1
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Aspholm EE, Lidman J, Burmann BM. Structural basis of substrate recognition and allosteric activation of the proapoptotic mitochondrial HtrA2 protease. Nat Commun 2024; 15:4592. [PMID: 38816423 DOI: 10.1038/s41467-024-48997-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Accepted: 05/14/2024] [Indexed: 06/01/2024] Open
Abstract
The mitochondrial serine protease HtrA2 is a human homolog of the Escherichia coli Deg-proteins exhibiting chaperone and proteolytic roles. HtrA2 is involved in both apoptotic regulation via its ability to degrade inhibitor-of-apoptosis proteins (IAPs), as well as in cellular maintenance as part of the cellular protein quality control machinery, by preventing the possible toxic accumulation of aggregated proteins. In this study, we use advanced solution NMR spectroscopy methods combined with biophysical characterization and biochemical assays to elucidate the crucial role of the substrate recognizing PDZ domain. This domain regulates the protease activity of HtrA2 by triggering an intricate allosteric network involving the regulatory loops of the protease domain. We further show that divalent metal ions can both positively and negatively modulate the activity of HtrA2, leading to a refined model of HtrA2 regulation within the apoptotic pathway.
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Affiliation(s)
- Emelie E Aspholm
- Department of Chemistry and Molecular Biology, University of Gothenburg, Göteborg, Sweden
- Wallenberg Centre for Molecular and Translational Medicine, University of Gothenburg, Göteborg, Sweden
| | - Jens Lidman
- Department of Chemistry and Molecular Biology, University of Gothenburg, Göteborg, Sweden
- Wallenberg Centre for Molecular and Translational Medicine, University of Gothenburg, Göteborg, Sweden
| | - Björn M Burmann
- Department of Chemistry and Molecular Biology, University of Gothenburg, Göteborg, Sweden.
- Wallenberg Centre for Molecular and Translational Medicine, University of Gothenburg, Göteborg, Sweden.
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2
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Goel S, Feisal MR, Danmaliki GI, Yu S, Liu PB, Bishop RE, West FG, Hwang PM. Probing amino acid side chains of the integral membrane protein PagP by solution NMR: Side chain immobilization facilitates association of secondary structures. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2024; 1866:184281. [PMID: 38218576 DOI: 10.1016/j.bbamem.2024.184281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Revised: 12/27/2023] [Accepted: 01/04/2024] [Indexed: 01/15/2024]
Abstract
Solution NMR spectroscopy of large protein systems is hampered by rapid signal decay, so most multidimensional studies focus on long-lived 1H-13C magnetization in methyl groups and/or backbone amide 1H-15N magnetization in an otherwise perdeuterated environment. Herein we demonstrate that it is possible to biosynthetically incorporate additional 1H-12C groups that possess long-lived magnetization using cost-effective partially deuterated or unlabeled amino acid precursors added to Escherichia coli growth media. This approach is applied to the outer membrane enzyme PagP in membrane-mimetic dodecylphosphocholine micelles. We were able to obtain chemical shift assignments for a majority of side chain 1H positions in PagP using nuclear Overhauser enhancements (NOEs) to connect them to previously assigned backbone 1H-15N groups and newly assigned 1H-13C methyl groups. Side chain methyl-to-aromatic NOEs were particularly important for confirming that the amphipathic α-helix of PagP packs against its eight-stranded β-barrel, as indicated by previous X-ray crystal structures. Interestingly, aromatic NOEs suggest that some aromatic residues in PagP that are buried in the membrane bilayer are highly mobile in the micellar environment, like Phe138 and Phe159. In contrast, Tyr87 in the middle of the bilayer is quite rigid, held in place by a hydrogen bonded network extending to the surface that resembles a classic catalytic triad: Tyr87-His67-Asp61. This hydrogen bonded arrangement of residues is not known to have any catalytic activity, but we postulate that its role is to immobilize Tyr87 to facilitate packing of the amphipathic α-helix against the β-barrel.
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Affiliation(s)
- Shaista Goel
- Department of Medicine, University of Alberta, Edmonton, AB, Canada
| | - M Rafid Feisal
- Department of Medicine, University of Alberta, Edmonton, AB, Canada
| | | | - Shaohui Yu
- Department of Chemistry, University of Alberta
| | - Philip B Liu
- Department of Medicine, University of Alberta, Edmonton, AB, Canada
| | - Russell E Bishop
- Department of Biochemistry and Biomedical Sciences, and Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, ON, Canada
| | | | - Peter M Hwang
- Department of Medicine, University of Alberta, Edmonton, AB, Canada; Department of Biochemistry, University of Alberta, Edmonton, AB, Canada.
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3
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Lidman J, Sallova Y, Matečko-Burmann I, Burmann BM. Structure and dynamics of the mitochondrial DNA-compaction factor Abf2 from S. cerevisiae. J Struct Biol 2023; 215:108008. [PMID: 37543301 DOI: 10.1016/j.jsb.2023.108008] [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: 03/27/2023] [Revised: 07/10/2023] [Accepted: 08/02/2023] [Indexed: 08/07/2023]
Abstract
Mitochondria are essential organelles that produce most of the energy via the oxidative phosphorylation (OXPHOS) system in all eukaryotic cells. Several essential subunits of the OXPHOS system are encoded by the mitochondrial genome (mtDNA) despite its small size. Defects in mtDNA maintenance and expression can lead to severe OXPHOS deficiencies and are amongst the most common causes of mitochondrial disease. The mtDNA is packaged as nucleoprotein structures, referred to as nucleoids. The conserved mitochondrial proteins, ARS-binding factor 2 (Abf2) in the budding yeast Saccharomyces cerevisiae (S. cerevisiae) and mitochondrial transcription factor A (TFAM) in mammals, are nucleoid associated proteins (NAPs) acting as condensing factors needed for packaging and maintenance of the mtDNA. Interestingly, gene knockout of Abf2 leads, in yeast, to the loss of mtDNA and respiratory growth, providing evidence for its crucial role. On a structural level, the condensing factors usually contain two DNA binding domains called high-mobility group boxes (HMG boxes). The co-operating mechanical activities of these domains are crucial in establishing the nucleoid architecture by bending the DNA strands. Here we used advanced solution NMR spectroscopy methods to characterize the dynamical properties of Abf2 together with its interaction with DNA. We find that the two HMG-domains react notably different to external cues like temperature and salt, indicating distinct functional properties. Biophysical characterizations show the pronounced difference of these domains upon DNA-binding, suggesting a refined picture of the Abf2 functional cycle.
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Affiliation(s)
- Jens Lidman
- Department of Chemistry and Molecular Biology, University of Gothenburg, 405 30 Göteborg, Sweden; Wallenberg Centre for Molecular and Translational Medicine, University of Gothenburg, 405 30 Göteborg, Sweden
| | - Ylber Sallova
- Department of Chemistry and Molecular Biology, University of Gothenburg, 405 30 Göteborg, Sweden; Wallenberg Centre for Molecular and Translational Medicine, University of Gothenburg, 405 30 Göteborg, Sweden
| | - Irena Matečko-Burmann
- Wallenberg Centre for Molecular and Translational Medicine, University of Gothenburg, 405 30 Göteborg, Sweden; Department of Psychiatry and Neurochemistry, University of Gothenburg, 405 30 Göteborg, Sweden
| | - Björn M Burmann
- Department of Chemistry and Molecular Biology, University of Gothenburg, 405 30 Göteborg, Sweden; Wallenberg Centre for Molecular and Translational Medicine, University of Gothenburg, 405 30 Göteborg, Sweden.
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4
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Nag R, Joshi S, Rathore AS, Majumder S. Profiling Enzyme Activity of l-Asparaginase II by NMR-Based Methyl Fingerprinting at Natural Abundance. J Am Chem Soc 2023; 145:10826-10838. [PMID: 37154467 DOI: 10.1021/jacs.3c02154] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
l-asparaginase II (MW 135 kDa) from E. coli is an FDA-approved protein drug used for the treatment of childhood leukemia. Despite its long history as a chemotherapeutic, the structural basis of enzyme action, in solution, remains widely contested. In this work, methyl-based 2D [1H-13C]-heteronuclear single-quantum correlation (HSQC) NMR, at natural abundance, has been used to profile the enzymatic activity of the commercially available enzyme drug. The [1H-13C]-HSQC NMR spectra of the protein reveal the role of a flexible loop segment in the activity of the enzyme, in solution. Addition of asparagine to the protein results in distinct conformational changes of the loop that could be signatures of intermediates formed in the catalytic reaction. To this end, an isothermal titration calorimetry (ITC)-based assay has been developed to measure the enzymatic reaction enthalpy, as a marker for its activity. Combining both ITC and NMR, it was shown that the disruption of the protein conformation can result in the loss of function. The scope, robustness, and validity of the loop fingerprints in relation to enzyme activity have been tested under different solution conditions. Overall, our results indicate that 2D NMR can be used reliably to gauge the structure-function of this enzyme, bypassing the need to label the protein. Such natural abundant NMR methods can be potentially extended to probe the structure-function aspects of high-molecular-weight protein therapeutics (glycosylated protein drugs, enzymes, therapeutic monoclonal antibodies, antibody-drug conjugates, and Fc-fusion proteins), where (a) flexible loops are required for their function and (b) isotope labeling may not be straightforward.
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Affiliation(s)
- Rachayita Nag
- Biophysics & Structural Genomics, Saha Institute of Nuclear Physics, Kolkata 700064, India
- Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094, India
| | - Srishti Joshi
- Department of Chemical Engineering, Indian Institute of Technology, Hauz Khas, New Delhi 110016, India
| | - Anurag Singh Rathore
- Department of Chemical Engineering, Indian Institute of Technology, Hauz Khas, New Delhi 110016, India
| | - Subhabrata Majumder
- Biophysics & Structural Genomics, Saha Institute of Nuclear Physics, Kolkata 700064, India
- Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094, India
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5
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Kleist AB, Jenjak S, Sente A, Laskowski LJ, Szpakowska M, Calkins MM, Anderson EI, McNally LM, Heukers R, Bobkov V, Peterson FC, Thomas MA, Chevigné A, Smit MJ, McCorvy JD, Babu MM, Volkman BF. Conformational selection guides β-arrestin recruitment at a biased G protein-coupled receptor. Science 2022; 377:222-228. [PMID: 35857540 PMCID: PMC9574477 DOI: 10.1126/science.abj4922] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
G protein-coupled receptors (GPCRs) recruit β-arrestins to coordinate diverse cellular processes, but the structural dynamics driving this process are poorly understood. Atypical chemokine receptors (ACKRs) are intrinsically biased GPCRs that engage β-arrestins but not G proteins, making them a model system for investigating the structural basis of β-arrestin recruitment. Here, we performed nuclear magnetic resonance (NMR) experiments on 13CH3-ε-methionine-labeled ACKR3, revealing that β-arrestin recruitment is associated with conformational exchange at key regions of the extracellular ligand-binding pocket and intracellular β-arrestin-coupling region. NMR studies of ACKR3 mutants defective in β-arrestin recruitment identified an allosteric hub in the receptor core that coordinates transitions among heterogeneously populated and selected conformational states. Our data suggest that conformational selection guides β-arrestin recruitment by tuning receptor dynamics at intracellular and extracellular regions.
