used as test cases to benchmark our detergent screening method. Our results show that it is possible to measure the stability and solubility of IMPs by diluting them from their initial solubilization condition into different detergents. We were able to identify groups of detergents with characteristic stabilization and destabilization effects for selected targets. We further show that fos-choline and PEG family detergents may lead to membrane protein destabilization and unfolding. Finally, we determined thenmodynamic parameters that are important indicators of IMP stability. The described protocol allows the identification of conditions that are suitable for downstream handling of membrane proteins during purification.
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15
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Breyton C, Javed W, Vermot A, Arnaud CA, Hajjar C, Dupuy J, Petit-Hartlein I, Le Roy A, Martel A, Thépaut M, Orelle C, Jault JM, Fieschi F, Porcar L, Ebel C. Assemblies of lauryl maltose neopentyl glycol (LMNG) and LMNG-solubilized membrane proteins. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2019; 1861:939-957. [PMID: 30776334 DOI: 10.1016/j.bbamem.2019.02.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2018] [Revised: 02/08/2019] [Accepted: 02/08/2019] [Indexed: 12/11/2022]
Abstract
Laurylmaltose neopentylglycol (LMNG) bears two linked hydrophobic chains of equal length and two hydrophilic maltoside groups. It arouses a strong interest in the field of membrane protein biochemistry, since it was shown to efficiently solubilize and stabilize membrane proteins often better than the commonly used dodecylmaltopyranoside (DDM), and to allow structure determination of some challenging membrane proteins. However, LMNG was described to form large micelles, which could be unfavorable for structural purposes. We thus investigated its auto-assemblies and the association state of different membrane proteins solubilized in LMNG by analytical ultracentrifugation, size exclusion chromatography coupled to light scattering, centrifugation on sucrose gradient and/or small angle scattering. At high concentrations (in the mM range), LMNG forms long rods, and it stabilized the membrane proteins investigated herein, i.e. a bacterial multidrug transporter, BmrA; a prokaryotic analogous of the eukaryotic NADPH oxidases, SpNOX; an E. coli outer membrane transporter, FhuA; and the halobacterial bacteriorhodopsin, bR. BmrA, in the Apo and the vanadate-inhibited forms showed reduced kinetics of limited proteolysis in LMNG compared to DDM. Both SpNOX and BmrA display an increased specific activity in LMNG compared to DDM. The four proteins form LMNG complexes with their usual quaternary structure and with usual amount of bound detergent. No heterogeneous complexes related to the large micelle size of LMNG alone were observed. In conditions where LMNG forms assemblies of large size, FhuA crystals diffracting to 4.0 Å were obtained by vapor diffusion. LMNG large micelle size thus does not preclude membrane protein homogeneity and crystallization.
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Affiliation(s)
- Cécile Breyton
- Univ. Grenoble Alpes, CNRS, CEA, Institute for Structural Biology (IBS), 38000 Grenoble, France
| | - Waqas Javed
- Univ. Grenoble Alpes, CNRS, CEA, Institute for Structural Biology (IBS), 38000 Grenoble, France; University of Lyon, CNRS, UMR5086, Molecular Microbiology and Structural Biochemistry, IBCP, Lyon 69367, France
| | - Annelise Vermot
- Univ. Grenoble Alpes, CNRS, CEA, Institute for Structural Biology (IBS), 38000 Grenoble, France
| | - Charles-Adrien Arnaud
- Univ. Grenoble Alpes, CNRS, CEA, Institute for Structural Biology (IBS), 38000 Grenoble, France
| | - Christine Hajjar
- Univ. Grenoble Alpes, CNRS, CEA, Institute for Structural Biology (IBS), 38000 Grenoble, France
| | - Jérôme Dupuy
- Univ. Grenoble Alpes, CNRS, CEA, Institute for Structural Biology (IBS), 38000 Grenoble, France
| | - Isabelle Petit-Hartlein
- Univ. Grenoble Alpes, CNRS, CEA, Institute for Structural Biology (IBS), 38000 Grenoble, France
| | - Aline Le Roy
- Univ. Grenoble Alpes, CNRS, CEA, Institute for Structural Biology (IBS), 38000 Grenoble, France
| | - Anne Martel
- Institut Max Von Laue Paul Langevin, 38042 Grenoble, France
| | - Michel Thépaut
- Univ. Grenoble Alpes, CNRS, CEA, Institute for Structural Biology (IBS), 38000 Grenoble, France
| | - Cédric Orelle
- University of Lyon, CNRS, UMR5086, Molecular Microbiology and Structural Biochemistry, IBCP, Lyon 69367, France
| | - Jean-Michel Jault
- University of Lyon, CNRS, UMR5086, Molecular Microbiology and Structural Biochemistry, IBCP, Lyon 69367, France
| | - Franck Fieschi
- Univ. Grenoble Alpes, CNRS, CEA, Institute for Structural Biology (IBS), 38000 Grenoble, France
| | - Lionel Porcar
- Institut Max Von Laue Paul Langevin, 38042 Grenoble, France
| | - Christine Ebel
- Univ. Grenoble Alpes, CNRS, CEA, Institute for Structural Biology (IBS), 38000 Grenoble, France.
