51
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Shekar SC, Zhao W, Weldeghiorghis TK, Wang T. Effect of cross polarization radiofrequency phases on signal phase. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2022; 117:101771. [PMID: 34973555 DOI: 10.1016/j.ssnmr.2021.101771] [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: 08/22/2021] [Revised: 12/19/2021] [Accepted: 12/20/2021] [Indexed: 06/14/2023]
Abstract
Utilizing phases of radio frequency (RF) pulses to manipulate spin dynamics is routine in NMR and MRI, leading to spectacular techniques like phase cycling. In a very different area, cross polarization (CP) also has a long history as part of a vast number of solid-state NMR pulse sequences. However, a detailed study devoted to the effect of CP RF phases on NMR signal, seems not to be readily available. From first principles, we arrive at a simple dependence of NMR signal on arbitrary CP RF phases, for static and MAS conditions, accompanied by experimental verification. In the process, the CP propagator emerges as a product of RF "pulses" and a period of "free precession", conforming to coherence transfer pathway theory. The theoretical expressions may lend confidence for dealing with CP blocks with tunable phases in pulse sequences.
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Affiliation(s)
- S Chandra Shekar
- Department of Chemistry, Louisiana State University, Baton Rouge, LA, 70803, USA.
| | - Wancheng Zhao
- Department of Chemistry, Louisiana State University, Baton Rouge, LA, 70803, USA
| | | | - Tuo Wang
- Department of Chemistry, Louisiana State University, Baton Rouge, LA, 70803, USA.
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52
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Duan P, Chen KJ, Wijegunawardena G, Dregni AJ, Wang HK, Wu H, Hong M. Binding Sites of a Positron Emission Tomography Imaging Agent in Alzheimer's β-Amyloid Fibrils Studied Using 19F Solid-State NMR. J Am Chem Soc 2022; 144:1416-1430. [PMID: 35015530 PMCID: PMC8855532 DOI: 10.1021/jacs.1c12056] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Amyloid imaging by positron emission tomography (PET) is an important method for diagnosing neurodegenerative disorders such as Alzheimer's disease. Many 11C- and 18F-labeled PET tracers show varying binding capacities, specificities, and affinities for their target proteins. The structural basis of these variations is poorly understood. Here we employ 19F and 13C solid-state NMR to investigate the binding sites of a PET ligand, flutemetamol, to the 40-residue Alzheimer's β-amyloid peptide (Aβ40). Analytical high-performance liquid chromatography and 19F NMR spectra show that flutemetamol binds the current Aβ40 fibril polymorph with a stoichiometry of one ligand per four to five peptides. Half of the ligands are tightly bound while the other half are loosely bound. 13C and 15N chemical shifts indicate that this Aβ40 polymorph has an immobilized N-terminus, a non-β-sheet His14, and a non-β-sheet C-terminus. We measured the proximity of the ligand fluorine to peptide residues using 19F-13C and 19F-1H rotational-echo double-resonance (REDOR) experiments. The spectra show that three segments in the peptide, 12VHH14, 18VFF20, and 39VV40, lie the closest to the ligand. REDOR-constrained docking simulations indicate that these three segments form multiple binding sites, and the ligand orientations and positions at these sites are similar across different Aβ polymorphs. Comparison of the flutemetamol-interacting residues in Aβ40 with the small-molecule binding sites in other amyloid proteins suggest that conjugated aromatic compounds preferentially bind β-sheet surface grooves lined by aromatic, polar, and charged residues. These motifs may explain the specificity of different PET tracers to different amyloid proteins.
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Affiliation(s)
- Pu Duan
- Department of Chemistry, Massachusetts Institute of Technology, 170 Albany Street, Cambridge, MA 02139, United States
| | - Kelly J. Chen
- Department of Chemistry, Massachusetts Institute of Technology, 170 Albany Street, Cambridge, MA 02139, United States
| | - Gayani Wijegunawardena
- Department of Chemistry and Biochemistry, Wichita State University, 1845 Fairmount St, Wichita, KS 67260, United States
| | - Aurelio J. Dregni
- Department of Chemistry, Massachusetts Institute of Technology, 170 Albany Street, Cambridge, MA 02139, United States
| | - Harrison K. Wang
- Department of Chemistry, Massachusetts Institute of Technology, 170 Albany Street, Cambridge, MA 02139, United States
| | - Haifan Wu
- Department of Chemistry and Biochemistry, Wichita State University, 1845 Fairmount St, Wichita, KS 67260, United States
| | - Mei Hong
- Department of Chemistry, Massachusetts Institute of Technology, 170 Albany Street, Cambridge, MA 02139, United States
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53
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Liang L, Ji Y, Chen K, Gao P, Zhao Z, Hou G. Solid-State NMR Dipolar and Chemical Shift Anisotropy Recoupling Techniques for Structural and Dynamical Studies in Biological Systems. Chem Rev 2022; 122:9880-9942. [PMID: 35006680 DOI: 10.1021/acs.chemrev.1c00779] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
With the development of NMR methodology and technology during the past decades, solid-state NMR (ssNMR) has become a particularly important tool for investigating structure and dynamics at atomic scale in biological systems, where the recoupling techniques play pivotal roles in modern high-resolution MAS NMR. In this review, following a brief introduction on the basic theory of recoupling in ssNMR, we highlight the recent advances in dipolar and chemical shift anisotropy recoupling methods, as well as their applications in structural determination and dynamical characterization at multiple time scales (i.e., fast-, intermediate-, and slow-motion). The performances of these prevalent recoupling techniques are compared and discussed in multiple aspects, together with the representative applications in biomolecules. Given the recent emerging advances in NMR technology, new challenges for recoupling methodology development and potential opportunities for biological systems are also discussed.
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Affiliation(s)
- Lixin Liang
- State Key Laboratory of Catalysis, National Laboratory for Clean Energy, 2011-Collaborative Innovation Center of Chemistry for Energy Materials, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Zhongshan Road 457, Dalian 116023, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yi Ji
- State Key Laboratory of Catalysis, National Laboratory for Clean Energy, 2011-Collaborative Innovation Center of Chemistry for Energy Materials, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Zhongshan Road 457, Dalian 116023, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Kuizhi Chen
- State Key Laboratory of Catalysis, National Laboratory for Clean Energy, 2011-Collaborative Innovation Center of Chemistry for Energy Materials, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Zhongshan Road 457, Dalian 116023, China
| | - Pan Gao
- State Key Laboratory of Catalysis, National Laboratory for Clean Energy, 2011-Collaborative Innovation Center of Chemistry for Energy Materials, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Zhongshan Road 457, Dalian 116023, China
| | - Zhenchao Zhao
- State Key Laboratory of Catalysis, National Laboratory for Clean Energy, 2011-Collaborative Innovation Center of Chemistry for Energy Materials, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Zhongshan Road 457, Dalian 116023, China
| | - Guangjin Hou
- State Key Laboratory of Catalysis, National Laboratory for Clean Energy, 2011-Collaborative Innovation Center of Chemistry for Energy Materials, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Zhongshan Road 457, Dalian 116023, China
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54
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Sundaria A, Liberta F, Savran D, Sarkar R, Rodina N, Peters C, Schwierz N, Haupt C, Schmidt M, Reif B. SAA fibrils involved in AA amyloidosis are similar in bulk and by single particle reconstitution: A MAS solid-state NMR study. J Struct Biol X 2022; 6:100069. [PMID: 35924280 PMCID: PMC9340516 DOI: 10.1016/j.yjsbx.2022.100069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Revised: 07/09/2022] [Accepted: 07/15/2022] [Indexed: 11/25/2022] Open
Abstract
AA amyloidosis is one of the most prevalent forms of systemic amyloidosis and affects both humans and other vertebrates. In this study, we compare MAS solid-state NMR data with a recent cryo-EM study of fibrils involving full-length murine SAA1.1. We address the question whether the specific requirements for the reconstitution of an amyloid fibril structure by cryo-EM can potentially yield a bias towards a particular fibril polymorph. We employ fibril seeds extracted from in to vivo material to imprint the fibril structure onto the biochemically produced protein. Sequential assignments yield the secondary structure elements in the fibril state. Long-range DARR and PAR experiments confirm largely the topology observed in the ex-vivo cryo-EM study. We find that the β-sheets identified in the NMR experiments are similar to the β-sheets found in the cryo-EM study, with the exception of amino acids 33–42. These residues cannot be assigned by solid-state NMR, while they adopt a stable β-sheet in the cryo-EM structure. We suggest that the differences between MAS solid-state NMR and cryo-EM data are a consequence of a second conformer involving residues 33–42. Moreover, we were able to characterize the dynamic C-terminal tail of SAA in the fibril state. The C-terminus is flexible, remains detached from the fibrils, and does not affect the SAA fibril structure as confirmed further by molecular dynamics simulations. As the C-terminus can potentially interact with other cellular components, binding to cellular targets can affect its accessibility for protease digestion.