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Affiliation(s)
- Andrew B Kleist
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI 53226, USA.,Medical Scientist Training Program, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Shawn Jenjak
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Andrija Sente
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK
| | - Lauren J Laskowski
- Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Martyna Szpakowska
- Immuno-Pharmacology and Interactomics, Department of Infection and Immunity, Luxembourg Institute of Health (LIH), L-4354 Esch-sur-Alzette, Luxembourg
| | - Maggie M Calkins
- Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Emilie I Anderson
- Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Lisa M McNally
- Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Raimond Heukers
- Amsterdam Institute for Molecular and Life Sciences, Division of Medicinal Chemistry, Faculty of Sciences, Vrije Universiteit, 1081 HZ Amsterdam, Netherlands
| | - Vladimir Bobkov
- Amsterdam Institute for Molecular and Life Sciences, Division of Medicinal Chemistry, Faculty of Sciences, Vrije Universiteit, 1081 HZ Amsterdam, Netherlands
| | - Francis C Peterson
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Monica A Thomas
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI 53226, USA.,Medical Scientist Training Program, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Andy Chevigné
- Immuno-Pharmacology and Interactomics, Department of Infection and Immunity, Luxembourg Institute of Health (LIH), L-4354 Esch-sur-Alzette, Luxembourg
| | - Martine J Smit
- Amsterdam Institute for Molecular and Life Sciences, Division of Medicinal Chemistry, Faculty of Sciences, Vrije Universiteit, 1081 HZ Amsterdam, Netherlands
| | - John D McCorvy
- Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - M Madan Babu
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA.,Center for Data Driven Discovery, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Brian F Volkman
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI 53226, USA
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6
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Karunanithy G, Shukla VK, Hansen DF. Methodological advancements for characterising protein side chains by NMR spectroscopy. Curr Opin Struct Biol 2021; 70:61-69. [PMID: 33989947 DOI: 10.1016/j.sbi.2021.04.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Revised: 03/31/2021] [Accepted: 04/01/2021] [Indexed: 11/18/2022]
Abstract
The surface of proteins is covered by side chains of polar amino acids that are imperative for modulating protein functionality through the formation of noncovalent intermolecular interactions. However, despite their tremendous importance, the unique structures of protein side chains require tailored approaches for investigation by nuclear magnetic resonance spectroscopy and so have traditionally been understudied compared with the protein backbone. Here, we review substantial recent methodological advancements within nuclear magnetic resonance spectroscopy to address this issue. Specifically, we consider advancements that provide new insight into methyl-bearing side chains, show the potential of using non-natural amino acids and reveal the actions of charged side chains. Combined, the new methods promise unprecedented characterisations of side chains that will further elucidate protein function.
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Affiliation(s)
- Gogulan Karunanithy
- Department of Structural and Molecular Biology, Division of Biosciences, University College London, London, WC1E 6BT, United Kingdom
| | - Vaibhav Kumar Shukla
- Department of Structural and Molecular Biology, Division of Biosciences, University College London, London, WC1E 6BT, United Kingdom
| | - D Flemming Hansen
- Department of Structural and Molecular Biology, Division of Biosciences, University College London, London, WC1E 6BT, United Kingdom.
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7
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Mizukoshi Y, Takeuchi K, Tokunaga Y, Matsuo H, Imai M, Fujisaki M, Kamoshida H, Takizawa T, Hanzawa H, Shimada I. Targeting the cryptic sites: NMR-based strategy to improve protein druggability by controlling the conformational equilibrium. SCIENCE ADVANCES 2020; 6:eabd0480. [PMID: 32998885 PMCID: PMC7527212 DOI: 10.1126/sciadv.abd0480] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Accepted: 08/06/2020] [Indexed: 06/11/2023]
Abstract
Cryptic ligand binding sites, which are not evident in the unligated structures, are beneficial in tackling with difficult but attractive drug targets, such as protein-protein interactions (PPIs). However, cryptic sites have thus far not been rationally pursued in the early stages of drug development. Here, we demonstrated by nuclear magnetic resonance that the cryptic site in Bcl-xL exists in a conformational equilibrium between the open and closed conformations under the unligated condition. While the fraction of the open conformation in the unligated wild-type Bcl-xL is estimated to be low, F143W mutation that is distal from the ligand binding site can substantially elevate the population. The F143W mutant showed a higher hit rate in a phage-display peptide screening, and the hit peptide bound to the cryptic site of the wild-type Bcl-xL. Therefore, by controlling the conformational equilibrium in the cryptic site, the opportunity to identify a PPI inhibitor could be improved.
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Affiliation(s)
| | - Koh Takeuchi
- National Institute of Advanced Industrial Science and Technology (AIST), Molecular Profiling Research Center for Drug Discovery (molprof) and Cellular and Molecular Biotechnology Research Institute, Tokyo 135-0063, Japan.
| | - Yuji Tokunaga
- National Institute of Advanced Industrial Science and Technology (AIST), Molecular Profiling Research Center for Drug Discovery (molprof) and Cellular and Molecular Biotechnology Research Institute, Tokyo 135-0063, Japan
| | - Hitomi Matsuo
- Japan Biological Informatics Consortium, Tokyo 135-0063, Japan
| | - Misaki Imai
- Japan Biological Informatics Consortium, Tokyo 135-0063, Japan
| | - Miwa Fujisaki
- Japan Biological Informatics Consortium, Tokyo 135-0063, Japan
| | | | | | | | - Ichio Shimada
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113-0033, Japan.
- RIKEN, Center for Biosystems Dynamics Research, Yokohama 230-0045, Japan
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8
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Siemons L, Uluca-Yazgi B, Pritchard RB, McCarthy S, Heise H, Hansen DF. Determining isoleucine side-chain rotamer-sampling in proteins from 13C chemical shift. Chem Commun (Camb) 2019; 55:14107-14110. [PMID: 31642826 PMCID: PMC7138115 DOI: 10.1039/c9cc06496f] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A framework is presented to derive the conformational sampling of isoleucine side chains from nuclear magnetic resonance 13C chemical shifts.
Chemical shifts are often the only nuclear magnetic resonance parameter that can be obtained for challenging macromolecular systems. Here we present a framework to derive the conformational sampling of isoleucine side chains from 13C chemical shifts and demonstrate that side-chain conformations in a low-populated folding intermediate can be determined.
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Affiliation(s)
- Lucas Siemons
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London, UKWC1E 6BT.
| | - Boran Uluca-Yazgi
- Institut für Physikalische Biologie, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany and Institute of Complex Systems, ICS-6: Structural Biochemistry and JuStruct: Jülich Center for Structural Biology, Forschungszentrum Jülich, Jülich, Germany
| | - Ruth B Pritchard
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London, UKWC1E 6BT.
| | - Stephen McCarthy
- Department of Chemistry, University College London, 20, Gordon Street, London, WC1H 0AJ, UK
| | - Henrike Heise
- Institut für Physikalische Biologie, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany and Institute of Complex Systems, ICS-6: Structural Biochemistry and JuStruct: Jülich Center for Structural Biology, Forschungszentrum Jülich, Jülich, Germany
| | - D Flemming Hansen
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London, UKWC1E 6BT.
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9
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Weininger U, Modig K, Ishida H, Vogel HJ, Akke M. Rotamer Jumps, Proton Exchange, and Amine Inversion Dynamics of Dimethylated Lysine Residues in Proteins Resolved by pH-Dependent 1H and 13C NMR Relaxation Dispersion. J Phys Chem B 2019; 123:9742-9750. [PMID: 31580078 DOI: 10.1021/acs.jpcb.9b06408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Post-translational methylation of lysine side chains is of great importance for protein regulation, including epigenetic control. Here, we present specific 13CHD2 labeling of dimethylated lysines as a sensitive probe of the structure, interactions, and dynamics of these groups, and outline a theoretical and experimental framework for analyzing their conformational dynamics using 1H and 13C CPMG relaxation dispersion experiments. Dimethylated lysine side chains in calcium-loaded calmodulin show a marked pH dependence of their Carr-Purcell-Meiboom-Gill (CPMG) dispersion profiles, indicating complex exchange behavior. Combined analysis of 1H and 13C CPMG relaxation dispersions requires consideration of 12-state correlated exchange of the two methyl groups due to circular three-state rotamer jumps around the Cε-Nζ axis combined with proton exchange and amine inversion. Taking into account a number of fundamental constraints, the exchange model can be reduced to include only three fitted parameters, namely, the geometric average of the rotamer-jump rate constants, the rate constant of deprotonation of Nζ, and the chemical shift difference between the trans and gauge positions of the 13C or 1H nuclei. The pH dependence indicates that protonation of the end group dramatically slows down rotamer exchange for some lysine residues, whereas deprotonation leads to rapid amine inversion coupled with rotamer scrambling. The observed variation among residues in their exchange behavior appears to depend on the structural environment of the side chain. Understanding this type of exchange process is critical to correctly interpreting NMR spectra of methylated lysine side chains. The exchange model presented here forms the basis for studying the structure and dynamics of epigenetically modified lysine side chains and perturbations caused by changes in pH or interactions with target proteins.