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16
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Ural-Blimke Y, Flayhan A, Strauss J, Rantos V, Bartels K, Nielsen R, Pardon E, Steyaert J, Kosinski J, Quistgaard EM, Löw C. Structure of Prototypic Peptide Transporter DtpA from E. coli in Complex with Valganciclovir Provides Insights into Drug Binding of Human PepT1. J Am Chem Soc 2019; 141:2404-2412. [DOI: 10.1021/jacs.8b11343] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Yonca Ural-Blimke
- Centre for Structural Systems Biology (CSSB), DESY and European Molecular Biology Laboratory Hamburg, Notkestrasse 85, D-22607 Hamburg, Germany
| | - Ali Flayhan
- Centre for Structural Systems Biology (CSSB), DESY and European Molecular Biology Laboratory Hamburg, Notkestrasse 85, D-22607 Hamburg, Germany
| | - Jan Strauss
- Centre for Structural Systems Biology (CSSB), DESY and European Molecular Biology Laboratory Hamburg, Notkestrasse 85, D-22607 Hamburg, Germany
| | - Vasileios Rantos
- Centre for Structural Systems Biology (CSSB), DESY and European Molecular Biology Laboratory Hamburg, Notkestrasse 85, D-22607 Hamburg, Germany
| | - Kim Bartels
- Centre for Structural Systems Biology (CSSB), DESY and European Molecular Biology Laboratory Hamburg, Notkestrasse 85, D-22607 Hamburg, Germany
| | - Rolf Nielsen
- Centre for Structural Systems Biology (CSSB), DESY and European Molecular Biology Laboratory Hamburg, Notkestrasse 85, D-22607 Hamburg, Germany
| | - Els Pardon
- Structural Biology Brussels, Vrije Universiteit Brussel (VUB), Brussels 1050, Belgium
- VIB-VUB Center for Structural Biology, VIB, Brussels 1050, Belgium
| | - Jan Steyaert
- Structural Biology Brussels, Vrije Universiteit Brussel (VUB), Brussels 1050, Belgium
- VIB-VUB Center for Structural Biology, VIB, Brussels 1050, Belgium
| | - Jan Kosinski
- Centre for Structural Systems Biology (CSSB), DESY and European Molecular Biology Laboratory Hamburg, Notkestrasse 85, D-22607 Hamburg, Germany
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Meyerhofstrasse 1, 69117 Heidelberg, Germany
| | - Esben M. Quistgaard
- Centre for Structural Systems Biology (CSSB), DESY and European Molecular Biology Laboratory Hamburg, Notkestrasse 85, D-22607 Hamburg, Germany
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Scheeles väg 2, SE-17177 Stockholm, Sweden
- Department of Molecular Biology and Genetics − DANDRITE, Gustav Wieds Vej 10, Aarhus University, DK-8000 Aarhus C, Denmark
| | - Christian Löw
- Centre for Structural Systems Biology (CSSB), DESY and European Molecular Biology Laboratory Hamburg, Notkestrasse 85, D-22607 Hamburg, Germany
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Scheeles väg 2, SE-17177 Stockholm, Sweden
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17
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Abstract
Transport of solutes across biological membranes is essential for cellular life. This process is mediated by membrane transport proteins which move nutrients, waste products, certain drugs and ions into and out of cells. Secondary active transporters couple the transport of substrates against their concentration gradients with the transport of other solutes down their concentration gradients. The alternating access model of membrane transporters and the coupling mechanism of secondary active transporters are introduced in this book chapter. Structural studies have identified typical protein folds for transporters that we exemplify by the major facilitator superfamily (MFS) and LeuT folds. Finally, substrate binding and substrate translocation of the transporters LacY of the MFS and AdiC of the amino acid-polyamine-organocation (APC) superfamily are described.