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55
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Jaroszewicz M, Altenhof AR, Schurko RW, Frydman L. Sensitivity Enhancement by Progressive Saturation of the Proton Reservoir: A Solid-State NMR Analogue of Chemical Exchange Saturation Transfer. J Am Chem Soc 2021; 143:19778-19784. [PMID: 34793152 PMCID: PMC8640991 DOI: 10.1021/jacs.1c08277] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Indexed: 01/10/2023]
Abstract
Chemical exchange saturation transfer (CEST) enhances solution-state NMR signals of labile and otherwise invisible chemical sites, by indirectly detecting their signatures as a highly magnified saturation of an abundant resonance─for instance, the 1H resonance of water. Stimulated by this sensitivity magnification, this study presents PROgressive Saturation of the Proton Reservoir (PROSPR), a method for enhancing the NMR sensitivity of dilute heteronuclei in static solids. PROSPR aims at using these heteronuclei to progressively deplete the abundant 1H polarization found in most organic and several inorganic solids, and implements this 1H signal depletion in a manner that reflects the spectral intensities of the heteronuclei as a function of their chemical shifts or quadrupolar offsets. To achieve this, PROSPR uses a looped cross-polarization scheme that repeatedly depletes 1H-1H local dipolar order and then relays this saturation throughout the full 1H reservoir via spin-diffusion processes that act as analogues of chemical exchanges in the CEST experiment. Repeating this cross-polarization/spin-diffusion procedure multiple times results in an effective magnification of each heteronucleus's response that, when repeated in a frequency-stepped fashion, indirectly maps their NMR spectrum as sizable attenuations of the abundant 1H NMR signal. Experimental PROSPR examples demonstrate that, in this fashion, faithful wideline NMR spectra can be obtained. These 1H-detected heteronuclear NMR spectra can have their sensitivity enhanced by orders of magnitude in comparison to optimized direct-detect experiments targeting unreceptive nuclei at low natural abundance, using modest hardware requirements and conventional NMR equipment at room temperature.
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Affiliation(s)
- Michael
J. Jaroszewicz
- Department
of Chemical and Biological Physics, Weizmann
Institute of Science, Rehovot 7610001, Israel
| | - Adam R. Altenhof
- Department
of Chemistry and Biochemistry, Florida State
University, Tallahassee, Florida 32306, United States
- National
High Magnetic Field Laboratory, 1800 East Paul Dirac Drive, Tallahassee, Florida 32310, United States
| | - Robert W. Schurko
- Department
of Chemistry and Biochemistry, Florida State
University, Tallahassee, Florida 32306, United States
- National
High Magnetic Field Laboratory, 1800 East Paul Dirac Drive, Tallahassee, Florida 32310, United States
| | - Lucio Frydman
- Department
of Chemical and Biological Physics, Weizmann
Institute of Science, Rehovot 7610001, Israel
- National
High Magnetic Field Laboratory, 1800 East Paul Dirac Drive, Tallahassee, Florida 32310, United States
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56
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Chakraborty A, Fernando LD, Fang W, Dickwella Widanage MC, Wei P, Jin C, Fontaine T, Latgé JP, Wang T. A molecular vision of fungal cell wall organization by functional genomics and solid-state NMR. Nat Commun 2021; 12:6346. [PMID: 34732740 PMCID: PMC8566572 DOI: 10.1038/s41467-021-26749-z] [Citation(s) in RCA: 46] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Accepted: 10/21/2021] [Indexed: 12/16/2022] Open
Abstract
Vast efforts have been devoted to the development of antifungal drugs targeting the cell wall, but the supramolecular architecture of this carbohydrate-rich composite remains insufficiently understood. Here we compare the cell wall structure of a fungal pathogen Aspergillus fumigatus and four mutants depleted of major structural polysaccharides. High-resolution solid-state NMR spectroscopy of intact cells reveals a rigid core formed by chitin, β-1,3-glucan, and α-1,3-glucan, with galactosaminogalactan and galactomannan present in the mobile phase. Gene deletion reshuffles the composition and spatial organization of polysaccharides, with significant changes in their dynamics and water accessibility. The distribution of α-1,3-glucan in chemically isolated and dynamically distinct domains supports its functional diversity. Identification of valines in the alkali-insoluble carbohydrate core suggests a putative function in stabilizing macromolecular complexes. We propose a revised model of cell wall architecture which will improve our understanding of the structural response of fungal pathogens to stresses. The fungal cell wall is a complex structure composed mainly of glucans, chitin and glycoproteins. Here, the authors use solid-state NMR spectroscopy to assess the cell wall architecture of Aspergillus fumigatus, comparing wild-type cells and mutants lacking major structural polysaccharides, with insights into the distinct functions of these components.
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Affiliation(s)
- Arnab Chakraborty
- Department of Chemistry, Louisiana State University, Baton Rouge, LA, USA
| | | | - Wenxia Fang
- State Key Laboratory of Non-food Biomass and Enzyme Technology, Guangxi Academy of Sciences, Nanning, China
| | | | - Pingzhen Wei
- State Key Laboratory of Non-food Biomass and Enzyme Technology, Guangxi Academy of Sciences, Nanning, China
| | - Cheng Jin
- State Key Laboratory of Non-food Biomass and Enzyme Technology, Guangxi Academy of Sciences, Nanning, China.,State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Thierry Fontaine
- Unité de Biologie et pathogénicité fongiques, INRAE, USC2019, Institut Pasteur, Paris, France
| | - Jean-Paul Latgé
- Institute of Molecular biology and Biotechnology (IMBBFORTH), University of Crete, Heraklion, Greece.
| | - Tuo Wang
- Department of Chemistry, Louisiana State University, Baton Rouge, LA, USA.
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57
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Aguion PI, Marchanka A. Strategies for RNA Resonance Assignment by 13C/ 15N- and 1H-Detected Solid-State NMR Spectroscopy. Front Mol Biosci 2021; 8:743181. [PMID: 34746232 PMCID: PMC8563574 DOI: 10.3389/fmolb.2021.743181] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2021] [Accepted: 09/03/2021] [Indexed: 12/27/2022] Open
Abstract
Magic angle spinning (MAS) solid-state NMR (ssNMR) is an established tool that can be applied to non-soluble or non-crystalline biomolecules of any size or complexity. The ssNMR method advances rapidly due to technical improvements and the development of advanced isotope labeling schemes. While ssNMR has shown significant progress in structural studies of proteins, the number of RNA studies remains limited due to ssNMR methodology that is still underdeveloped. Resonance assignment is the most critical and limiting step in the structure determination protocol that defines the feasibility of NMR studies. In this review, we summarize the recent progress in RNA resonance assignment methods and approaches for secondary structure determination by ssNMR. We critically discuss advantages and limitations of conventional 13C- and 15N-detected experiments and novel 1H-detected methods, identify optimal regimes for RNA studies by ssNMR, and provide our view on future ssNMR studies of RNA in large RNP complexes.
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Affiliation(s)
- Philipp Innig Aguion
- Institute for Organic Chemistry and Centre of Biomolecular Drug Research (BMWZ), Leibniz University Hannover, Hanover, Germany
| | - Alexander Marchanka
- Institute for Organic Chemistry and Centre of Biomolecular Drug Research (BMWZ), Leibniz University Hannover, Hanover, Germany
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58
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Li J, Sae Her A, Traaseth NJ. Asymmetric protonation of glutamate residues drives a preferred transport pathway in EmrE. Proc Natl Acad Sci U S A 2021; 118:e2110790118. [PMID: 34607959 PMCID: PMC8521673 DOI: 10.1073/pnas.2110790118] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/20/2021] [Indexed: 11/18/2022] Open
Abstract
EmrE is an Escherichia coli multidrug efflux pump and member of the small multidrug resistance (SMR) family that transports drugs as a homodimer by harnessing energy from the proton motive force. SMR family transporters contain a conserved glutamate residue in transmembrane 1 (Glu14 in EmrE) that is required for binding protons and drugs. Yet the mechanism underlying proton-coupled transport by the two glutamate residues in the dimer remains unresolved. Here, we used NMR spectroscopy to determine acid dissociation constants (pKa ) for wild-type EmrE and heterodimers containing one or two Glu14 residues in the dimer. For wild-type EmrE, we measured chemical shifts of the carboxyl side chain of Glu14 using solid-state NMR in lipid bilayers and obtained unambiguous evidence on the existence of asymmetric protonation states. Subsequent measurements of pKa values for heterodimers with a single Glu14 residue showed no significant differences from heterodimers with two Glu14 residues, supporting a model where the two Glu14 residues have independent pKa values and are not electrostatically coupled. These insights support a transport pathway with well-defined protonation states in each monomer of the dimer, including a preferred cytoplasmic-facing state where Glu14 is deprotonated in monomer A and protonated in monomer B under pH conditions in the cytoplasm of E. coli Our findings also lead to a model, hop-free exchange, which proposes how exchangers with conformation-dependent pKa values reduce proton leakage. This model is relevant to the SMR family and transporters comprised of inverted repeat domains.
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Affiliation(s)
- Jianping Li
- Department of Chemistry, New York University, New York, NY 10003
| | - Ampon Sae Her
- Department of Chemistry, New York University, New York, NY 10003
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59
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Dong XQ, Lin JY, Wang PF, Li Y, Wang J, Li B, Liao J, Lu JX. Solid-State NMR Studies of the Succinate-Acetate Permease from Citrobacter Koseri in Liposomes and Native Nanodiscs. Life (Basel) 2021; 11:life11090908. [PMID: 34575058 PMCID: PMC8471396 DOI: 10.3390/life11090908] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 08/26/2021] [Accepted: 08/27/2021] [Indexed: 11/24/2022] Open
Abstract
The succinate-acetate permease (SatP) is an anion channel with six transmembrane domains. It forms different oligomers, especially hexamers in the detergent as well as in the membrane. Solid-state NMR studies of SatP were carried out successfully on SatP complexes by reconstructing the protein into liposomes or retaining the protein in the native membrane of E. coli., where it was expressed. The comparison of 13C-13C 2D correlation spectra between the two samples showed great similarity, opening the possibility to further study the acetate transport mechanism of SatP in its native membrane environment. Solid-state NMR studies also revealed small chemical shift differences of SatP in the two different membrane systems, indicating the importance of the lipid environment in determining the membrane protein structures and dynamics. Combining different 2D SSNMR spectra, chemical shift assignments were made on some sites, consistent with the helical structures in the transmembrane domains. In the end, we pointed out the limitation in the sensitivity for membrane proteins with such a size, and also indicated possible ways to overcome it.