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Affiliation(s)
- Ulrich Weininger
- Biophysical Chemistry, Center for Molecular Protein Science, Department of Chemistry , Lund University , P.O. Box 124, SE-221 00 Lund , Sweden
| | - Kristofer Modig
- Biophysical Chemistry, Center for Molecular Protein Science, Department of Chemistry , Lund University , P.O. Box 124, SE-221 00 Lund , Sweden
| | - Hiroaki Ishida
- Department of Biological Sciences, Biochemistry Research Group , University of Calgary , 2500 University Drive NW , Calgary , Alberta , T2N 1N4 Canada
| | - Hans J Vogel
- Department of Biological Sciences, Biochemistry Research Group , University of Calgary , 2500 University Drive NW , Calgary , Alberta , T2N 1N4 Canada
| | - Mikael Akke
- Biophysical Chemistry, Center for Molecular Protein Science, Department of Chemistry , Lund University , P.O. Box 124, SE-221 00 Lund , Sweden
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10
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DeRose EF, Kirby TW, Mueller GA, Beard WA, Wilson SH, London RE. Transitions in DNA polymerase β μs-ms dynamics related to substrate binding and catalysis. Nucleic Acids Res 2019; 46:7309-7322. [PMID: 29917149 PMCID: PMC6101544 DOI: 10.1093/nar/gky503] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Accepted: 05/24/2018] [Indexed: 11/12/2022] Open
Abstract
DNA polymerase β (pol β) plays a central role in the DNA base excision repair pathway and also serves as an important model polymerase. Dynamic characterization of pol β from methyl-TROSY 13C-1H multiple quantum CPMG relaxation dispersion experiments of Ile and Met sidechains and previous backbone relaxation dispersion measurements, reveals transitions in μs-ms dynamics in response to highly variable substrates. Recognition of a 1-nt-gapped DNA substrate is accompanied by significant backbone and sidechain motion in the lyase domain and the DNA binding subdomain of the polymerase domain, that may help to facilitate binding of the apoenzyme to the segments of the DNA upstream and downstream from the gap. Backbone μs-ms motion largely disappears after formation of the pol β-DNA complex, giving rise to an increase in uncoupled μs-ms sidechain motion throughout the enzyme. Formation of an abortive ternary complex using a non-hydrolyzable dNTP results in sidechain motions that fit to a single exchange process localized to the catalytic subdomain, suggesting that this motion may play a role in catalysis.
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Affiliation(s)
- Eugene F DeRose
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Thomas W Kirby
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Geoffrey A Mueller
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - William A Beard
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Samuel H Wilson
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Robert E London
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
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11
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Cao H, Wang L, Cao M, Ye T, Sun Y. Computational insights on agonist and antagonist mechanisms of estrogen receptor α induced by bisphenol A analogues. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2019; 248:536-545. [PMID: 30831350 DOI: 10.1016/j.envpol.2019.02.058] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Revised: 02/09/2019] [Accepted: 02/18/2019] [Indexed: 06/09/2023]
Abstract
Structural analogues of bisphenol A (BPA) have become widely used as alternatives in BPA-free products. Most toxicological investigations have focused on the estrogenic activities of these analogues, which have been considered as potential environmental estrogens. However, recent studies revealed that certain BPA analogues could dramatically inhibit the proliferation of breast cancer cells, and exhibited strong anti-estrogenic effects compared with the antagonist 4-hydroxytamoxifen (OHT). Thus, we adopted computational models combining molecular dynamics simulations and binding free energy calculations to explore the underlying molecular basis of BPA analogues binding to estrogen receptor α (ERα). We also evaluated ligand-induced structural rearrangements of ERα at the atomic level. Conformational analyses showed that induced-fit H-bonding recognition by Thr347 was an important factor distinguishing antagonist from agonist BPA analogues. Moreover, antagonists of BPA analogues could indirectly induce the structural reposition of key helix 12 and produce an antagonistic conformation of ERα. Compared with OHT, the binding affinity of BPA analogues is stronger for antagonists than agonists. Taken together, we therefore propose computational indicators for screening of anti-estrogenic activities of BPA analogues, which may be beneficial for predicting the estrogenic or anti-estrogenic effects of BPA alternatives.
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Affiliation(s)
- Huiming Cao
- Hubei Key Laboratory of Environmental and Health Effects of Persistent Toxic Substances, Jianghan University, Wuhan, 430056, China; Institute of Environment and Health, Jianghan University, Wuhan, 430056, China
| | - Ling Wang
- Hubei Key Laboratory of Environmental and Health Effects of Persistent Toxic Substances, Jianghan University, Wuhan, 430056, China; Institute of Environment and Health, Jianghan University, Wuhan, 430056, China
| | - Mengxi Cao
- Hubei Key Laboratory of Environmental and Health Effects of Persistent Toxic Substances, Jianghan University, Wuhan, 430056, China; Institute of Environment and Health, Jianghan University, Wuhan, 430056, China
| | - Tong Ye
- Hubei Key Laboratory of Environmental and Health Effects of Persistent Toxic Substances, Jianghan University, Wuhan, 430056, China; Institute of Environment and Health, Jianghan University, Wuhan, 430056, China
| | - Yuzhen Sun
- Hubei Key Laboratory of Environmental and Health Effects of Persistent Toxic Substances, Jianghan University, Wuhan, 430056, China; Institute of Environment and Health, Jianghan University, Wuhan, 430056, China.
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12
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Peixoto PDS, Trivelli X, André C, Moreau A, Delaplace G. Formation of β-Lactoglobulin Aggregates from Quite, Unfolded Conformations upon Heat Activation. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:446-452. [PMID: 30565468 DOI: 10.1021/acs.langmuir.8b03459] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
In presence of calcium ions, β-lactoglobulin (BLG) unfolds and subsequently aggregates after heating. This process has important pharmaceutical and agroalimentary applications. Nowadays, the molecular mechanism of unfolding and BLG aggregation, and the role of calcium in the mechanism, is poorly understood. Actually, in most studies, data have been acquired at room temperature, after heating and after aggregation, which makes it difficult to establish a clear causal-temporal relation between calcium binding, heat, and aggregation. Thus, the goal of the present study is to get accurate, nanoscale data about the molecular events leading to BLG unfolding and calcium-dependent aggregation. The molecular transformation of BLG during heating has been investigated, using the NMR pulse field gradient technique, operating in a high field (900 MHz). Thanks to this technique, the molecular conformation of newly formed unfolded BLG molecules can be distinguished in a large pool of native ones. The present work shows that BLG at neutral pH at 65 °C displays fast, cooperative-like unfolding, in which no long-lived intermediary state (as a molten globule one) is detected, before aggregation. These data also indicate that calcium ions bind unfolded BLG in specific sites which might be a necessary feature to form the aggregate. Finally, these data also provide an NMR-based methodology to monitor the rate of protein unfolding using NMR.
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Affiliation(s)
- Paulo D S Peixoto
- Univ. Lille, UMR 8207-UMET-Unité Matériaux et Transformations , 59000 Lille , France
- INRA , 59000 Lille , France
| | - Xavier Trivelli
- Université de Lille, CNRS, UMR 8576-UGSF-Unité de Glycobiologie Structurale et Fonctionnelle , 59655 Lille , France
| | - Christophe André
- Univ. Lille, UMR 8207-UMET-Unité Matériaux et Transformations , 59000 Lille , France
- INRA , 59000 Lille , France
- UC Lille, HEI, Laboratoire de Génie des Procédés , 59046 Lille , France
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13
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Kleist AB, Peterson F, Tyler RC, Gustavsson M, Handel TM, Volkman BF. Solution NMR spectroscopy of GPCRs: Residue-specific labeling strategies with a focus on 13C-methyl methionine labeling of the atypical chemokine receptor ACKR3. Methods Cell Biol 2018; 149:259-288. [PMID: 30616824 DOI: 10.1016/bs.mcb.2018.09.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The past decade has witnessed remarkable progress in the determination of G protein-coupled receptor (GPCR) structures, profoundly expanding our understanding of how GPCRs recognize ligands, become activated, and interact with intracellular signaling components. In recent years, numerous studies have used solution nuclear magnetic resonance (NMR) spectroscopy to investigate GPCRs, providing fundamental insights into GPCR conformational changes, allostery, dynamics, and other facets of GPCR function are challenging to study using other structural techniques. Despite these advantages, NMR-based studies of GPCRs are few relative to the number of published structures, due in part to the challenges and limitations of NMR for the characterization of large membrane proteins. Several studies have circumvented these challenges using a variety of isotopic labeling strategies, including side chain derivatization and metabolic incorporation of NMR-active nuclei. In this chapter, we provide an overview of different isotopic labeling strategies and describe an in-depth protocol for the expression, purification, and NMR studies of the chemokine GPCR atypical chemokine receptor 3 (ACKR3) via 13CH3-methionine incorporation. The goal of this chapter is to provide a resource to the GPCR community for those interested in pursuing NMR studies of GPCRs.
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Affiliation(s)
- Andrew B Kleist
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Francis Peterson
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Robert C Tyler
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Martin Gustavsson
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, CA, United States
| | - Tracy M Handel
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, CA, United States
| | - Brian F Volkman
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI, United States.
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14
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GPCR drug discovery: integrating solution NMR data with crystal and cryo-EM structures. Nat Rev Drug Discov 2018; 18:59-82. [PMID: 30410121 DOI: 10.1038/nrd.2018.180] [Citation(s) in RCA: 162] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The 826 G protein-coupled receptors (GPCRs) in the human proteome regulate key physiological processes and thus have long been attractive drug targets. With the crystal structures of more than 50 different human GPCRs determined over the past decade, an initial platform for structure-based rational design has been established for drugs that target GPCRs, which is currently being augmented with cryo-electron microscopy (cryo-EM) structures of higher-order GPCR complexes. Nuclear magnetic resonance (NMR) spectroscopy in solution is one of the key approaches for expanding this platform with dynamic features, which can be accessed at physiological temperature and with minimal modification of the wild-type GPCR covalent structures. Here, we review strategies for the use of advanced biochemistry and NMR techniques with GPCRs, survey projects in which crystal or cryo-EM structures have been complemented with NMR investigations and discuss the impact of this integrative approach on GPCR biology and drug discovery.
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15
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Nerli S, McShan AC, Sgourakis NG. Chemical shift-based methods in NMR structure determination. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2018; 106-107:1-25. [PMID: 31047599 PMCID: PMC6788782 DOI: 10.1016/j.pnmrs.2018.03.002] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Revised: 03/09/2018] [Accepted: 03/09/2018] [Indexed: 05/08/2023]
Abstract
Chemical shifts are highly sensitive probes harnessed by NMR spectroscopists and structural biologists as conformational parameters to characterize a range of biological molecules. Traditionally, assignment of chemical shifts has been a labor-intensive process requiring numerous samples and a suite of multidimensional experiments. Over the past two decades, the development of complementary computational approaches has bolstered the analysis, interpretation and utilization of chemical shifts for elucidation of high resolution protein and nucleic acid structures. Here, we review the development and application of chemical shift-based methods for structure determination with a focus on ab initio fragment assembly, comparative modeling, oligomeric systems, and automated assignment methods. Throughout our discussion, we point out practical uses, as well as advantages and caveats, of using chemical shifts in structure modeling. We additionally highlight (i) hybrid methods that employ chemical shifts with other types of NMR restraints (residual dipolar couplings, paramagnetic relaxation enhancements and pseudocontact shifts) that allow for improved accuracy and resolution of generated 3D structures, (ii) the utilization of chemical shifts to model the structures of sparsely populated excited states, and (iii) modeling of sidechain conformations. Finally, we briefly discuss the advantages of contemporary methods that employ sparse NMR data recorded using site-specific isotope labeling schemes for chemical shift-driven structure determination of larger molecules. With this review, we aim to emphasize the accessibility and versatility of chemical shifts for structure determination of challenging biological systems, and to point out emerging areas of development that lead us towards the next generation of tools.