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Affiliation(s)
- Patrick D Bosshart
- Swiss National Centre of Competence in Research (NCCR) TransCure, Institute of Biochemistry and Molecular Medicine, University of Bern, Bühlstrasse 28, 3012, Bern, Switzerland
| | - Dimitrios Fotiadis
- Swiss National Centre of Competence in Research (NCCR) TransCure, Institute of Biochemistry and Molecular Medicine, University of Bern, Bühlstrasse 28, 3012, Bern, Switzerland.
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18
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Flayhan A, Mertens HDT, Ural-Blimke Y, Martinez Molledo M, Svergun DI, Löw C. Saposin Lipid Nanoparticles: A Highly Versatile and Modular Tool for Membrane Protein Research. Structure 2018; 26:345-355.e5. [PMID: 29413323 PMCID: PMC5807053 DOI: 10.1016/j.str.2018.01.007] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Revised: 11/27/2017] [Accepted: 01/10/2018] [Indexed: 11/30/2022]
Abstract
Saposin-derived lipid nanoparticles (SapNPs) are a new alternative tool for membrane protein reconstitution. Here we demonstrate the potential and advantages of SapNPs. We show that SapA has the lowest lipid specificity for SapNP formation. These nanoparticles are modular and offer a tunable range of size and composition depending on the stoichiometric ratio of lipid and saposin components. They are stable and exhibit features typical of lipid-bilayer systems. Our data suggest that SapNPs are versatile and can adapt to membrane proteins of various sizes and architectures. Using SapA and various types of lipids we could reconstitute membrane proteins of different transmembrane cross-sectional areas (from 14 to 56 transmembrane α helices). SapNP-reconstituted proteins bound their respective ligands and were more heat stable compared with the detergent-solubilized form. Moreover, SapNPs encircle membrane proteins in a compact way, allowing structural investigations of small membrane proteins in a detergent-free environment using small-angle X-ray scattering. SapA shows the lowest lipid specificity for SapNP formation SapNPs are versatile and can adapt to MPs of various sizes and architectures SapNP-reconstituted MPs are more stable than in detergent SapNPs encapsulate MPs in a compact manner
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Affiliation(s)
- Ali Flayhan
- Centre for Structural Systems Biology (CSSB), DESY, Notkestrasse 85, 22607 Hamburg, Germany; European Molecular Biology Laboratory Hamburg, Notkestrasse 85, 22607 Hamburg, Germany
| | - Haydyn D T Mertens
- European Molecular Biology Laboratory Hamburg, Notkestrasse 85, 22607 Hamburg, Germany
| | - Yonca Ural-Blimke
- Centre for Structural Systems Biology (CSSB), DESY, Notkestrasse 85, 22607 Hamburg, Germany; European Molecular Biology Laboratory Hamburg, Notkestrasse 85, 22607 Hamburg, Germany
| | - Maria Martinez Molledo
- Centre for Structural Systems Biology (CSSB), DESY, Notkestrasse 85, 22607 Hamburg, Germany; European Molecular Biology Laboratory Hamburg, Notkestrasse 85, 22607 Hamburg, Germany
| | - Dmitri I Svergun
- European Molecular Biology Laboratory Hamburg, Notkestrasse 85, 22607 Hamburg, Germany
| | - Christian Löw
- Centre for Structural Systems Biology (CSSB), DESY, Notkestrasse 85, 22607 Hamburg, Germany; European Molecular Biology Laboratory Hamburg, Notkestrasse 85, 22607 Hamburg, Germany; Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Scheeles väg 2, 17177 Stockholm, Sweden.