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Affiliation(s)
- Xing-Qi Dong
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China; (X.-Q.D.); (J.-Y.L.); (P.-F.W.); (Y.L.); (J.W.); (B.L.); (J.L.)
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai 200031, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jing-Yu Lin
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China; (X.-Q.D.); (J.-Y.L.); (P.-F.W.); (Y.L.); (J.W.); (B.L.); (J.L.)
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai 200031, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Peng-Fei Wang
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China; (X.-Q.D.); (J.-Y.L.); (P.-F.W.); (Y.L.); (J.W.); (B.L.); (J.L.)
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai 200031, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yi Li
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China; (X.-Q.D.); (J.-Y.L.); (P.-F.W.); (Y.L.); (J.W.); (B.L.); (J.L.)
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai 200031, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jian Wang
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China; (X.-Q.D.); (J.-Y.L.); (P.-F.W.); (Y.L.); (J.W.); (B.L.); (J.L.)
| | - Bing Li
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China; (X.-Q.D.); (J.-Y.L.); (P.-F.W.); (Y.L.); (J.W.); (B.L.); (J.L.)
| | - Jun Liao
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China; (X.-Q.D.); (J.-Y.L.); (P.-F.W.); (Y.L.); (J.W.); (B.L.); (J.L.)
| | - Jun-Xia Lu
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China; (X.-Q.D.); (J.-Y.L.); (P.-F.W.); (Y.L.); (J.W.); (B.L.); (J.L.)
- Correspondence:
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60
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Shoaib M, Chen Q, Shi X, Nair N, Prasanna C, Yang R, Walter D, Frederiksen KS, Einarsson H, Svensson JP, Liu CF, Ekwall K, Lerdrup M, Nordenskiöld L, Sørensen CS. Histone H4 lysine 20 mono-methylation directly facilitates chromatin openness and promotes transcription of housekeeping genes. Nat Commun 2021; 12:4800. [PMID: 34417450 PMCID: PMC8379281 DOI: 10.1038/s41467-021-25051-2] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 07/15/2021] [Indexed: 12/26/2022] Open
Abstract
Histone lysine methylations have primarily been linked to selective recruitment of reader or effector proteins that subsequently modify chromatin regions and mediate genome functions. Here, we describe a divergent role for histone H4 lysine 20 mono-methylation (H4K20me1) and demonstrate that it directly facilitates chromatin openness and accessibility by disrupting chromatin folding. Thus, accumulation of H4K20me1 demarcates highly accessible chromatin at genes, and this is maintained throughout the cell cycle. In vitro, H4K20me1-containing nucleosomal arrays with nucleosome repeat lengths (NRL) of 187 and 197 are less compact than unmethylated (H4K20me0) or trimethylated (H4K20me3) arrays. Concordantly, and in contrast to trimethylated and unmethylated tails, solid-state NMR data shows that H4K20 mono-methylation changes the H4 conformational state and leads to more dynamic histone H4-tails. Notably, the increased chromatin accessibility mediated by H4K20me1 facilitates gene expression, particularly of housekeeping genes. Altogether, we show how the methylation state of a single histone H4 residue operates as a focal point in chromatin structure control. While H4K20me1 directly promotes chromatin openness at highly transcribed genes, it also serves as a stepping-stone for H4K20me3-dependent chromatin compaction. The effect of histone H4 lysine 20 methylation (H4K20me) on chromatin accessibility are not well established. Here the authors show how H4K20 methylation regulates chromatin structure and accessibility to ensure precise transcriptional outputs through the cell cycle using genome-wide approaches, in vitro biophysical assays, and NMR.
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Affiliation(s)
- Muhammad Shoaib
- Biotech Research and Innovation Centre, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Department of Biology, SBA School of Science and Engineering, Lahore University of Management Sciences, Lahore, Pakistan
| | - Qinming Chen
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Xiangyan Shi
- School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, Singapore
| | - Nidhi Nair
- Biotech Research and Innovation Centre, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Chinmayi Prasanna
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Renliang Yang
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore.,Wilmar International Limited, Jurong Island, Singapore
| | - David Walter
- Biotech Research and Innovation Centre, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | | | - Hjorleifur Einarsson
- Biotech Research and Innovation Centre, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - J Peter Svensson
- Department of Biosciences and Nutrition, Karolinska Institute, Huddinge, Sweden
| | - Chuan Fa Liu
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Karl Ekwall
- Department of Biosciences and Nutrition, Karolinska Institute, Huddinge, Sweden
| | - Mads Lerdrup
- Center for Chromosome Stability, Department of Cellular and Molecular Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
| | - Lars Nordenskiöld
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore.
| | - Claus S Sørensen
- Biotech Research and Innovation Centre, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
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61
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Solid state NMR of membrane proteins: methods and applications. Biochem Soc Trans 2021; 49:1505-1513. [PMID: 34397082 DOI: 10.1042/bst20200070] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 07/17/2021] [Accepted: 07/27/2021] [Indexed: 12/30/2022]
Abstract
Membranes of cells are active barriers, in which membrane proteins perform essential remodelling, transport and recognition functions that are vital to cells. Membrane proteins are key regulatory components of cells and represent essential targets for the modulation of cell function and pharmacological intervention. However, novel folds, low molarity and the need for lipid membrane support present serious challenges to the characterisation of their structure and interactions. We describe the use of solid state NMR as a versatile and informative approach for membrane and membrane protein studies, which uniquely provides information on structure, interactions and dynamics of membrane proteins. High resolution approaches are discussed in conjunction with applications of NMR methods to studies of membrane lipid and protein structure and interactions. Signal enhancement in high resolution NMR spectra through DNP is discussed as a tool for whole cell and interaction studies.
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62
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Dregni AJ, Wang HK, Wu H, Duan P, Jin J, DeGrado WF, Hong M. Inclusion of the C-Terminal Domain in the β-Sheet Core of Heparin-Fibrillized Three-Repeat Tau Protein Revealed by Solid-State Nuclear Magnetic Resonance Spectroscopy. J Am Chem Soc 2021; 143:7839-7851. [PMID: 33983722 PMCID: PMC8283780 DOI: 10.1021/jacs.1c03314] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Many neurodegenerative diseases such as Alzheimer's disease are characterized by pathological β-sheet filaments of the tau protein, which spread in a prion-like manner in patient brains. To date, high-resolution structures of tau filaments obtained from patient brains show that the β-sheet core only includes portions of the microtubule-binding repeat domains and excludes the C-terminal residues, indicating that the C-terminus is dynamically disordered. Here, we use solid-state NMR spectroscopy to identify the β-sheet core of full-length 0N3R tau fibrillized using heparin. Assignment of 13C and 15N chemical shifts of the rigid core of the protein revealed a single predominant β-sheet conformation, which spans not only the R3, R4, R' repeats but also the entire C-terminal domain (CT) of the protein. This massive β-sheet core qualitatively differs from all other tau fibril structures known to date. Using long-range correlation NMR experiments, we found that the R3 and R4 repeats form a β-arch, similar to that seen in some of the brain-derived tau fibrils, but the R1 and R3 domains additionally stack against the CT, reminiscent of previously reported transient interactions of the CT with the microtubule-binding repeats. This expanded β-sheet core structure suggests that the CT may have a protective effect against the formation of pathological tau fibrils by shielding the amyloidogenic R3 and R4 domains, preventing side-on nucleation. Truncation and post-translational modification of the CT in vivo may thus play an important role in the progression of tauopathies.
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Affiliation(s)
- Aurelio J. Dregni
- Department of Chemistry, Massachusetts Institute of Technology, 170 Albany Street, Cambridge, MA 02139
| | - Harrison K. Wang
- Department of Chemistry, Massachusetts Institute of Technology, 170 Albany Street, Cambridge, MA 02139
| | - Haifan Wu
- Department of Pharmaceutical Chemistry, 555 Mission Bay Blvd. South, CVRB, Room 452V, University of California, San Francisco, CA 94158-9001
| | - Pu Duan
- Department of Chemistry, Massachusetts Institute of Technology, 170 Albany Street, Cambridge, MA 02139
| | - Jia Jin
- Department of Pharmaceutical Chemistry, 555 Mission Bay Blvd. South, CVRB, Room 452V, University of California, San Francisco, CA 94158-9001
| | - William F. DeGrado
- Department of Pharmaceutical Chemistry, 555 Mission Bay Blvd. South, CVRB, Room 452V, University of California, San Francisco, CA 94158-9001
| | - Mei Hong
- Department of Chemistry, Massachusetts Institute of Technology, 170 Albany Street, Cambridge, MA 02139
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63
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Li M, Sun W, Tyurin VA, DeLucia M, Ahn J, Kagan VE, van der Wel PCA. Activation of Cytochrome C Peroxidase Function Through Coordinated Foldon Loop Dynamics upon Interaction with Anionic Lipids. J Mol Biol 2021; 433:167057. [PMID: 34033821 DOI: 10.1016/j.jmb.2021.167057] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 05/07/2021] [Accepted: 05/13/2021] [Indexed: 02/06/2023]
Abstract
Cardiolipin (CL) is a mitochondrial anionic lipid that plays important roles in the regulation and signaling of mitochondrial apoptosis. CL peroxidation catalyzed by the assembly of CL-cytochrome c (cyt c) complexes at the inner mitochondrial membrane is a critical checkpoint. The structural changes in the protein, associated with peroxidase activation by CL and different anionic lipids, are not known at a molecular level. To better understand these peripheral protein-lipid interactions, we compare how phosphatidylglycerol (PG) and CL lipids trigger cyt c peroxidase activation, and correlate functional differences to structural and motional changes in membrane-associated cyt c. Structural and motional studies of the bound protein are enabled by magic angle spinning solid state NMR spectroscopy, while lipid peroxidase activity is assayed by mass spectrometry. PG binding results in a surface-bound state that preserves a nativelike fold, which nonetheless allows for significant peroxidase activity, though at a lower level than binding its native substrate CL. Lipid-specific differences in peroxidase activation are found to correlate to corresponding differences in lipid-induced protein mobility, affecting specific protein segments. The dynamics of omega loops C and D are upregulated by CL binding, in a way that is remarkably controlled by the protein:lipid stoichiometry. In contrast to complete chemical denaturation, membrane-induced protein destabilization reflects a destabilization of select cyt c foldons, while the energetically most stable helices are preserved. Our studies illuminate the interplay of protein and lipid dynamics in the creation of lipid peroxidase-active proteolipid complexes implicated in early stages of mitochondrial apoptosis.