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Affiliation(s)
- Santrupti Nerli
- Department of Chemistry and Biochemistry, University of California Santa Cruz, Santa Cruz, CA 95064, United States; Department of Computer Science, University of California Santa Cruz, Santa Cruz, CA 95064, United States
| | - Andrew C McShan
- Department of Chemistry and Biochemistry, University of California Santa Cruz, Santa Cruz, CA 95064, United States
| | - Nikolaos G Sgourakis
- Department of Chemistry and Biochemistry, University of California Santa Cruz, Santa Cruz, CA 95064, United States.
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16
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Phosphorylation-induced conformation of β 2-adrenoceptor related to arrestin recruitment revealed by NMR. Nat Commun 2018; 9:194. [PMID: 29335412 PMCID: PMC5768704 DOI: 10.1038/s41467-017-02632-8] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2017] [Accepted: 12/15/2017] [Indexed: 02/07/2023] Open
Abstract
The C-terminal region of G-protein-coupled receptors (GPCRs), stimulated by agonist binding, is phosphorylated by GPCR kinases, and the phosphorylated GPCRs bind to arrestin, leading to the cellular responses. To understand the mechanism underlying the formation of the phosphorylated GPCR-arrestin complex, we performed NMR analyses of the phosphorylated β2-adrenoceptor (β2AR) and the phosphorylated β2AR–β-arrestin 1 complex, in the lipid bilayers of nanodisc. Here we show that the phosphorylated C-terminal region adheres to either the intracellular side of the transmembrane region or lipids, and that the phosphorylation of the C-terminal region allosterically alters the conformation around M2155.54 and M2796.41, located on transemembrane helices 5 and 6, respectively. In addition, we found that the conformation induced by the phosphorylation is similar to that corresponding to the β-arrestin-bound state. The phosphorylation-induced structures revealed in this study propose a conserved structural motif of GPCRs that enables β-arrestin to recognize dozens of GPCRs. Upon stimulation by agonist binding, the C-terminal regions of G-protein-coupled receptors (GPCRs) become phosphorylated by GPCR kinases, and phosphorylated GPCRs bind arrestin. Here the authors give structural insights into the phosphorylation induced conformational changes in GPCRs by performing NMR studies with the β2-adrenoceptor.
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17
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Beck Erlach M, Koehler J, Crusca E, Munte CE, Kainosho M, Kremer W, Kalbitzer HR. Pressure dependence of side chain 13C chemical shifts in model peptides Ac-Gly-Gly-Xxx-Ala-NH 2. JOURNAL OF BIOMOLECULAR NMR 2017; 69:53-67. [PMID: 28913741 DOI: 10.1007/s10858-017-0134-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Accepted: 09/05/2017] [Indexed: 06/07/2023]
Abstract
For evaluating the pressure responses of folded as well as intrinsically unfolded proteins detectable by NMR spectroscopy the availability of data from well-defined model systems is indispensable. In this work we report the pressure dependence of 13C chemical shifts of the side chain atoms in the protected tetrapeptides Ac-Gly-Gly-Xxx-Ala-NH2 (Xxx, one of the 20 canonical amino acids). Contrary to expectation the chemical shifts of a number of nuclei have a nonlinear dependence on pressure in the range from 0.1 to 200 MPa. The size of the polynomial pressure coefficients B 1 and B 2 is dependent on the type of atom and amino acid studied. For HN, N and Cα the first order pressure coefficient B 1 is also correlated to the chemical shift at atmospheric pressure. The first and second order pressure coefficients of a given type of carbon atom show significant linear correlations suggesting that the NMR observable pressure effects in the different amino acids have at least partly the same physical cause. In line with this observation the magnitude of the second order coefficients of nuclei being direct neighbors in the chemical structure also are weakly correlated. The downfield shifts of the methyl resonances suggest that gauche conformers of the side chains are not preferred with pressure. The valine and leucine methyl groups in the model peptides were assigned using stereospecifically 13C enriched amino acids with the pro-R carbons downfield shifted relative to the pro-S carbons.
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Affiliation(s)
- Markus Beck Erlach
- Institute of Biophysics and Physical Biochemistry and Centre of Magnetic Resonance in Chemistry and Biomedicine, University of Regensburg, 93040, Regensburg, Germany
| | - Joerg Koehler
- Institute of Biophysics and Physical Biochemistry and Centre of Magnetic Resonance in Chemistry and Biomedicine, University of Regensburg, 93040, Regensburg, Germany
| | - Edson Crusca
- Institute of Chemistry, São Paulo State University (UNESP), Araraquara, 14800-060, Brazil
| | - Claudia E Munte
- Institute of Biophysics and Physical Biochemistry and Centre of Magnetic Resonance in Chemistry and Biomedicine, University of Regensburg, 93040, Regensburg, Germany
- Physics Institute of São Carlos, University of São Paulo, São Carlos, 13566-590, Brazil
| | - Masatsune Kainosho
- Graduate School of Science and Technology, Tokyo Metropolitan University, 1-1 Minami-ohsawa, Hachioji, Tokyo, 192-0397, Japan
| | - Werner Kremer
- Institute of Biophysics and Physical Biochemistry and Centre of Magnetic Resonance in Chemistry and Biomedicine, University of Regensburg, 93040, Regensburg, Germany
| | - Hans Robert Kalbitzer
- Institute of Biophysics and Physical Biochemistry and Centre of Magnetic Resonance in Chemistry and Biomedicine, University of Regensburg, 93040, Regensburg, Germany.
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18
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Ziarek JJ, Baptista D, Wagner G. Recent developments in solution nuclear magnetic resonance (NMR)-based molecular biology. J Mol Med (Berl) 2017. [PMID: 28643003 DOI: 10.1007/s00109-017-1560-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Visualizing post-translational modifications, conformations, and interaction surfaces of protein structures at atomic resolution underpins the development of novel therapeutics to combat disease. As computational resources expand, in silico calculations coupled with experimentally derived structures and functional assays have led to an explosion in structure-based drug design (SBDD) with several compounds in clinical trials. It is increasingly clear that "hidden" transition-state structures along activation trajectories can be harnessed to develop novel classes of allosteric inhibitors. The goal of this mini-review is to empower the clinical researcher with a general knowledge of the strengths and weaknesses of nuclear magnetic resonance (NMR) spectroscopy in molecular medicine. Although NMR can determine protein structures at atomic resolution, its unrivaled strength lies in sensing subtle changes in a nuclei's chemical environment as a result of intrinsic conformational dynamics, solution conditions, and binding interactions. These can be recorded at atomic resolution, without explicit structure determination, and then incorporated with static structures or molecular dynamics simulations to produce a complete biological picture.
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Affiliation(s)
- Joshua J Ziarek
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, 240 Longwood Ave, Boston, MA, 02115, USA
| | - Diego Baptista
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, 240 Longwood Ave, Boston, MA, 02115, USA
| | - Gerhard Wagner
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, 240 Longwood Ave, Boston, MA, 02115, USA.
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19
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Li X, Neumann MA, van de Streek J. The application of tailor-made force fields and molecular dynamics for NMR crystallography: a case study of free base cocaine. IUCRJ 2017; 4:175-184. [PMID: 28250956 PMCID: PMC5330528 DOI: 10.1107/s2052252517001415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Accepted: 01/27/2017] [Indexed: 05/04/2023]
Abstract
Motional averaging has been proven to be significant in predicting the chemical shifts in ab initio solid-state NMR calculations, and the applicability of motional averaging with molecular dynamics has been shown to depend on the accuracy of the molecular mechanical force field. The performance of a fully automatically generated tailor-made force field (TMFF) for the dynamic aspects of NMR crystallography is evaluated and compared with existing benchmarks, including static dispersion-corrected density functional theory calculations and the COMPASS force field. The crystal structure of free base cocaine is used as an example. The results reveal that, even though the TMFF outperforms the COMPASS force field for representing the energies and conformations of predicted structures, it does not give significant improvement in the accuracy of NMR calculations. Further studies should direct more attention to anisotropic chemical shifts and development of the method of solid-state NMR calculations.
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Affiliation(s)
- Xiaozhou Li
- Department of Pharmacy, University of Copenhagen, Universitetsparken 2, Copenhagen DK-2100, Denmark
| | - Marcus A. Neumann
- Avant-garde Materials Simulation Deutschland GmbH, Rosa-Luxemberg-Strasse 14, Freiburg D-79100, Germany
| | - Jacco van de Streek
- Department of Pharmacy, University of Copenhagen, Universitetsparken 2, Copenhagen DK-2100, Denmark
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20
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Toyama Y, Kano H, Mase Y, Yokogawa M, Osawa M, Shimada I. Dynamic regulation of GDP binding to G proteins revealed by magnetic field-dependent NMR relaxation analyses. Nat Commun 2017; 8:14523. [PMID: 28223697 PMCID: PMC5322562 DOI: 10.1038/ncomms14523] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Accepted: 01/10/2017] [Indexed: 11/30/2022] Open
Abstract
Heterotrimeric guanine-nucleotide-binding proteins (G proteins) serve as molecular switches in signalling pathways, by coupling the activation of cell surface receptors to intracellular responses. Mutations in the G protein α-subunit (Gα) that accelerate guanosine diphosphate (GDP) dissociation cause hyperactivation of the downstream effector proteins, leading to oncogenesis. However, the structural mechanism of the accelerated GDP dissociation has remained unclear. Here, we use magnetic field-dependent nuclear magnetic resonance relaxation analyses to investigate the structural and dynamic properties of GDP bound Gα on a microsecond timescale. We show that Gα rapidly exchanges between a ground-state conformation, which tightly binds to GDP and an excited conformation with reduced GDP affinity. The oncogenic D150N mutation accelerates GDP dissociation by shifting the equilibrium towards the excited conformation. Heterotrimeric guanine-nucleotide-binding proteins (G proteins) act as molecular switches. Here the authors use NMR relaxation analyses, which reveal the dynamics of G protein alpha subunit binding to GDP on a microsecond timescale.