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19
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Martinez Molledo M, Quistgaard EM, Löw C. Tripeptide binding in a proton-dependent oligopeptide transporter. FEBS Lett 2018; 592:3239-3247. [PMID: 30194725 PMCID: PMC6221056 DOI: 10.1002/1873-3468.13246] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 08/29/2018] [Accepted: 09/05/2018] [Indexed: 01/30/2023]
Abstract
Proton-dependent oligopeptide transporters (POTs) are important for the uptake of di-/tripeptides in many organisms and for drug transport in humans. The binding mode of dipeptides has been well described. However, it is still debated how tripeptides are recognized. Here, we show that tripeptides of the sequence Phe-Ala-Xxx bind with similar affinities as dipeptides to the POT transporter from Streptococcus thermophilus (PepTS t ). We furthermore determined a 2.3-Å structure of PepTS t in complex with Phe-Ala-Gln. The phenylalanine and alanine residues of the peptide adopt the same positions as previously observed for the Phe-Ala dipeptide, while the glutamine side chain extends into a hitherto uncharacterized pocket. This pocket is adaptable in size and can likely accommodate a wide variety of peptide side chains.
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Affiliation(s)
- Maria Martinez Molledo
- Centre for Structural Systems Biology (CSSB), DESY and European Molecular Biology Laboratory Hamburg, Hamburg, Germany
| | - Esben M Quistgaard
- Centre for Structural Systems Biology (CSSB), DESY and European Molecular Biology Laboratory Hamburg, Hamburg, Germany.,Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Christian Löw
- Centre for Structural Systems Biology (CSSB), DESY and European Molecular Biology Laboratory Hamburg, Hamburg, Germany.,Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
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20
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Multispecific Substrate Recognition in a Proton-Dependent Oligopeptide Transporter. Structure 2018; 26:467-476.e4. [PMID: 29429879 PMCID: PMC5845931 DOI: 10.1016/j.str.2018.01.005] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Revised: 11/22/2017] [Accepted: 01/10/2018] [Indexed: 12/27/2022]
Abstract
Proton-dependent oligopeptide transporters (POTs) are important for uptake of dietary di- and tripeptides in many organisms, and in humans are also involved in drug absorption. These transporters accept a wide range of substrates, but the structural basis for how different peptide side chains are accommodated has so far remained obscure. Twenty-eight peptides were screened for binding to PepTSt from Streptococcus thermophilus, and structures were determined of PepTSt in complex with four physicochemically diverse dipeptides, which bind with millimolar affinity: Ala-Leu, Phe-Ala, Ala-Gln, and Asp-Glu. The structures show that PepTSt can adapt to different peptide side chains through movement of binding site residues and water molecules, and that a good fit can be further aided by adjustment of the position of the peptide itself. Finally, structures were also determined in complex with adventitiously bound HEPES, polyethylene glycol, and phosphate molecules, which further underline the adaptability of the binding site. Dipeptides can adapt their position to best fit the PepTSt binding site The PepTSt binding site can adapt its structure to best fit the dipeptides The water network in the PepTSt binding site can adapt to best fit the dipeptides Aromatic binding site residues play a role in conferring PepTSt multispecificity
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21
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Longo A, Miles NW, Dickstein R. Genome Mining of Plant NPFs Reveals Varying Conservation of Signature Motifs Associated With the Mechanism of Transport. FRONTIERS IN PLANT SCIENCE 2018; 9:1668. [PMID: 30564251 PMCID: PMC6288477 DOI: 10.3389/fpls.2018.01668] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Accepted: 10/26/2018] [Indexed: 05/04/2023]
Abstract
Nitrogen is essential for all living species and may be taken up from the environment in different forms like nitrate or peptides. In plants, members of a transporter family named NPFs transport nitrate and peptides across biological membranes. NPFs are phylogenetically related to a family of peptide transporters (PTRs) or proton-coupled oligopeptide transporters (POTs) that are evolutionarily conserved in all organisms except in Archaea. POTs are present in low numbers in bacteria, algae and animals. NPFs have expanded in plants and evolved to transport a wide range of substrates including phytohormones and glucosinolates. Functional studies have shown that most NPFs, like POTs, operate as symporters with simultaneous inwardly directed movement of protons. Here we focus on four structural features of NPFs/POTs/PTRs that have been shown by structural and functional studies to be essential to proton-coupled symport transport. The first two features are implicated in proton binding and transport: a conserved motif named ExxER/K, located in the first transmembrane helix (TMH1) and a D/E residue in TMH7 that has been observed in some bacterial and algal transporters. The third and fourth features are two inter-helical salt bridges between residues on TMH1 and TMH7 or TMH4 and TMH10. To understand if the mechanism of transport is conserved in NPFs with the expansion to novel substrates, we collected NPFs sequences from 42 plant genomes. Sequence alignment revealed that the ExxER/K motif is not strictly conserved and its conservation level is different in the NPF subfamilies. The proton binding site on TMH7 is missing in all NPFs with the exception of two NPFs from moss. The two moss NPFs also have a positively charged amino acid on TMH1 that can form the salt bridge with the TMH7 negative residue. None of the other NPFs we examined harbor residues that can form the TMH1-TMH7 salt bridge. In contrast, the amino acids required to form the TMH4-TMH10 salt bridge are highly conserved in NPFs, with some exceptions. These results support the need for further biochemical and structural studies of individual NPFs for a better understanding of the transport mechanism in this family of transporters.