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Affiliation(s)
- Mingyue Li
- Department of Structural Biology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Wanyang Sun
- Department of Environmental and Occupational Health, University of Pittsburgh, Pittsburgh, PA 15213, USA; Center for Free Radical and Antioxidant Health, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Vladimir A Tyurin
- Department of Environmental and Occupational Health, University of Pittsburgh, Pittsburgh, PA 15213, USA; Center for Free Radical and Antioxidant Health, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Maria DeLucia
- Department of Structural Biology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Jinwoo Ahn
- Department of Structural Biology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Valerian E Kagan
- Department of Environmental and Occupational Health, University of Pittsburgh, Pittsburgh, PA 15213, USA; Center for Free Radical and Antioxidant Health, University of Pittsburgh, Pittsburgh, PA 15213, USA; Department of Chemistry, University of Pittsburgh, Pittsburgh, PA 15213, USA; Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA 15213, USA; Institute for Regenerative Medicine, IM Sechenov, Moscow State Medical University, Moscow 119146, Russian Federation
| | - Patrick C A van der Wel
- Department of Structural Biology, University of Pittsburgh, Pittsburgh, PA 15213, USA; Zernike Institute for Advanced Materials, University of Groningen, Groningen, the Netherlands.
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64
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Zehnder J, Cadalbert R, Terradot L, Ernst M, Böckmann A, Güntert P, Meier BH, Wiegand T. Paramagnetic Solid-State NMR to Localize the Metal-Ion Cofactor in an Oligomeric DnaB Helicase. Chemistry 2021; 27:7745-7755. [PMID: 33822417 PMCID: PMC8252064 DOI: 10.1002/chem.202100462] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Indexed: 12/17/2022]
Abstract
Paramagnetic metal ions can be inserted into ATP-fueled motor proteins by exchanging the diamagnetic Mg2+ cofactor with Mn2+ or Co2+ . Then, paramagnetic relaxation enhancement (PRE) or pseudo-contact shifts (PCSs) can be measured to report on the localization of the metal ion within the protein. We determine the metal position in the oligomeric bacterial DnaB helicase from Helicobacter pylori complexed with the transition-state ATP-analogue ADP:AlF4 - and single-stranded DNA using solid-state NMR and a structure-calculation protocol employing CYANA. We discuss and compare the use of Mn2+ and Co2+ in localizing the ATP cofactor in large oligomeric protein assemblies. 31 P PCSs induced in the Co2+ -containing sample are then used to localize the DNA phosphate groups on the Co2+ PCS tensor surface enabling structural insights into DNA binding to the DnaB helicase.
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Affiliation(s)
- Johannes Zehnder
- Laboratorium für Physikalische ChemieETH ZürichVladimir-Prelog-Weg 28093ZürichSwitzerland
| | - Riccardo Cadalbert
- Laboratorium für Physikalische ChemieETH ZürichVladimir-Prelog-Weg 28093ZürichSwitzerland
| | | | - Matthias Ernst
- Laboratorium für Physikalische ChemieETH ZürichVladimir-Prelog-Weg 28093ZürichSwitzerland
| | | | - Peter Güntert
- Laboratorium für Physikalische ChemieETH ZürichVladimir-Prelog-Weg 28093ZürichSwitzerland
- Institute of Biophysical ChemistryCenter for Biomolecular Magnetic ResonanceGoethe University Frankfurt am Main60438Frankfurt am MainGermany
- Department of ChemistryTokyo Metropolitan UniversityHachiojiTokyo1920397Japan
| | - Beat H. Meier
- Laboratorium für Physikalische ChemieETH ZürichVladimir-Prelog-Weg 28093ZürichSwitzerland
| | - Thomas Wiegand
- Laboratorium für Physikalische ChemieETH ZürichVladimir-Prelog-Weg 28093ZürichSwitzerland
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65
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Xiao H, Zhang Z, Zhao Y, Yang J. Spectral editing of alanine, serine, and threonine in uniformly labeled proteins based on frequency-selective homonuclear recoupling in solid-state NMR. JOURNAL OF BIOMOLECULAR NMR 2021; 75:193-202. [PMID: 33890210 DOI: 10.1007/s10858-021-00367-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Accepted: 04/02/2021] [Indexed: 06/12/2023]
Abstract
Spectral editing is crucial to simplify the crowded solid-state NMR spectra of proteins. New techniques are introduced to edit 13C-13C correlations of uniformly labeled proteins under moderate magic-angle spinning (MAS), based on our recent frequency-selective homonuclear recoupling sequences [Zhang et al., J. Phys. Chem. Lett. 2020, 11, 8077-8083]. The signals of alanine, serine, or threonine residues are selected out by selective 13Cα-13Cβ double-quantum filtering (DQF). The 13Cα-13Cβ correlations of alanine residues are selectively established with efficiency up to ~ 1.8 times that by dipolar-assisted rotational resonance (DARR). The techniques are shown in 2D/3D NCCX experiments and applied to the uniformly 13C, 15N labeled Aquaporin Z (AqpZ) membrane protein, demonstrating their potential to simplify spectral analyses in biological solid-state NMR.
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Affiliation(s)
- Hang Xiao
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Innovation Academy for Precision Measurement Science and Technology, National Center for Magnetic Resonance in Wuhan, Key Laboratory of Magnetic Resonance in Biological Systems, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan, 430071, P. R. China
- University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Zhengfeng Zhang
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Innovation Academy for Precision Measurement Science and Technology, National Center for Magnetic Resonance in Wuhan, Key Laboratory of Magnetic Resonance in Biological Systems, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan, 430071, P. R. China.
- University of Chinese Academy of Sciences, Beijing, 100049, P. R. China.
| | - Yongxiang Zhao
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Innovation Academy for Precision Measurement Science and Technology, National Center for Magnetic Resonance in Wuhan, Key Laboratory of Magnetic Resonance in Biological Systems, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan, 430071, P. R. China
| | - Jun Yang
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Innovation Academy for Precision Measurement Science and Technology, National Center for Magnetic Resonance in Wuhan, Key Laboratory of Magnetic Resonance in Biological Systems, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan, 430071, P. R. China.
- Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, 430074, P. R. China.
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66
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Fritzsching KJ, Keeler EG, He C, McDermott AE. Scaled recoupling of chemical shift anisotropies at high magnetic fields under MAS with interspersed C-elements. J Chem Phys 2021; 153:104201. [PMID: 32933302 DOI: 10.1063/5.0020682] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The power of chemical shift anisotropy (CSA) measurements for probing structure and dynamics of molecules has been long recognized. NMR pulse sequences that allow measurement of CSA values in an indirect dimension of a protein correlation spectrum have been employed for aliphatic groups, but for practical reasons, carbonyl functional groups have been little studied, despite the fact that carbonyls are expected to give particularly varied and informative CSA values. Specifically, the wide spectral widths of carbonyl tensors make their measurements difficult with typically attainable spectrometer settings. We present here an extended family of experiments that enable the recovery of static CSA lineshapes in an indirect dimension of magic angle spinning (MAS) solid-state NMR experiments, except for various real valued scaling factors. The experiment is suitable for uniformly labeled material, at moderate MAS rates (10 kHz-30 kHz) and at higher magnetic fields (ν0H > 600 MHz). Specifically, the experiments are based on pulse sequence elements from a previous commonly used pulse sequence for CSA measurement, recoupling of chemical shift anisotropy (ROCSA), while modification of scaling factors is achieved by interspersing different blocks of C-elements of the same Cnn 1 cycle. Using experimental conditions similar to the parent ROCSA sequence, a CSA scaling factor between 0 and 0.272 can be obtained, thus allowing a useful practical range of possibilities in experimental conditions for measurement of larger CSA values. Using these blocks, it is also possible to make a constant-time CSA recoupling sequence. The effectiveness of this approach, fROCSA, is shown on model compounds 1-13C-Gly, U-13C,15N-l-His, and microcrystalline U-13C,15N-Ubiquitin.