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Affiliation(s)
- Yuki Toyama
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.,Japan Biological Informatics Consortium (JBiC), Aomi, Koto-ku, Tokyo 135-0064, Japan
| | - Hanaho Kano
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Yoko Mase
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Mariko Yokogawa
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Masanori Osawa
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Ichio Shimada
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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21
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Sinha K, Sangani SS, Kehr AD, Rule GS, Jen-Jacobson L. Metal Ion Binding at the Catalytic Site Induces Widely Distributed Changes in a Sequence Specific Protein-DNA Complex. Biochemistry 2016; 55:6115-6132. [PMID: 27786446 PMCID: PMC5402698 DOI: 10.1021/acs.biochem.6b00919] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
![]()
Metal
ion cofactors can alter the energetics and specificity of
sequence specific protein–DNA interactions, but it is unknown
if the underlying effects on structure and dynamics are local or dispersed
throughout the protein–DNA complex. This work uses EcoRV endonuclease
as a model, and catalytically inactive lanthanide ions, which replace
the Mg2+ cofactor. Nuclear magnetic resonance (NMR) titrations
indicate that four Lu3+ or two La3+ cations
bind, and two new crystal structures confirm that Lu3+ binding
is confined to the active sites. NMR spectra show that the metal-free
EcoRV complex with cognate (GATATC) DNA is structurally distinct from
the nonspecific complex, and that metal ion binding sites are not
assembled in the nonspecific complex. NMR chemical shift perturbations
were determined for 1H–15N amide resonances,
for 1H–13C Ile-δ-CH3 resonances, and for stereospecifically assigned Leu-δ-CH3 and Val-γ-CH3 resonances. Many chemical
shifts throughout the cognate complex are unperturbed, so metal binding
does not induce major conformational changes. However, some large
perturbations of amide and side chain methyl resonances occur as far
as 34 Å from the metal ions. Concerted changes in specific residues
imply that local effects of metal binding are propagated via a β-sheet
and an α-helix. Both amide and methyl resonance perturbations
indicate changes in the interface between subunits of the EcoRV homodimer.
Bound metal ions also affect amide hydrogen exchange rates for distant
residues, including a distant subdomain that contacts DNA phosphates
and promotes DNA bending, showing that metal ions in the active sites,
which relieve electrostatic repulsion between protein and DNA, cause
changes in slow dynamics throughout the complex.
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Affiliation(s)
- Kaustubh Sinha
- Department of Biological Sciences, University of Pittsburgh , Pittsburgh, Pennsylvania 15260, United States.,Department of Biological Sciences, Carnegie Mellon University , Pittsburgh, Pennsylvania 15213, United States
| | - Sahil S Sangani
- Department of Biological Sciences, Carnegie Mellon University , Pittsburgh, Pennsylvania 15213, United States
| | - Andrew D Kehr
- Department of Biological Sciences, Carnegie Mellon University , Pittsburgh, Pennsylvania 15213, United States
| | - Gordon S Rule
- Department of Biological Sciences, Carnegie Mellon University , Pittsburgh, Pennsylvania 15213, United States
| | - Linda Jen-Jacobson
- Department of Biological Sciences, University of Pittsburgh , Pittsburgh, Pennsylvania 15260, United States
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22
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Abstract
Nuclear magnetic resonance (NMR) spectroscopy provides a unique toolbox of experimental probes for studying dynamic processes on a wide range of timescales, ranging from picoseconds to milliseconds and beyond. Along with NMR hardware developments, recent methodological advancements have enabled the characterization of allosteric proteins at unprecedented detail, revealing intriguing aspects of allosteric mechanisms and increasing the proportion of the conformational ensemble that can be observed by experiment. Here, we present an overview of NMR spectroscopic methods for characterizing equilibrium fluctuations in free and bound states of allosteric proteins that have been most influential in the field. By combining NMR experimental approaches with molecular simulations, atomistic-level descriptions of the mechanisms by which allosteric phenomena take place are now within reach.
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Affiliation(s)
- Sarina Grutsch
- Institute of Organic Chemistry, Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innsbruck, Austria
| | - Sven Brüschweiler
- Department of Computational & Structural Biology, Max F. Perutz Laboratories, Campus Vienna Biocenter 5, Vienna, Austria
| | - Martin Tollinger
- Institute of Organic Chemistry, Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innsbruck, Austria
- * E-mail:
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23
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Toyama Y, Osawa M, Yokogawa M, Shimada I. NMR Method for Characterizing Microsecond-to-Millisecond Chemical Exchanges Utilizing Differential Multiple-Quantum Relaxation in High Molecular Weight Proteins. J Am Chem Soc 2016; 138:2302-11. [PMID: 26855064 DOI: 10.1021/jacs.5b12954] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Chemical exchange processes of proteins on the order of microseconds (μs) to milliseconds (ms) play critical roles in biological functions. Developments in methyl-transverse relaxation optimized spectroscopy (methyl-TROSY), which observes the slowly relaxing multiple quantum (MQ) coherences, have enabled the studies of biologically important large proteins. However, the analyses of μs to ms chemical exchange processes based on the methyl-TROSY principle are still challenging, because the interpretation of the chemical exchange contributions to the MQ relaxation profiles is complicated, as significant chemical shift differences occur in both (1)H and (13)C nuclei. Here, we report a new methyl-based NMR method for characterizing chemical exchanges, utilizing differential MQ relaxation rates and a heteronuclear double resonance pulse technique. The method enables quantitative evaluations of the chemical exchange processes, in which significant chemical shift differences exist in both the (1)H and (13)C nuclei. The versatility of the method is demonstrated with the application to KirBac1.1, with an apparent molecular mass of 200 kDa.
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Affiliation(s)
- Yuki Toyama
- Graduate School of Pharmaceutical Sciences, The University of Tokyo , Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.,Japan Biological Informatics Consortium (JBIC) , Aomi, Koto-ku, Tokyo 135-0064, Japan
| | - Masanori Osawa
- Graduate School of Pharmaceutical Sciences, The University of Tokyo , Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Mariko Yokogawa
- Graduate School of Pharmaceutical Sciences, The University of Tokyo , Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Ichio Shimada
- Graduate School of Pharmaceutical Sciences, The University of Tokyo , Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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24
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Ruggiero MT, Gooch J, Zubieta J, Korter TM. Evaluation of Range-Corrected Density Functionals for the Simulation of Pyridinium-Containing Molecular Crystals. J Phys Chem A 2016; 120:939-47. [PMID: 26814572 DOI: 10.1021/acs.jpca.5b11458] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Michael T. Ruggiero
- Department of Chemistry, Syracuse University, 1-014 Center
for Science and Technology, Syracuse, New York 13244-4100, United States
| | - Jonathan Gooch
- Department of Chemistry, Syracuse University, 1-014 Center
for Science and Technology, Syracuse, New York 13244-4100, United States
| | - Jon Zubieta
- Department of Chemistry, Syracuse University, 1-014 Center
for Science and Technology, Syracuse, New York 13244-4100, United States
| | - Timothy M. Korter
- Department of Chemistry, Syracuse University, 1-014 Center
for Science and Technology, Syracuse, New York 13244-4100, United States
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25
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Kulminskaya N, Vasa SK, Giller K, Becker S, Kwan A, Sunde M, Linser R. Access to side-chain carbon information in deuterated solids under fast MAS through non-rotor-synchronized mixing. Chem Commun (Camb) 2016; 52:268-71. [DOI: 10.1039/c5cc07345f] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
MOCCA provides comprehensive solid-state NMR side chain carbon correlations despite perdeuteration and fast sample rotation, thereby inducing minimal power dissipation.
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Affiliation(s)
- Natalia Kulminskaya
- Max-Planck Institute for Biophysical Chemistry
- Department NMR-Based Structural Biology
- 37077 Göttingen
- Germany
| | - Suresh Kumar Vasa
- Max-Planck Institute for Biophysical Chemistry
- Department NMR-Based Structural Biology
- 37077 Göttingen
- Germany
| | - Karin Giller
- Max-Planck Institute for Biophysical Chemistry
- Department NMR-Based Structural Biology
- 37077 Göttingen
- Germany
| | - Stefan Becker
- Max-Planck Institute for Biophysical Chemistry
- Department NMR-Based Structural Biology
- 37077 Göttingen
- Germany
| | - Ann Kwan
- School of Medical Sciences and School of Molecular Bioscience
- University of Sydney
- Sydney
- Australia
| | - Margaret Sunde
- School of Medical Sciences and School of Molecular Bioscience
- University of Sydney
- Sydney
- Australia
| | - Rasmus Linser
- Max-Planck Institute for Biophysical Chemistry
- Department NMR-Based Structural Biology
- 37077 Göttingen
- Germany
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26
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Li F, Grishaev A, Ying J, Bax A. Side Chain Conformational Distributions of a Small Protein Derived from Model-Free Analysis of a Large Set of Residual Dipolar Couplings. J Am Chem Soc 2015; 137:14798-811. [PMID: 26523828 PMCID: PMC4665082 DOI: 10.1021/jacs.5b10072] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
![]()
Accurate
quantitative measurement of structural dispersion in proteins
remains a prime challenge to both X-ray crystallography and NMR spectroscopy.
Here we use a model-free approach based on measurement of many residual
dipolar couplings (RDCs) in differentially orienting aqueous liquid
crystalline solutions to obtain the side chain χ1 distribution sampled by each residue in solution. Applied to the
small well-ordered model protein GB3, our approach reveals that the
RDC data are compatible with a single narrow distribution of side
chain χ1 angles for only about 40% of the residues.
For more than half of the residues, populations greater than 10% for
a second rotamer are observed, and four residues require sampling
of three rotameric states to fit the RDC data. In virtually all cases,
sampled χ1 values are found to center closely around
ideal g–, g+ and t rotameric angles, even though no rotamer
restraint is used when deriving the sampled angles. The root-mean-square
difference between experimental 3JHαHβ couplings and those predicted by the Haasnoot-parametrized, motion-adjusted
Karplus equation reduces from 2.05 to 0.75 Hz when using the new rotamer
analysis instead of the 1.1-Å X-ray structure as input for the
dihedral angles. A comparison between observed and predicted 3JHαHβ values suggests that the root-mean-square
amplitude of χ1 angle fluctuations within a given
rotamer well is ca. 20°. The quantitatively defined side chain
rotamer equilibria obtained from our study set new benchmarks for
evaluating improved molecular dynamics force fields, and also will
enable further development of quantitative relations between side
chain chemical shift and structure.