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Affiliation(s)
- Antonella Longo
- BioDiscovery Institute, University of North Texas, Denton, TX, United States
- Department of Biological Sciences, University of North Texas, Denton, TX, United States
- *Correspondence: Antonella Longo,
| | - Nicholas W. Miles
- BioDiscovery Institute, University of North Texas, Denton, TX, United States
- Department of Biological Sciences, University of North Texas, Denton, TX, United States
| | - Rebecca Dickstein
- BioDiscovery Institute, University of North Texas, Denton, TX, United States
- Department of Biological Sciences, University of North Texas, Denton, TX, United States
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22
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Veith K, Martinez Molledo M, Almeida Hernandez Y, Josts I, Nitsche J, Löw C, Tidow H. Lipid-like Peptides can Stabilize Integral Membrane Proteins for Biophysical and Structural Studies. Chembiochem 2017; 18:1735-1742. [PMID: 28603929 PMCID: PMC5601290 DOI: 10.1002/cbic.201700235] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2017] [Indexed: 12/30/2022]
Abstract
A crucial bottleneck in membrane protein structural biology is the difficulty in identifying a detergent that can maintain the stability and functionality of integral membrane proteins (IMPs). Detergents are poor membrane mimics, and their common use in membrane protein crystallography may be one reason for the challenges in obtaining high-resolution crystal structures of many IMP families. Lipid-like peptides (LLPs) have detergent-like properties and have been proposed as alternatives for the solubilization of G protein-coupled receptors and other membrane proteins. Here, we systematically analyzed the stabilizing effect of LLPs on integral membrane proteins of different families. We found that LLPs could significantly stabilize detergent-solubilized IMPs in vitro. This stabilizing effect depended on the chemical nature of the LLP and the intrinsic stability of a particular IMP in the detergent. Our results suggest that screening a subset of LLPs is sufficient to stabilize a particular IMP, which can have a substantial impact on the crystallization and quality of the crystal.
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Affiliation(s)
- Katharina Veith
- The Hamburg Centre for Ultrafast ImagingDepartment of ChemistryInstitute for Biochemistry and Molecular BiologyUniversity of HamburgMartin-Luther-King-Platz 620146HamburgGermany
| | - Maria Martinez Molledo
- Centre for Structural Systems Biology (CSSB)DESY and European Molecular Biology Laboratory HamburgNotkestrasse 8522607HamburgGermany
| | - Yasser Almeida Hernandez
- The Hamburg Centre for Ultrafast ImagingDepartment of ChemistryInstitute for Biochemistry and Molecular BiologyUniversity of HamburgMartin-Luther-King-Platz 620146HamburgGermany
| | - Inokentijs Josts
- The Hamburg Centre for Ultrafast ImagingDepartment of ChemistryInstitute for Biochemistry and Molecular BiologyUniversity of HamburgMartin-Luther-King-Platz 620146HamburgGermany
| | - Julius Nitsche
- The Hamburg Centre for Ultrafast ImagingDepartment of ChemistryInstitute for Biochemistry and Molecular BiologyUniversity of HamburgMartin-Luther-King-Platz 620146HamburgGermany
| | - Christian Löw
- Centre for Structural Systems Biology (CSSB)DESY and European Molecular Biology Laboratory HamburgNotkestrasse 8522607HamburgGermany
- Department of Medical Biochemistry and BiophysicsKarolinska InstitutetScheeles väg 217177StockholmSweden
| | - Henning Tidow
- The Hamburg Centre for Ultrafast ImagingDepartment of ChemistryInstitute for Biochemistry and Molecular BiologyUniversity of HamburgMartin-Luther-King-Platz 620146HamburgGermany
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