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Affiliation(s)
| | - Eric G Keeler
- Department of Chemistry, Columbia University, New York, New York 10027, USA
| | - Chengming He
- Department of Chemistry, Columbia University, New York, New York 10027, USA
| | - Ann E McDermott
- Department of Chemistry, Columbia University, New York, New York 10027, USA
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67
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Pérez-Conesa S, Keeler EG, Zhang D, Delemotte L, McDermott AE. Informing NMR experiments with molecular dynamics simulations to characterize the dominant activated state of the KcsA ion channel. J Chem Phys 2021; 154:165102. [PMID: 33940802 PMCID: PMC9250420 DOI: 10.1063/5.0040649] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
As the first potassium channel with an x-ray structure determined, and given its homology to eukaryotic channels, the pH-gated prokaryotic channel KcsA has been extensively studied. Nevertheless, questions related, in particular, to the allosteric coupling between its gates remain open. The many currently available x-ray crystallography structures appear to correspond to various stages of activation and inactivation, offering insights into the molecular basis of these mechanisms. Since these studies have required mutations, complexation with antibodies, and substitution of detergents in place of lipids, examining the channel under more native conditions is desirable. Solid-state nuclear magnetic resonance (SSNMR) can be used to study the wild-type protein under activating conditions (low pH), at room temperature, and in bacteriomimetic liposomes. In this work, we sought to structurally assign the activated state present in SSNMR experiments. We used a combination of molecular dynamics (MD) simulations, chemical shift prediction algorithms, and Bayesian inference techniques to determine which of the most plausible x-ray structures resolved to date best represents the activated state captured in SSNMR. We first identified specific nuclei with simulated NMR chemical shifts that differed significantly when comparing partially open vs fully open ensembles from MD simulations. The simulated NMR chemical shifts for those specific nuclei were then compared to experimental ones, revealing that the simulation of the partially open state was in good agreement with the SSNMR data. Nuclei that discriminate effectively between partially and fully open states belong to residues spread over the sequence and provide a molecular level description of the conformational change.
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Affiliation(s)
- Sergio Pérez-Conesa
- KTH Royal Institute of Technology, Science for Life Laboratory, Stockholm, Sweden
| | - Eric G Keeler
- Department of Chemistry, Columbia University, New York, New York 10027, USA
| | - Dongyu Zhang
- Department of Chemistry, Columbia University, New York, New York 10027, USA
| | - Lucie Delemotte
- KTH Royal Institute of Technology, Science for Life Laboratory, Stockholm, Sweden
| | - Ann E McDermott
- Department of Chemistry, Columbia University, New York, New York 10027, USA
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68
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Fonda BD, Jami KM, Boulos NR, Murray DT. Identification of the Rigid Core for Aged Liquid Droplets of an RNA-Binding Protein Low Complexity Domain. J Am Chem Soc 2021; 143:6657-6668. [PMID: 33896178 DOI: 10.1021/jacs.1c02424] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The biomolecular condensation of proteins with low complexity sequences plays a functional role in RNA metabolism and a pathogenic role in neurodegenerative diseases. The formation of dynamic liquid droplets brings biomolecules together to achieve complex cellular functions. The rigidification of liquid droplets into β-strand-rich hydrogel structures composed of protein fibrils is thought to be purely pathological in nature. However, low complexity sequences often harbor multiple fibril-prone regions with delicately balanced functional and pathological interactions. Here, we investigate the maturation of liquid droplets formed by the low complexity domain of the TAR DNA-binding protein 43 (TDP-43). Solid state nuclear magnetic resonance measurements on the aged liquid droplets identify residues 365-400 as the structured core, which are squarely outside the region between residues 311-360 thought to be most important for pathological fibril formation and aggregation. The results of this study suggest that multiple segments of this low complexity domain are prone to form fibrils and that stabilization of β-strand-rich structure in one segment precludes the other region from adopting a rigid fibril structure.
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Affiliation(s)
- Blake D Fonda
- Department of Chemistry, University of California, Davis, California 95616, United States
| | - Khaled M Jami
- Department of Chemistry, University of California, Davis, California 95616, United States
| | - Natalie R Boulos
- Department of Chemistry, University of California, Davis, California 95616, United States
| | - Dylan T Murray
- Department of Chemistry, University of California, Davis, California 95616, United States
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69
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Pradhan T, Annamalai K, Sarkar R, Hegenbart U, Schönland S, Fändrich M, Reif B. Solid state NMR assignments of a human λ-III immunoglobulin light chain amyloid fibril. BIOMOLECULAR NMR ASSIGNMENTS 2021; 15:9-16. [PMID: 32946005 PMCID: PMC7973639 DOI: 10.1007/s12104-020-09975-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 09/11/2020] [Indexed: 05/09/2023]
Abstract
The aggregation of antibody light chains is linked to systemic light chain (AL) amyloidosis, a disease where amyloid deposits frequently affect the heart and the kidney. We here investigate fibrils from the λ-III FOR005 light chain (LC), which is derived from an AL-patient with severe cardiac involvement. In FOR005, five residues are mutated with respect to its closest germline gene segment IGLV3-19 and IGLJ3. All mutations are located close to the complementarity determining regions (CDRs). The sequence segments responsible for the fibril formation are not yet known. We use fibrils extracted from the heart of this particular amyloidosis patient as seeds to prepare fibrils for solid-state NMR. We show that the seeds induce the formation of a specific fibril structure from the biochemically produced protein. We have assigned the fibril core region of the FOR005-derived fibrils and characterized the secondary structure propensity of the observed amino acids. As the primary structure of the aggregated patient protein is different for every AL patient, it is important to study, analyze and report a greater number of light chain sequences associated with AL amyloidosis.
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Affiliation(s)
- Tejaswini Pradhan
- Helmholtz-Zentrum München (HMGU), Deutsches Forschungszentrum für Gesundheit Und Umwelt, Institute of Structural Biology, Ingolstädter Landstr. 1, 85764, Neuherberg, Germany
- Department of Chemistry, Munich Center for Integrated Protein Science (CIPS-M), Technische Universität München (TUM), Lichtenbergstr. 4, 85747, Garching, Germany
| | - Karthikeyan Annamalai
- Institute of Protein Biochemistry, Ulm University, Helmholtzstrasse 8/1, 89081, Ulm, Germany
| | - Riddhiman Sarkar
- Helmholtz-Zentrum München (HMGU), Deutsches Forschungszentrum für Gesundheit Und Umwelt, Institute of Structural Biology, Ingolstädter Landstr. 1, 85764, Neuherberg, Germany
- Department of Chemistry, Munich Center for Integrated Protein Science (CIPS-M), Technische Universität München (TUM), Lichtenbergstr. 4, 85747, Garching, Germany
| | - Ute Hegenbart
- Medical Department V, Amyloidosis Center, Heidelberg University Hospital, 69120, Heidelberg, Germany
| | - Stefan Schönland
- Medical Department V, Amyloidosis Center, Heidelberg University Hospital, 69120, Heidelberg, Germany
| | - Marcus Fändrich
- Institute of Protein Biochemistry, Ulm University, Helmholtzstrasse 8/1, 89081, Ulm, Germany
| | - Bernd Reif
- Helmholtz-Zentrum München (HMGU), Deutsches Forschungszentrum für Gesundheit Und Umwelt, Institute of Structural Biology, Ingolstädter Landstr. 1, 85764, Neuherberg, Germany.
- Department of Chemistry, Munich Center for Integrated Protein Science (CIPS-M), Technische Universität München (TUM), Lichtenbergstr. 4, 85747, Garching, Germany.
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70
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Wu XL, Hu H, Dong XQ, Zhang J, Wang J, Schwieters CD, Liu J, Wu GX, Li B, Lin JY, Wang HY, Lu JX. The amyloid structure of mouse RIPK3 (receptor interacting protein kinase 3) in cell necroptosis. Nat Commun 2021; 12:1627. [PMID: 33712586 PMCID: PMC7955032 DOI: 10.1038/s41467-021-21881-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 02/15/2021] [Indexed: 12/24/2022] Open
Abstract
RIPK3 amyloid complex plays crucial roles during TNF-induced necroptosis and in response to immune defense in both human and mouse. Here, we have structurally characterized mouse RIPK3 homogeneous self-assembly using solid-state NMR, revealing a well-ordered N-shaped amyloid core structure featured with 3 parallel in-register β-sheets. This structure differs from previously published human RIPK1/RIPK3 hetero-amyloid complex structure, which adopted a serpentine fold. Functional studies indicate both RIPK1-RIPK3 binding and RIPK3 amyloid formation are essential but not sufficient for TNF-induced necroptosis. The structural integrity of RIPK3 fibril with three β-strands is necessary for signaling. Molecular dynamics simulations with a mouse RIPK1/RIPK3 model indicate that the hetero-amyloid is less stable when adopting the RIPK3 fibril conformation, suggesting a structural transformation of RIPK3 from RIPK1-RIPK3 binding to RIPK3 amyloid formation. This structural transformation would provide the missing link connecting RIPK1-RIPK3 binding to RIPK3 homo-oligomer formation in the signal transduction. Receptor Interacting Protein Kinase 3 (RIPK3) has a key role in TNF-induced necroptosis. Here, the authors combine solid state NMR measurements, MD simulations and cell based assays to characterize mouse RIPK3 and they present the structure of the RIPK3 amyloid core.
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Affiliation(s)
- Xia-Lian Wu
- School of Life Science and Technology, ShanghaiTech University, Shanghai, PR China.,CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai, PR China.,University of Chinese Academy of Sciences, Beijing, PR China
| | - Hong Hu
- School of Life Science and Technology, ShanghaiTech University, Shanghai, PR China.,CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai, PR China.,University of Chinese Academy of Sciences, Beijing, PR China
| | - Xing-Qi Dong
- School of Life Science and Technology, ShanghaiTech University, Shanghai, PR China.,CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai, PR China.,University of Chinese Academy of Sciences, Beijing, PR China
| | - Jing Zhang
- School of Life Science and Technology, ShanghaiTech University, Shanghai, PR China.,CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai, PR China.,University of Chinese Academy of Sciences, Beijing, PR China
| | - Jian Wang
- School of Life Science and Technology, ShanghaiTech University, Shanghai, PR China
| | - Charles D Schwieters
- Laboratory of Imaging Sciences, Office of Intramural Research, Center for Information Technology, National Institutes of Health, Bethesda, MD, USA
| | - Jing Liu
- School of Life Science and Technology, ShanghaiTech University, Shanghai, PR China.,CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai, PR China.,University of Chinese Academy of Sciences, Beijing, PR China
| | - Guo-Xiang Wu
- School of Life Science and Technology, ShanghaiTech University, Shanghai, PR China.,CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai, PR China.,University of Chinese Academy of Sciences, Beijing, PR China
| | - Bing Li
- School of Life Science and Technology, ShanghaiTech University, Shanghai, PR China
| | - Jing-Yu Lin
- School of Life Science and Technology, ShanghaiTech University, Shanghai, PR China.,CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai, PR China.,University of Chinese Academy of Sciences, Beijing, PR China
| | - Hua-Yi Wang
- School of Life Science and Technology, ShanghaiTech University, Shanghai, PR China.
| | - Jun-Xia Lu
- School of Life Science and Technology, ShanghaiTech University, Shanghai, PR China.