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Affiliation(s)
- Fang Li
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health , Bethesda, Maryland 20892, United States
| | - Alexander Grishaev
- National Institute of Standards and Technology , Institute for Bioscience and Biotechnology Research, 9600 Gudelsky Drive, Rockville, Maryland 20850, United States
| | - Jinfa Ying
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health , Bethesda, Maryland 20892, United States
| | - Ad Bax
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health , Bethesda, Maryland 20892, United States
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27
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Methyl-specific isotopic labeling: a molecular tool box for solution NMR studies of large proteins. Curr Opin Struct Biol 2015; 32:113-22. [DOI: 10.1016/j.sbi.2015.03.009] [Citation(s) in RCA: 130] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2014] [Revised: 03/02/2015] [Accepted: 03/23/2015] [Indexed: 11/23/2022]
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28
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Caballero D, Smith WW, O'Hern CS, Regan L. Equilibrium transitions between side-chain conformations in leucine and isoleucine. Proteins 2015; 83:1488-99. [PMID: 26018846 DOI: 10.1002/prot.24837] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Revised: 04/30/2015] [Accepted: 05/20/2015] [Indexed: 12/12/2022]
Abstract
Despite recent improvements in computational methods for protein design, we still lack a quantitative, predictive understanding of the intrinsic probabilities for amino acids to adopt particular side-chain conformations. Surprisingly, this question has remained unsettled for many years, in part because of inconsistent results from different experimental approaches. To explicitly determine the relative populations of different side-chain dihedral angles, we performed all-atom hard-sphere Langevin Dynamics simulations of leucine (Leu) and isoleucine (Ile) dipeptide mimetics with stereo-chemical constraints and repulsive-only steric interactions between non-bonded atoms. We determine the relative populations of the different χ(1) and χ(2) dihedral angle combinations as a function of the backbone dihedral angles ϕ and ψ. We also propose, and test, a mechanism for inter-conversion between the different side-chain conformations. Specifically, we discover that some of the transitions between side-chain dihedral angle combinations are very frequent, whereas others are orders of magnitude less frequent, because they require rare coordinated motions to avoid steric clashes. For example, to transition between different values of χ(2), the Leu side-chain bond angles κ(1) and κ(2) must increase, whereas to transition in χ(1), the Ile bond angles λ(1) and λ(2) must increase. These results emphasize the importance of computational approaches in stimulating further experimental studies of the conformations of side-chains in proteins. Moreover, our studies emphasize the power of simple steric models to inform our understanding of protein structure, dynamics, and design.
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Affiliation(s)
- Diego Caballero
- Department of Physics, Yale University, New Haven, Connecticut.,Integrated Graduate Program in Physical and Engineering Biology, Yale University, New Haven, Connecticut
| | - W Wendell Smith
- Department of Physics, Yale University, New Haven, Connecticut
| | - Corey S O'Hern
- Department of Physics, Yale University, New Haven, Connecticut.,Integrated Graduate Program in Physical and Engineering Biology, Yale University, New Haven, Connecticut.,Department of Mechanical Engineering & Materials Science, Yale University, New Haven, Connecticut.,Department of Applied Physics, Yale University, New Haven, Connecticut
| | - Lynne Regan
- Integrated Graduate Program in Physical and Engineering Biology, Yale University, New Haven, Connecticut.,Department of Molecular Biophysics & Biochemistry, Yale University, New Haven, Connecticut.,Department of Chemistry, Yale University, New Haven, Connecticut
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29
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Dynamic multidrug recognition by multidrug transcriptional repressor LmrR. Sci Rep 2014; 4:6922. [PMID: 25403615 PMCID: PMC4235314 DOI: 10.1038/srep06922] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Accepted: 10/16/2014] [Indexed: 02/06/2023] Open
Abstract
LmrR is a multidrug transcriptional repressor that controls the expression of a major multidrug transporter, LmrCD, in Lactococcus lactis. However, the molecular mechanism by which LmrR binds to structurally unrelated compounds and is released from the promoter region remains largely unknown. Here, we structurally and dynamically characterized LmrR in the apo, compound-bound and promoter-bound states. The compound-binding site of LmrR exhibits ps–μs dynamics in the apo state, and compound ligation shifts the preexisting conformational equilibrium to varying extents to achieve multidrug recognition. Meanwhile, the compound binding induces redistribution of ps–ns dynamics to the allosteric sites, which entropically favors the high-affinity recognition. Furthermore, the reciprocal compound/promoter binding by LmrR is achieved by the incompatible conformational ensembles between the compound- and promoter-bound states. Collectively, the data show how LmrR can dynamically exert its functions through promiscuous multi-target interactions, in a manner that cannot be understood by a static structural view.
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30
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Nishida N, Osawa M, Takeuchi K, Imai S, Stampoulis P, Kofuku Y, Ueda T, Shimada I. Functional dynamics of cell surface membrane proteins. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2014; 241:86-96. [PMID: 24331735 DOI: 10.1016/j.jmr.2013.11.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2013] [Revised: 11/08/2013] [Accepted: 11/11/2013] [Indexed: 06/03/2023]
Abstract
Cell surface receptors are integral membrane proteins that receive external stimuli, and transmit signals across plasma membranes. In the conventional view of receptor activation, ligand binding to the extracellular side of the receptor induces conformational changes, which convert the structure of the receptor into an active conformation. However, recent NMR studies of cell surface membrane proteins have revealed that their structures are more dynamic than previously envisioned, and they fluctuate between multiple conformations in an equilibrium on various timescales. In addition, NMR analyses, along with biochemical and cell biological experiments indicated that such dynamical properties are critical for the proper functions of the receptors. In this review, we will describe several NMR studies that revealed direct linkage between the structural dynamics and the functions of the cell surface membrane proteins, such as G-protein coupled receptors (GPCRs), ion channels, membrane transporters, and cell adhesion molecules.
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Affiliation(s)
- Noritaka Nishida
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Masanori Osawa
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Koh Takeuchi
- Molecular Profiling Research Center, National Institute of Advanced Industrial Science and Technology, Aomi, Koto-ku, Tokyo 135-0064, Japan
| | - Shunsuke Imai
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Pavlos Stampoulis
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Yutaka Kofuku
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Takumi Ueda
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Ichio Shimada
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
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31
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Zheng X, Pedersen LC, Gabel SA, Mueller GA, Cuneo MJ, DeRose EF, Krahn JM, London RE. Selective unfolding of one Ribonuclease H domain of HIV reverse transcriptase is linked to homodimer formation. Nucleic Acids Res 2014; 42:5361-77. [PMID: 24574528 PMCID: PMC4005681 DOI: 10.1093/nar/gku143] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
HIV-1 reverse transcriptase (RT), a critical enzyme of the HIV life cycle and an important drug target, undergoes complex and largely uncharacterized conformational rearrangements that underlie its asymmetric folding, dimerization and subunit-selective ribonuclease H domain (RH) proteolysis. In the present article we have used a combination of NMR spectroscopy, small angle X-ray scattering and X-ray crystallography to characterize the p51 and p66 monomers and the conformational maturation of the p66/p66′ homodimer. The p66 monomer exists as a loosely structured molecule in which the fingers/palm/connection, thumb and RH substructures are connected by flexible (disordered) linking segments. The initially observed homodimer is asymmetric and includes two fully folded RH domains, while exhibiting other conformational features similar to that of the RT heterodimer. The RH′ domain of the p66′ subunit undergoes selective unfolding with time constant ∼6.5 h, consistent with destabilization due to residue transfer to the polymerase′ domain on the p66′ subunit. A simultaneous increase in the intensity of resonances near the random coil positions is characterized by a similar time constant. Consistent with the residue transfer hypothesis, a construct of the isolated RH domain lacking the two N-terminal residues is shown to exhibit reduced stability. These results demonstrate that RH′ unfolding is coupled to homodimer formation.
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Affiliation(s)
- Xunhai Zheng
- Laboratory of Structural Biology, NIEHS, National Institutes of Health, Research Triangle Park, NC 27709, USA
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32
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Tuttle LM, Dyson HJ, Wright PE. Side chain conformational averaging in human dihydrofolate reductase. Biochemistry 2014; 53:1134-45. [PMID: 24498949 PMCID: PMC3985697 DOI: 10.1021/bi4015314] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
![]()
The three-dimensional structures
of the dihydrofolate reductase
enzymes from Escherichia coli (ecDHFR or ecE) and Homo sapiens (hDHFR or hE) are very similar, despite a rather
low level of sequence identity. Whereas the active site loops of ecDHFR
undergo major conformational rearrangements during progression through
the reaction cycle, hDHFR remains fixed in a closed loop conformation
in all of its catalytic intermediates. To elucidate the structural
and dynamic differences between the human and E. coli enzymes, we conducted a comprehensive analysis of side chain flexibility
and dynamics in complexes of hDHFR that represent intermediates in
the major catalytic cycle. Nuclear magnetic resonance relaxation dispersion
experiments show that, in marked contrast to the functionally important
motions that feature prominently in the catalytic intermediates of
ecDHFR, millisecond time scale fluctuations cannot be detected for
hDHFR side chains. Ligand flux in hDHFR is thought to be mediated
by conformational changes between a hinge-open state when the substrate/product-binding
pocket is vacant and a hinge-closed state when this pocket is occupied.
Comparison of X-ray structures of hinge-open and hinge-closed states
shows that helix αF changes position by sliding between the
two states. Analysis of χ1 rotamer populations derived
from measurements of 3JCγCO and 3JCγN couplings
indicates that many of the side chains that contact helix αF
exhibit rotamer averaging that may facilitate the conformational change.
The χ1 rotamer adopted by the Phe31 side chain depends
upon whether the active site contains the substrate or product. In
the holoenzyme (the binary complex of hDHFR with reduced nicotinamide
adenine dinucleotide phosphate), a combination of hinge opening and
a change in the Phe31 χ1 rotamer opens the active
site to facilitate entry of the substrate. Overall, the data suggest
that, unlike ecDHFR, hDHFR requires minimal backbone conformational
rearrangement as it proceeds through its enzymatic cycle, but that
ligand flux is brokered by more subtle conformational changes that
depend on the side chain motions of critical residues.
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Affiliation(s)
- Lisa M Tuttle
- Department of Integrative Structural and Computational Biology and Skaggs Institute for Chemical Biology, The Scripps Research Institute , 10550 North Torrey Pines Road, La Jolla, California 92037, United States
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33
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Ab Initio Calculations of Possible γ-Gauche Effects in the 13C-NMR for Methine and Carbonyl Carbons in Precise Polyethylene Acrylic Acid Copolymers. Molecules 2013; 18:9010-20. [PMID: 23899834 PMCID: PMC6269996 DOI: 10.3390/molecules18089010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2013] [Revised: 07/19/2013] [Accepted: 07/23/2013] [Indexed: 12/03/2022] Open
Abstract
The impacts of local polymer chain conformations on the methine and carbonyl 13C-NMR chemical shifts for polyethylene acrylic acid p(E-AA) copolymers were predicted using ab initio methods. Using small molecular cluster models, the magnitude and sign of the γ-gauche torsional angle effect, along with the impact of local tetrahedral structure distortions near the carbonyl group, on the 13C-NMR chemical shifts were determined. These 13C-NMR chemical shift variations were compared to the experimental trends observed for precise p(E-AA) copolymers as a function acid group spacing and degree of zinc-neutralization in the corresponding p(E-AA) ionomers. These ab initio calculations address the future ability of 13C-NMR chemical shift variations to provide information about the local chain conformations in p(E-AA) copolymer materials.
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34
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Brüschweiler S, Konrat R, Tollinger M. Allosteric communication in the KIX domain proceeds through dynamic repacking of the hydrophobic core. ACS Chem Biol 2013; 8:1600-10. [PMID: 23651431 PMCID: PMC3719477 DOI: 10.1021/cb4002188] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
![]()
The KIX domain of the transcriptional
coactivator CREB binding
protein (CBP) co-operatively mediates interactions between transcription
factors. Binding of the transcription factor mixed-lineage leukemia
(MLL) induces the formation of a low-populated conformer of KIX that
resembles the conformation of the KIX domain in the presence of a
second transcription factor molecule. NMR spin relaxation studies
have previously shown that allosteric coupling proceeds through a
network of hydrophobic core residues that bridge the two binding sites.
Here we describe high-resolution NMR solution structures of the binary
complex of KIX with MLL and the ternary complex of KIX formed with
MLL and phosphorylated kinase inducible domain of CREB (pKID) as a
second ligand. We show that binding of pKID to the binary complex
of KIX with MLL is accompanied by a defined repacking of the allosteric
network in the hydrophobic core of the protein. Rotamer populations
derived from methyl group 13C chemical shifts reveal a
dynamic contribution to the repacking process that is not captured
by the structural coordinates and exemplify the dynamic nature of
allosteric communication in the KIX domain.
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Affiliation(s)
- Sven Brüschweiler
- Institute of Organic Chemistry, Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innrain 80/82, A-6020 Innsbruck, Austria
- Structural and Computational Biology, Max F. Perutz Laboratories, Campus Vienna Biocenter 5, A-1030 Vienna, Austria
| | - Robert Konrat
- Structural and Computational Biology, Max F. Perutz Laboratories, Campus Vienna Biocenter 5, A-1030 Vienna, Austria
| | - Martin Tollinger
- Institute of Organic Chemistry, Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innrain 80/82, A-6020 Innsbruck, Austria
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35
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Goursot A, Mineva T, Vásquez-Pérez JM, Calaminici P, Köster AM, Salahub DR. Contribution of high-energy conformations to NMR chemical shifts, a DFT-BOMD study. Phys Chem Chem Phys 2013. [PMID: 23202583 DOI: 10.1039/c2cp43514d] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This paper highlights the relevance of including the high-energy conformational states sampled by Born-Oppenheimer molecular dynamics (BOMD) in the calculation of time-averaged NMR chemical shifts. Our case study is the very flexible glycerol molecule that undergoes interconversion between conformers in a nonrandom way. Along the sequence of structures from one backbone conformer to another, transition states have been identified. The three (13)C NMR chemical shifts of the molecule were estimated by averaging their calculated values over a large set of BOMD snapshots. The simulation time needed to obtain a good agreement with the two signals present in the experimental spectrum is shown to be dependent on the atomic orbital basis set used for the dynamics, with a necessary longer trajectory for the most extended basis sets. The large structural deformations with respect to the optimized conformer geometries that occur along the dynamics are related to a kinetically driven conformer distribution. Calculated conformer type populations are in good agreement with experimental gas phase microwave results.
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Affiliation(s)
- A Goursot
- ICGM, UMR 5253 CNRS, Ecole de chimie de Montpellier, 8 rue de l'Ecole Normale, 34296 Montpellier, Cédex 5, France.
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36
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Kjaergaard M, Andersen L, Nielsen LD, Teilum K. A Folded Excited State of Ligand-Free Nuclear Coactivator Binding Domain (NCBD) Underlies Plasticity in Ligand Recognition. Biochemistry 2013; 52:1686-93. [DOI: 10.1021/bi4001062] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Magnus Kjaergaard
- Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, 2200
Copenhagen N, Denmark
| | - Lisbeth Andersen
- Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, 2200
Copenhagen N, Denmark
| | - Lau Dalby Nielsen
- Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, 2200
Copenhagen N, Denmark
| | - Kaare Teilum
- Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, 2200
Copenhagen N, Denmark
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37
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Kofuku Y, Ueda T, Okude J, Shiraishi Y, Kondo K, Maeda M, Tsujishita H, Shimada I. Efficacy of the β₂-adrenergic receptor is determined by conformational equilibrium in the transmembrane region. Nat Commun 2013; 3:1045. [PMID: 22948827 PMCID: PMC3658005 DOI: 10.1038/ncomms2046] [Citation(s) in RCA: 155] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2012] [Accepted: 08/02/2012] [Indexed: 12/18/2022] Open
Abstract
Many drugs that target G-protein-coupled receptors (GPCRs) induce or inhibit their signal transduction with different strengths, which affect their therapeutic properties. However, the mechanism underlying the differences in the signalling levels is still not clear, although several structures of GPCRs complexed with ligands determined by X-ray crystallography are available. Here we utilized NMR to monitor the signals from the methionine residue at position 82 in neutral antagonist- and partial agonist-bound states of β2-adrenergic receptor (β2AR), which are correlated with the conformational changes of the transmembrane regions upon activation. We show that this residue exists in a conformational equilibrium between the inverse agonist-bound states and the full agonist-bound state, and the population of the latter reflects the signal transduction level in each ligand-bound state. These findings provide insights into the multi-level signalling of β2AR and other GPCRs, including the basal activity, and the mechanism of signal transduction mediated by GPCRs. Many drugs exist that target the β-adrenergic receptor, but they have different efficacies. Kofuku et al. use NMR to show that methionine 82 in the transmembrane domain undergoes conformational changes depending on whether agonists or inverse agonists are bound, explaining the differential drug efficacy.
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Affiliation(s)
- Yutaka Kofuku
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan
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38
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De Sa Peixoto P, Laurent G, Azaïs T, Mosser G. Solid-state NMR study reveals collagen I structural modifications of amino acid side chains upon fibrillogenesis. J Biol Chem 2013; 288:7528-7535. [PMID: 23341452 DOI: 10.1074/jbc.m112.390146] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In vivo, collagen I, the major structural protein in human body, is found assembled into fibrils. In the present work, we study a high concentrated collagen sample in its soluble, fibrillar, and denatured states using one and two dimensional {(1)H}-(13)C solid-state NMR spectroscopy. We interpret (13)C chemical shift variations in terms of dihedral angle conformation changes. Our data show that fibrillogenesis increases the side chain and backbone structural complexity. Nevertheless, only three to five rotameric equilibria are found for each amino acid residue, indicating a relatively low structural heterogeneity of collagen upon fibrillogenesis. Using side chain statistical data, we calculate equilibrium constants for a great number of amino acid residues. Moreover, based on a (13)C quantitative spectrum, we estimate the percentage of residues implicated in each equilibrium. Our data indicate that fibril formation greatly affects hydroxyproline and proline prolyl pucker ring conformation. Finally, we discuss the implication of these structural data and propose a model in which the attractive force of fibrillogenesis comes from a structural reorganization of 10 to 15% of the amino acids. These results allow us to further understand the self-assembling process and fibrillar structure of collagen.
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Affiliation(s)
- Paulo De Sa Peixoto
- Laboratoire de Chimie de la Matière Condensée de Paris, UMR 7574 Université Pierre et Marie Curie (UPMC)/Centre National de La Recherche Scientifique (CNRS)/Collège de France, UPMC, 4 place Jussieu, 75005 Paris, France
| | - Guillaume Laurent
- Laboratoire de Chimie de la Matière Condensée de Paris, UMR 7574 Université Pierre et Marie Curie (UPMC)/Centre National de La Recherche Scientifique (CNRS)/Collège de France, UPMC, 4 place Jussieu, 75005 Paris, France
| | - Thierry Azaïs
- Laboratoire de Chimie de la Matière Condensée de Paris, UMR 7574 Université Pierre et Marie Curie (UPMC)/Centre National de La Recherche Scientifique (CNRS)/Collège de France, UPMC, 4 place Jussieu, 75005 Paris, France
| | - Gervaise Mosser
- Laboratoire de Chimie de la Matière Condensée de Paris, UMR 7574 Université Pierre et Marie Curie (UPMC)/Centre National de La Recherche Scientifique (CNRS)/Collège de France, UPMC, 4 place Jussieu, 75005 Paris, France.
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39
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Tian Y, Opella SJ, Marassi FM. Improved chemical shift prediction by Rosetta conformational sampling. JOURNAL OF BIOMOLECULAR NMR 2012; 54:237-243. [PMID: 23007199 PMCID: PMC3484222 DOI: 10.1007/s10858-012-9677-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2012] [Accepted: 09/16/2012] [Indexed: 06/01/2023]
Abstract
Chemical shift frequencies represent a time-average of all the conformational states populated by a protein. Thus, chemical shift prediction programs based on sequence and database analysis yield higher accuracy for rigid rather than flexible protein segments. Here we show that the prediction accuracy can be significantly improved by averaging over an ensemble of structures, predicted solely from amino acid sequence with the Rosetta program. This approach to chemical shift and structure prediction has the potential to be useful for guiding resonance assignments, especially in solid-state NMR structural studies of membrane proteins in proteoliposomes.
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Affiliation(s)
- Ye Tian
- Sanford Burnham Medical Research Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA
- Department of Chemistry and Biochemistry, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0307, USA
| | - Stanley J. Opella
- Department of Chemistry and Biochemistry, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0307, USA
| | - Francesca M. Marassi
- Sanford Burnham Medical Research Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA
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40
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Zheng X, Mueller GA, DeRose EF, London RE. Metal and ligand binding to the HIV-RNase H active site are remotely monitored by Ile556. Nucleic Acids Res 2012; 40:10543-53. [PMID: 22941642 PMCID: PMC3488238 DOI: 10.1093/nar/gks791] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2012] [Revised: 07/26/2012] [Accepted: 07/27/2012] [Indexed: 11/14/2022] Open
Abstract
HIV-1 reverse transcriptase (RT) contains a C-terminal ribonuclease H (RH) domain on its p66 subunit that can be expressed as a stable, although inactive protein. Recent studies of several RH enzymes demonstrate that substrate binding plays a major role in the creation of the active site. In the absence of substrate, the C-terminal helix E of the RT RNase H domain is dynamic, characterized by severe exchange broadening of its backbone amide resonances, so that the solution characterization of this region of the protein has been limited. Nuclear magnetic resonance studies of 13C-labeled RH as a function of experimental conditions reveal that the δ1 methyl resonance of Ile556, located in a short, random coil segment following helix E, experiences a large 13C shift corresponding to a conformational change of Ile556 that results from packing of helix E against the central β-sheet. This shift provides a useful basis for monitoring the effects of various ligands on active site formation. Additionally, we report that the RNase H complexes formed with one or both divalent ions can be individually observed and characterized using diamagnetic Zn2+ as a substitute for Mg2+. Ordering of helix E results specifically from the interaction with the lower affinity binding to the A divalent ion site.