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71
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Structure of membrane diacylglycerol kinase in lipid bilayers. Commun Biol 2021; 4:282. [PMID: 33674677 PMCID: PMC7935881 DOI: 10.1038/s42003-021-01802-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 02/05/2021] [Indexed: 12/17/2022] Open
Abstract
Diacylglycerol kinase (DgkA) is a small integral membrane protein, responsible for the ATP-dependent phosphorylation of diacylglycerol to phosphatidic acid. Its structures reported in previous studies, determined in detergent micelles by solution NMR and in monoolein cubic phase by X-ray crystallography, differ significantly. These differences point to the need to validate these detergent-based structures in phospholipid bilayers. Here, we present a well-defined homo-trimeric structure of DgkA in phospholipid bilayers determined by magic angle spinning solid-state NMR (ssNMR) spectroscopy, using an approach combining intra-, inter-molecular paramagnetic relaxation enhancement (PRE)-derived distance restraints and CS-Rosetta calculations. The DgkA structure determined in lipid bilayers is different from the solution NMR structure. In addition, although ssNMR structure of DgkA shows a global folding similar to that determined by X-ray, these two structures differ in monomeric symmetry and dynamics. A comparative analysis of DgkA structures determined in three different detergent/lipid environments provides a meaningful demonstration of the influence of membrane mimetic environments on the structure and dynamics of membrane proteins. Jianping Li et al. present the homo-trimeric structure of the small integral membrane protein diacylglycerol kinase (DgkA) in phospholipid bilayers determined by magic angle spinning solid-state NMR spectroscopy. They compare the structure with structures solved by solution NMR and X-ray crystallography and provide insights into the influence of membrane mimetic environments on membrane proteins.
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72
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Structural details of amyloid β oligomers in complex with human prion protein as revealed by solid-state MAS NMR spectroscopy. J Biol Chem 2021; 296:100499. [PMID: 33667547 PMCID: PMC8042448 DOI: 10.1016/j.jbc.2021.100499] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 02/24/2021] [Accepted: 03/01/2021] [Indexed: 02/06/2023] Open
Abstract
Human PrP (huPrP) is a high-affinity receptor for oligomeric amyloid β (Aβ) protein aggregates. Binding of Aβ oligomers to membrane-anchored huPrP has been suggested to trigger neurotoxic cell signaling in Alzheimer’s disease, while an N-terminal soluble fragment of huPrP can sequester Aβ oligomers and reduce their toxicity. Synthetic oligomeric Aβ species are known to be heterogeneous, dynamic, and transient, rendering their structural investigation particularly challenging. Here, using huPrP to preserve Aβ oligomers by coprecipitating them into large heteroassemblies, we investigated the conformations of Aβ(1–42) oligomers and huPrP in the complex by solid-state MAS NMR spectroscopy. The disordered N-terminal region of huPrP becomes immobilized in the complex and therefore visible in dipolar spectra without adopting chemical shifts characteristic of a regular secondary structure. Most of the well-defined C-terminal part of huPrP is part of the rigid complex, and solid-state NMR spectra suggest a loss in regular secondary structure in the two C-terminal α-helices. For Aβ(1–42) oligomers in complex with huPrP, secondary chemical shifts reveal substantial β-strand content. Importantly, not all Aβ(1–42) molecules within the complex have identical conformations. Comparison with the chemical shifts of synthetic Aβ fibrils suggests that the Aβ oligomer preparation represents a heterogeneous mixture of β-strand-rich assemblies, of which some have the potential to evolve and elongate into different fibril polymorphs, reflecting a general propensity of Aβ to adopt variable β-strand-rich conformers. Taken together, our results reveal structural changes in huPrP upon binding to Aβ oligomers that suggest a role of the C terminus of huPrP in cell signaling. Trapping Aβ(1–42) oligomers by binding to huPrP has proved to be a useful tool for studying the structure of these highly heterogeneous β-strand-rich assemblies.
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73
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Reif B, Ashbrook SE, Emsley L, Hong M. Solid-state NMR spectroscopy. NATURE REVIEWS. METHODS PRIMERS 2021; 1:2. [PMID: 34368784 PMCID: PMC8341432 DOI: 10.1038/s43586-020-00002-1] [Citation(s) in RCA: 155] [Impact Index Per Article: 51.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 10/29/2020] [Indexed: 12/18/2022]
Abstract
Solid-state nuclear magnetic resonance (NMR) spectroscopy is an atomic-level method used to determine the chemical structure, three-dimensional structure, and dynamics of solids and semi-solids. This Primer summarizes the basic principles of NMR as applied to the wide range of solid systems. The fundamental nuclear spin interactions and the effects of magnetic fields and radiofrequency pulses on nuclear spins are the same as in liquid-state NMR. However, because of the anisotropy of the interactions in the solid state, the majority of high-resolution solid-state NMR spectra is measured under magic-angle spinning (MAS), which has profound effects on the types of radiofrequency pulse sequences required to extract structural and dynamical information. We describe the most common MAS NMR experiments and data analysis approaches for investigating biological macromolecules, organic materials, and inorganic solids. Continuing development of sensitivity-enhancement approaches, including 1H-detected fast MAS experiments, dynamic nuclear polarization, and experiments tailored to ultrahigh magnetic fields, is described. We highlight recent applications of solid-state NMR to biological and materials chemistry. The Primer ends with a discussion of current limitations of NMR to study solids, and points to future avenues of development to further enhance the capabilities of this sophisticated spectroscopy for new applications.
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Affiliation(s)
- Bernd Reif
- Technische Universität München, Department Chemie, Lichtenbergstr. 4, D-85747 Garching, Germany
| | - Sharon E. Ashbrook
- School of Chemistry, University of St Andrews, North Haugh, St Andrews, KY16 9ST, UK
| | - Lyndon Emsley
- École Polytechnique Fédérale de Lausanne (EPFL), Institut des sciences et ingénierie chimiques, CH-1015 Lausanne, Switzerland
| | - Mei Hong
- Department of Chemistry and Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, 170 Albany Street, Cambridge, MA 02139
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74
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Structure and dynamics of the drug-bound bacterial transporter EmrE in lipid bilayers. Nat Commun 2021; 12:172. [PMID: 33420032 PMCID: PMC7794478 DOI: 10.1038/s41467-020-20468-7] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 12/01/2020] [Indexed: 01/29/2023] Open
Abstract
The dimeric transporter, EmrE, effluxes polyaromatic cationic drugs in a proton-coupled manner to confer multidrug resistance in bacteria. Although the protein is known to adopt an antiparallel asymmetric topology, its high-resolution drug-bound structure is so far unknown, limiting our understanding of the molecular basis of promiscuous transport. Here we report an experimental structure of drug-bound EmrE in phospholipid bilayers, determined using 19F and 1H solid-state NMR and a fluorinated substrate, tetra(4-fluorophenyl) phosphonium (F4-TPP+). The drug-binding site, constrained by 214 protein-substrate distances, is dominated by aromatic residues such as W63 and Y60, but is sufficiently spacious for the tetrahedral drug to reorient at physiological temperature. F4-TPP+ lies closer to the proton-binding residue E14 in subunit A than in subunit B, explaining the asymmetric protonation of the protein. The structure gives insight into the molecular mechanism of multidrug recognition by EmrE and establishes the basis for future design of substrate inhibitors to combat antibiotic resistance.
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75
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Pradhan T, Annamalai K, Sarkar R, Huhn S, Hegenbart U, Schönland S, Fändrich M, Reif B. Seeded fibrils of the germline variant of human λ-III immunoglobulin light chain FOR005 have a similar core as patient fibrils with reduced stability. J Biol Chem 2020; 295:18474-18484. [PMID: 33093170 PMCID: PMC7939468 DOI: 10.1074/jbc.ra120.016006] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 10/21/2020] [Indexed: 11/26/2022] Open
Abstract
Systemic antibody light chains (AL) amyloidosis is characterized by deposition of amyloid fibrils derived from a particular antibody light chain. Cardiac involvement is a major risk factor for mortality. Using MAS solid-state NMR, we studied the fibril structure of a recombinant light chain fragment corresponding to the fibril protein from patient FOR005, together with fibrils formed by protein sequence variants that are derived from the closest germline (GL) sequence. Both analyzed fibril structures were seeded with ex-vivo amyloid fibrils purified from the explanted heart of this patient. We find that residues 11-42 and 69-102 adopt β-sheet conformation in patient protein fibrils. We identify arginine-49 as a key residue that forms a salt bridge to aspartate-25 in the patient protein fibril structure. In the germline sequence, this residue is replaced by a glycine. Fibrils from the GL protein and from the patient protein harboring the single point mutation R49G can be both heterologously seeded using patient ex-vivo fibrils. Seeded R49G fibrils show an increased heterogeneity in the C-terminal residues 80-102, which is reflected by the disappearance of all resonances of these residues. By contrast, residues 11-42 and 69-77, which are visible in the MAS solid-state NMR spectra, show 13Cα chemical shifts that are highly like patient fibrils. The mutation R49G thus induces a conformational heterogeneity at the C terminus in the fibril state, whereas the overall fibril topology is retained. These findings imply that patient mutations in FOR005 can stabilize the fibril structure.
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Affiliation(s)
- Tejaswini Pradhan
- Helmholtz-Zentrum München (HMGU), Deutsches Forschungszentrum für Gesundheit und UmweltInstitute of Structural Biology (STB), Neuherberg, Germany; Munich Center for Integrated Protein Science (CIPS-M) at the Dept. of Chemistry, Technische Universität München (TUM), Garching, Germany
| | | | - Riddhiman Sarkar
- Helmholtz-Zentrum München (HMGU), Deutsches Forschungszentrum für Gesundheit und UmweltInstitute of Structural Biology (STB), Neuherberg, Germany; Munich Center for Integrated Protein Science (CIPS-M) at the Dept. of Chemistry, Technische Universität München (TUM), Garching, Germany
| | - Stefanie Huhn
- Medical Department V, Multiple Myeloma Center, Heidelberg University Hospital, Heidelberg, Germany
| | - Ute Hegenbart
- Medical Department V, Amyloidosis Center, Heidelberg University Hospital, Heidelberg, Germany
| | - Stefan Schönland
- Medical Department V, Amyloidosis Center, Heidelberg University Hospital, Heidelberg, Germany
| | - Marcus Fändrich
- Institute of Protein Biochemistry, Ulm University, Ulm, Germany
| | - Bernd Reif
- Helmholtz-Zentrum München (HMGU), Deutsches Forschungszentrum für Gesundheit und UmweltInstitute of Structural Biology (STB), Neuherberg, Germany; Munich Center for Integrated Protein Science (CIPS-M) at the Dept. of Chemistry, Technische Universität München (TUM), Garching, Germany.
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76
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Lacabanne D, Boudet J, Malär AA, Wu P, Cadalbert R, Salmon L, Allain FHT, Meier BH, Wiegand T. Protein Side-Chain-DNA Contacts Probed by Fast Magic-Angle Spinning NMR. J Phys Chem B 2020; 124:11089-11097. [PMID: 33238710 PMCID: PMC7734624 DOI: 10.1021/acs.jpcb.0c08150] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
![]()
Protein–nucleic
acid interactions are essential in a variety
of biological events ranging from the replication of genomic DNA to
the synthesis of proteins. Noncovalent interactions guide such molecular
recognition events, and protons are often at the center of them, particularly
due to their capability of forming hydrogen bonds to the nucleic acid
phosphate groups. Fast magic-angle spinning experiments (100 kHz)
reduce the proton NMR line width in solid-state NMR of fully protonated
protein–DNA complexes to such an extent that resolved proton
signals from side-chains coordinating the DNA can be detected. We
describe a set of NMR experiments focusing on the detection of protein
side-chains from lysine, arginine, and aromatic amino acids and discuss
the conclusions that can be obtained on their role in DNA coordination.
We studied the 39 kDa enzyme of the archaeal pRN1 primase complexed
with DNA and characterize protein–DNA contacts in the presence
and absence of bound ATP molecules.
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Affiliation(s)
| | - Julien Boudet
- Institute of Molecular Biology and Biophysics, ETH Zurich, 8093 Zurich, Switzerland
| | | | - Pengzhi Wu
- Institute of Molecular Biology and Biophysics, ETH Zurich, 8093 Zurich, Switzerland.,Institute of Biochemistry, ETH Zurich, 8093 Zurich, Switzerland
| | | | - Loic Salmon
- Institute of Molecular Biology and Biophysics, ETH Zurich, 8093 Zurich, Switzerland
| | - Frédéric H-T Allain
- Institute of Molecular Biology and Biophysics, ETH Zurich, 8093 Zurich, Switzerland.,Institute of Biochemistry, ETH Zurich, 8093 Zurich, Switzerland
| | - Beat H Meier
- Physical Chemistry, ETH Zurich, 8093 Zurich, Switzerland
| | - Thomas Wiegand
- Physical Chemistry, ETH Zurich, 8093 Zurich, Switzerland
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77
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Conformational Dynamics of Light-Harvesting Complex II in a Native Membrane Environment. Biophys J 2020; 120:270-283. [PMID: 33285116 DOI: 10.1016/j.bpj.2020.11.2265] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 11/17/2020] [Accepted: 11/24/2020] [Indexed: 12/14/2022] Open
Abstract
Photosynthetic light-harvesting complexes (LHCs) of higher plants, moss, and green algae can undergo dynamic conformational transitions, which have been correlated to their ability to adapt to fluctuations in the light environment. Herein, we demonstrate the application of solid-state NMR spectroscopy on native, heterogeneous thylakoid membranes of Chlamydomonas reinhardtii (Cr) and on Cr light-harvesting complex II (LHCII) in thylakoid lipid bilayers to detect LHCII conformational dynamics in its native membrane environment. We show that membrane-reconstituted LHCII contains selective sites that undergo fast, large-amplitude motions, including the phytol tails of two chlorophylls. Protein plasticity is also observed in the N-terminal stromal loop and in protein fragments facing the lumen, involving sites that stabilize the xanthophyll-cycle carotenoid violaxanthin and the two luteins. The results report on the intrinsic flexibility of LHCII pigment-protein complexes in a membrane environment, revealing putative sites for conformational switching. In thylakoid membranes, fast dynamics of protein and pigment sites is significantly reduced, which suggests that in their native organelle membranes, LHCII complexes are locked in specific conformational states.
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78
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Mandala VS, McKay MJ, Shcherbakov AA, Dregni AJ, Kolocouris A, Hong M. Structure and drug binding of the SARS-CoV-2 envelope protein transmembrane domain in lipid bilayers. Nat Struct Mol Biol 2020; 27:1202-1208. [PMID: 33177698 PMCID: PMC7718435 DOI: 10.1038/s41594-020-00536-8] [Citation(s) in RCA: 240] [Impact Index Per Article: 60.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Accepted: 10/28/2020] [Indexed: 12/19/2022]
Abstract
An essential protein of the SARS-CoV-2 virus, the envelope protein E, forms a homopentameric cation channel that is important for virus pathogenicity. Here we report a 2.1-Å structure and the drug-binding site of E's transmembrane domain (ETM), determined using solid-state NMR spectroscopy. In lipid bilayers that mimic the endoplasmic reticulum-Golgi intermediate compartment (ERGIC) membrane, ETM forms a five-helix bundle surrounding a narrow pore. The protein deviates from the ideal α-helical geometry due to three phenylalanine residues, which stack within each helix and between helices. Together with valine and leucine interdigitation, these cause a dehydrated pore compared with the viroporins of influenza viruses and HIV. Hexamethylene amiloride binds the polar amino-terminal lumen, whereas acidic pH affects the carboxy-terminal conformation. Thus, the N- and C-terminal halves of this bipartite channel may interact with other viral and host proteins semi-independently. The structure sets the stage for designing E inhibitors as antiviral drugs.
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Affiliation(s)
- Venkata S Mandala
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Matthew J McKay
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA, USA
| | | | - Aurelio J Dregni
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Antonios Kolocouris
- Department of Pharmaceutical Chemistry, National and Kapodistrian University of Athens, Panepistimioupolis Zografou, Athens, Greece
| | - Mei Hong
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA, USA.
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79
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Ehren HL, Appels FV, Houben K, Renault MA, Wösten HA, Baldus M. Characterization of the cell wall of a mushroom forming fungus at atomic resolution using solid-state NMR spectroscopy. Cell Surf 2020; 6:100046. [PMID: 33204900 PMCID: PMC7649524 DOI: 10.1016/j.tcsw.2020.100046] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 10/16/2020] [Accepted: 10/21/2020] [Indexed: 01/18/2023] Open
Abstract
Cell walls are essential in the interaction of fungi with the (a)biotic environment and are also key to hyphal morphogenesis and mechanical strength. Here, we used solid-state NMR (ssNMR) spectroscopy combined with HPLC and GC-MS to study the structural organization of the cell wall of a representative of the Basidiomycota, one of the two main phyla of fungi. Based on the data we propose a refined model for the cell wall of a basidiomycete. In this model, the rigid core is built from α- and β-(1,3)-glucan, β-(1,3)-(1,6)-glucan, highly branched and single stranded β-(1,4)-chitin as well as polymeric fucose. The mobile fraction of the cell wall is composed of β-(1,3)-glucan, β-(1,3)-(1,6)-glucan, β-(1,6)-glucan, α-linked reducing and non-reducing ends and polymeric mannose. Together, these findings provide novel insights into the structural organization of the cell wall of the model basidiomycete S. commune that was previously based on destructive chemical and enzymatic analysis.
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Affiliation(s)
- Helena Leona Ehren
- NMR Spectroscopy, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, 3584 CH Utrecht, the Netherlands
| | - Freek V.W. Appels
- Microbiology, Department of Biology, Utrecht University, Padualaan 8, 3584 CH Utrecht, the Netherlands
| | - Klaartje Houben
- NMR Spectroscopy, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, 3584 CH Utrecht, the Netherlands
| | - Marie A.M. Renault
- NMR Spectroscopy, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, 3584 CH Utrecht, the Netherlands
| | - Han A.B. Wösten
- Microbiology, Department of Biology, Utrecht University, Padualaan 8, 3584 CH Utrecht, the Netherlands
| | - Marc Baldus
- NMR Spectroscopy, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, 3584 CH Utrecht, the Netherlands
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80
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Miao Y, Lam D, Zhuang J, Zhu J, Poget SF, Tang M. Membrane Topology of an Ion Channel Detected by Solid-State Nuclear Magnetic Resonance and Paramagnetic Effects. J Phys Chem Lett 2020; 11:9795-9801. [PMID: 33151058 DOI: 10.1021/acs.jpclett.0c02014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Ion channels are often targeted by toxins or other ligands to modify their channel activities and alter ion conductance. Interactions between toxins and ion channels could result in changes in membrane insertion depth for residues close to the binding site. Paramagnetic solid-state nuclear magnetic resonance (SSNMR) has shown great potential in providing structural information on membrane samples. We used KcsA as a model ion channel to investigate how the paramagnetic effects of Mn2+ and Dy3+ ions with headgroup-modified chelator lipids would influence the SSNMR signals of membrane proteins in proteoliposomes. Spectral comparisons have shown significant changes of peak intensities for the residues in the loop or terminal regions due to paramagnetic effects corresponding to the close proximity to the membrane surface. Hence, these results demonstrate that paramagnetic SSNMR can be used to detect surface residues based on the topology and membrane insertion properties for integral membrane proteins.