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Affiliation(s)
| | | | | | - Robert E. London
- Laboratory of Structural Biology, NIEHS, National Institutes of Health, Research Triangle Park, NC 27709, USA
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41
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Barraud P, Schubert M, Allain FHT. A strong 13C chemical shift signature provides the coordination mode of histidines in zinc-binding proteins. JOURNAL OF BIOMOLECULAR NMR 2012; 53:93-101. [PMID: 22528293 DOI: 10.1007/s10858-012-9625-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2012] [Accepted: 03/30/2012] [Indexed: 05/31/2023]
Abstract
Zinc is the second most abundant metal ion incorporated in proteins, and is in many cases a crucial component of protein three-dimensional structures. Zinc ions are frequently coordinated by cysteine and histidine residues. Whereas cysteines bind to zinc via their unique S(γ) atom, histidines can coordinate zinc with two different coordination modes, either N(δ1) or N(ε2) is coordinating the zinc ion. The determination of this coordination mode is crucial for the accurate structure determination of a histidine-containing zinc-binding site by NMR. NMR chemical shifts contain a vast amount of information on local electronic and structural environments and surprisingly their utilization for the determination of the coordination mode of zinc-ligated histidines has been limited so far to (15)N nuclei. In the present report, we observed that the (13)C chemical shifts of aromatic carbons in zinc-ligated histidines represent a reliable signature of their coordination mode. Using a statistical analysis of (13)C chemical shifts, we show that (13)C(δ2) chemical shift is sensitive to the histidine coordination mode and that the chemical shift difference δ{(13)C(ε1)} - δ{(13)C(δ2)} provides a reference-independent marker of this coordination mode. The present approach allows the direct determination of the coordination mode of zinc-ligated histidines even with non-isotopically enriched protein samples and without any prior structural information.
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Affiliation(s)
- Pierre Barraud
- Institute of Molecular Biology and Biophysics, ETH Zurich, Schafmattstrasse 20, 8093 Zurich, Switzerland.
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Kjaergaard M, Poulsen FM, Teilum K. Is a malleable protein necessarily highly dynamic? The hydrophobic core of the nuclear coactivator binding domain is well ordered. Biophys J 2012; 102:1627-35. [PMID: 22500763 DOI: 10.1016/j.bpj.2012.02.014] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2011] [Revised: 01/11/2012] [Accepted: 02/06/2012] [Indexed: 02/03/2023] Open
Abstract
The nuclear coactivator binding domain of CREB binding protein folds into remarkably different structures in complex with different ligands. To understand the mechanism of the structural adaptability in the nuclear coactivator binding domain (NCBD), we have compared the dynamics of the hydrophobic core of NCBD in the ligand-free state and in a well-folded complex with the ligand activator for thyroid hormone and retinoid receptors using multiple NMR methods including methyl chemical shifts, coupling constants, and methyl order parameters. From all NMR measures, the aliphatic side chains in the hydrophobic core are slightly more dynamic in the free protein than in the complex, but have mobility comparable to the hydrophobic cores of average folded proteins. Urea titration monitored by NMR reveals that all parts of the protein, including the side-chain packing in the hydrophobic core, denatures in a single cooperative process. The molten globule characteristics of NCBD are thus restricted to a slowly fluctuating tertiary structure. Consequently, the conformational plasticity of the protein is most likely related to its low overall stability rather than an intrinsically flexible protein structure. The well-defined structure supports a model of molecular recognition dominated by conformational selection, whereas only minor structural adjustments are necessary after the association.
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Affiliation(s)
- Magnus Kjaergaard
- Department of Biology, University of Copenhagen, Copenhagen, Denmark
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43
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Kjaergaard M, Iešmantavičius V, Poulsen FM. The interplay between transient α-helix formation and side chain rotamer distributions in disordered proteins probed by methyl chemical shifts. Protein Sci 2012; 20:2023-34. [PMID: 21898648 DOI: 10.1002/pro.726] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The peptide backbones of disordered proteins are routinely characterized by NMR with respect to transient structure and dynamics. Little experimental information is, however, available about the side chain conformations and how structure in the backbone affects the side chains. Methyl chemical shifts can in principle report the conformations of aliphatic side chains in disordered proteins and in order to examine this two model systems were chosen: the acid denatured state of acyl-CoA binding protein (ACBP) and the intrinsically disordered activation domain of the activator for thyroid hormone and retinoid receptors (ACTR). We find that small differences in the methyl carbon chemical shifts due to the γ-gauche effect may provide information about the side chain rotamer distributions. However, the effects of neighboring residues on the methyl group chemical shifts obscure the direct observation of γ-gauche effect. To overcome this, we reference the chemical shifts to those in a more disordered state resulting in residue specific random coil chemical shifts. The (13)C secondary chemical shifts of the methyl groups of valine, leucine, and isoleucine show sequence specific effects, which allow a quantitative analysis of the ensemble of χ(2)-angles of especially leucine residues in disordered proteins. The changes in the rotamer distributions upon denaturation correlate to the changes upon helix induction by the co-solvent trifluoroethanol, suggesting that the side chain conformers are directly or indirectly related to formation of transient α-helices.
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Affiliation(s)
- Magnus Kjaergaard
- Department of Biology, University of Copenhagen, København N, Denmark
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Kjaergaard M, Poulsen FM. Disordered proteins studied by chemical shifts. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2012; 60:42-51. [PMID: 22293398 DOI: 10.1016/j.pnmrs.2011.10.001] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2011] [Accepted: 10/06/2011] [Indexed: 05/31/2023]
Affiliation(s)
- Magnus Kjaergaard
- Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, DK-2200 København N, Denmark
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Kleckner IR, Gollnick P, Foster MP. Mechanisms of allosteric gene regulation by NMR quantification of microsecond-millisecond protein dynamics. J Mol Biol 2011; 415:372-81. [PMID: 22115774 DOI: 10.1016/j.jmb.2011.11.019] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2011] [Revised: 10/17/2011] [Accepted: 11/08/2011] [Indexed: 11/17/2022]
Abstract
The trp RNA-binding attenuation protein (TRAP) is a paradigmatic allosteric protein that regulates the tryptophan biosynthetic genes associated with the trp operon in bacilli. The ring-shaped 11-mer TRAP is activated for recognition of a specific trp-mRNA target by binding up to 11 tryptophan molecules. To characterize the mechanisms of tryptophan-induced TRAP activation, we have performed methyl relaxation dispersion (MRD) nuclear magnetic resonance (NMR) experiments that probe the time-dependent structure of TRAP in the microsecond-to-millisecond "chemical exchange" time window. We find significant side chain flexibility localized to the RNA and tryptophan binding sites of the apo protein and that these dynamics are dramatically reduced upon ligand binding. Analysis of the MRD NMR data provides insights into the structural nature of transiently populated conformations sampled in solution by apo TRAP. The MRD data are inconsistent with global two-state exchange, indicating that conformational sampling in apo TRAP is asynchronous. These findings imply a temporally heterogeneous population of structures that are incompatible with RNA binding and substantiate the study of TRAP as a paradigm for probing and understanding essential dynamics in allosteric, regulatory proteins.
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Affiliation(s)
- Ian R Kleckner
- Biophysics Program, Ohio State University, 484 West 12th Avenue, Columbus, OH 43210, USA
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46
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Sahakyan AB, Vranken WF, Cavalli A, Vendruscolo M. Using Side-Chain Aromatic Proton Chemical Shifts for a Quantitative Analysis of Protein Structures. Angew Chem Int Ed Engl 2011. [DOI: 10.1002/ange.201101641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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47
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Schanda P, Huber M, Boisbouvier J, Meier BH, Ernst M. Solid-State NMR Measurements of Asymmetric Dipolar Couplings Provide Insight into Protein Side-Chain Motion. Angew Chem Int Ed Engl 2011; 50:11005-9. [DOI: 10.1002/anie.201103944] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2011] [Indexed: 11/05/2022]
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48
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Schanda P, Huber M, Boisbouvier J, Meier BH, Ernst M. Asymmetrische dipolare Kopplungen aus Festkörper-NMR-Messungen geben Einblick in die Bewegung von Seitenketten in Proteinen. Angew Chem Int Ed Engl 2011. [DOI: 10.1002/ange.201103944] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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49
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Sahakyan AB, Vranken WF, Cavalli A, Vendruscolo M. Using side-chain aromatic proton chemical shifts for a quantitative analysis of protein structures. Angew Chem Int Ed Engl 2011; 50:9620-3. [PMID: 21887824 DOI: 10.1002/anie.201101641] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2011] [Indexed: 12/14/2022]
Affiliation(s)
- Aleksandr B Sahakyan
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK
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50
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Sahakyan AB, Vranken WF, Cavalli A, Vendruscolo M. Structure-based prediction of methyl chemical shifts in proteins. JOURNAL OF BIOMOLECULAR NMR 2011; 50:331-46. [PMID: 21748266 DOI: 10.1007/s10858-011-9524-2] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2011] [Accepted: 05/17/2011] [Indexed: 05/07/2023]
Abstract
Protein methyl groups have recently been the subject of much attention in NMR spectroscopy because of the opportunities that they provide to obtain information about the structure and dynamics of proteins and protein complexes. With the advent of selective labeling schemes, methyl groups are particularly interesting in the context of chemical shift based protein structure determination, an approach that to date has exploited primarily the mapping between protein structures and backbone chemical shifts. In order to extend the scope of chemical shifts for structure determination, we present here the CH3Shift method of performing structure-based predictions of methyl chemical shifts. The terms considered in the predictions take account of ring current, magnetic anisotropy, electric field, rotameric type, and dihedral angle effects, which are considered in conjunction with polynomial functions of interatomic distances. We show that the CH3Shift method achieves an accuracy in the predictions that ranges from 0.133 to 0.198 ppm for (1)H chemical shifts for Ala, Thr, Val, Leu and Ile methyl groups. We illustrate the use of the method by assessing the accuracy of side-chain structures in structural ensembles representing the dynamics of proteins.
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Affiliation(s)
- Aleksandr B Sahakyan
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK
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