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Affiliation(s)
- Yimin Miao
- Department of Chemistry, College of Staten Island-Ph.D. Programs in Chemistry and Biochemistry, The Graduate Center of the City University of New York, New York, New York 10016, United States
| | - Dennis Lam
- Department of Chemistry, College of Staten Island-Ph.D. Programs in Chemistry and Biochemistry, The Graduate Center of the City University of New York, New York, New York 10016, United States
| | - Jianqin Zhuang
- Department of Chemistry, College of Staten Island-Ph.D. Programs in Chemistry and Biochemistry, The Graduate Center of the City University of New York, New York, New York 10016, United States
| | - Jing Zhu
- Department of Chemistry, College of Staten Island-Ph.D. Programs in Chemistry and Biochemistry, The Graduate Center of the City University of New York, New York, New York 10016, United States
| | - Sebastien F Poget
- Department of Chemistry, College of Staten Island-Ph.D. Programs in Chemistry and Biochemistry, The Graduate Center of the City University of New York, New York, New York 10016, United States
| | - Ming Tang
- Department of Chemistry, College of Staten Island-Ph.D. Programs in Chemistry and Biochemistry, The Graduate Center of the City University of New York, New York, New York 10016, United States
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81
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Djajamuliadi J, Ohgo K, Kumashiro KK. A Two-State Model Describes the Temperature-Dependent Conformational Equilibrium in the Alanine-Rich Domains in Elastin. J Phys Chem B 2020; 124:9017-9028. [PMID: 32936634 DOI: 10.1021/acs.jpcb.0c06811] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Elastin is the insoluble elastomeric protein that provides extensibility and resilience to vertebrate tissues. Limited high-resolution structural data for elastin are notably complex. To access this information, this protein is considered in the simplified context of its two general domain types, that is, hydrophobic (HP) and crosslinking (CL). The question of elastin's structure-function has directed the focus of nearly all previous studies in the literature to the unique repeating sequences characteristic of this protein, found primarily in the HP domains. The CL domains were assumed to play a very limited role in biological elasticity due in part to the significant α-helical character that was (incorrectly) predicted for these regions. In this study, the conformational heterogeneity of alanines in native elastin's CL domains is examined in the context of helix-coil transition theory (HCTT) using solid-state nuclear magnetic resonance (SSNMR) spectroscopy in tandem with strategic isotopic labeling. Helix and coil populations are observed at all temperatures, but the former increases significantly at lower temperatures. Below the glass transition temperature (Tg), two major populations of alanines in the CL regions are resolved by two-dimensional SSNMR; one-dimensional methods are used for characterization in nativelike conditions. The spectra of 13CO-Ala in the CL regions are simulated using an HCTT-based statistical mechanical representation. Below Tg, longer segments with significant helical probabilities are consistent with the experimental data. At higher temperatures, the SSNMR lineshapes are best fit with a distribution of shorter (Ala)n segments, most in random coil. These results are used to refine a structure-function model for elastin in the context of HCTT, redirecting attention to the CL domains and their role in elasticity.
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Affiliation(s)
- Jhonsen Djajamuliadi
- Department of Chemistry, University of Hawaii, 2545 McCarthy Mall, Honolulu, Hawaii 96822, United States
| | - Kosuke Ohgo
- Department of Chemistry, University of Hawaii, 2545 McCarthy Mall, Honolulu, Hawaii 96822, United States
| | - Kristin K Kumashiro
- Department of Chemistry, University of Hawaii, 2545 McCarthy Mall, Honolulu, Hawaii 96822, United States
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82
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Bousset L, Luckgei N, Kabani M, Gardiennet C, Schütz AK, Melki R, Meier BH, Böckmann A. Prion Amyloid Polymorphs - The Tag Might Change It All. Front Mol Biosci 2020; 7:190. [PMID: 32850974 PMCID: PMC7423878 DOI: 10.3389/fmolb.2020.00190] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 07/20/2020] [Indexed: 11/13/2022] Open
Abstract
Sup35p is a protein from Saccharomyces cerevisiae. It can propagate using a prion-like mechanism, which means that it can recruit non-prion soluble Sup35p into insoluble fibrils. Sup35p is a large protein showing three distinct domains, N, M and an extended globular domain. We have previously studied the conformations of the full-length and truncated NM versions carrying poly-histidine tags on the N-terminus. Comparison with structural data from C-terminally poly-histidine tagged NM from the literature surprisingly revealed discrepancies. Here we investigated fibrils from the untagged, as well as a C-terminally poly-histidine tagged NM construct, using solid-state NMR. We find that the conformation of untagged NM is very close to the N-terminally tagged NM and confirms our previous findings. The C-terminal poly-histidine tag, in contrast, drastically changes the NM fibril structure, and yields data consistent with results obtained previously on this construct. We conclude that the C-terminally located Sup35p globular domain influences the structure of the fibrillar core at the N domain, as previously shown. We further conclude, based on the present data, that small tags on NM C-terminus have a substantial, despite different, impact. Modifications at this remote localization thus shows an unexpected influence on the fibril structure, and importantly also its propensity to induce [PSI+].
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Affiliation(s)
- Luc Bousset
- Institut Francois Jacob (MIRCen), CEA and Laboratory of Neurodegenerative Diseases, CNRS, Fontenay-aux-Roses, France
| | - Nina Luckgei
- Molecular Microbiology and Structural Biochemistry, UMR 5086 CNRS, Universite de Lyon, Lyon, France
| | - Mehdi Kabani
- Institut Francois Jacob (MIRCen), CEA and Laboratory of Neurodegenerative Diseases, CNRS, Fontenay-aux-Roses, France
| | - Carole Gardiennet
- Molecular Microbiology and Structural Biochemistry, UMR 5086 CNRS, Universite de Lyon, Lyon, France
| | - Anne K Schütz
- ETH Zürich, Laboratory of Physical Chemistry, Zurich, Switzerland
| | - Ronald Melki
- Institut Francois Jacob (MIRCen), CEA and Laboratory of Neurodegenerative Diseases, CNRS, Fontenay-aux-Roses, France
| | - Beat H Meier
- ETH Zürich, Laboratory of Physical Chemistry, Zurich, Switzerland
| | - Anja Böckmann
- Molecular Microbiology and Structural Biochemistry, UMR 5086 CNRS, Universite de Lyon, Lyon, France
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83
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Borcik CG, Versteeg DB, Amani R, Yekefallah M, Khan NH, Wylie BJ. The Lipid Activation Mechanism of a Transmembrane Potassium Channel. J Am Chem Soc 2020; 142:14102-14116. [PMID: 32702990 DOI: 10.1021/jacs.0c01991] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Membrane proteins and lipids coevolved to yield unique coregulatory mechanisms. Inward-rectifier K+ (Kir) channels are often activated by anionic lipids endemic to their native membranes and require accessible water along their K+ conductance pathway. To better understand Kir channel activation, we target multiple mutants of the Kir channel KirBac1.1 via solid-state nuclear magnetic resonance (SSNMR) spectroscopy, potassium efflux assays, and Förster resonance energy transfer (FRET) measurements. In the I131C stability mutant (SM), we observe an open-active channel in the presence of anionic lipids with greater activity upon addition of cardiolipin (CL). The introduction of three R to Q mutations (R49/151/153Q (triple Q mutant, TQ)) renders the protein inactive within the same activating lipid environment. Our SSNMR experiments reveal a stark reduction of lipid-protein interactions in the TQ mutant explaining the dramatic loss of channel activity. Water-edited SSNMR experiments further determined the TQ mutant possesses greater overall solvent exposure in comparison to wild-type but with reduced water accessibility along the ion conduction pathway, consistent with the closed state of the channel. These experiments also suggest water is proximal to the selectivity filter of KirBac1.1 in the open-activated state but that it may not directly enter the selectivity filter. Our findings suggest lipid binding initiates a concerted rotation of the cytoplasmic domain subunits, which is stabilized by multiple intersubunit salt bridges. This action buries ionic side chains away from the bulk water, while allowing water greater access to the K+ conduction pathway. This work highlights universal membrane protein motifs, including lipid-protein interactions, domain rearrangement, and water-mediated diffusion mechanisms.
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Affiliation(s)
- Collin G Borcik
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409, United States
| | - Derek B Versteeg
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409, United States
| | - Reza Amani
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409, United States
| | - Maryam Yekefallah
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409, United States
| | - Nazmul H Khan
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409, United States
| | - Benjamin J Wylie
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409, United States
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84
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Calcium and hydroxyapatite binding site of human vitronectin provides insights to abnormal deposit formation. Proc Natl Acad Sci U S A 2020; 117:18504-18510. [PMID: 32699145 DOI: 10.1073/pnas.2007699117] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The human blood protein vitronectin (Vn) is a major component of the abnormal deposits associated with age-related macular degeneration, Alzheimer's disease, and many other age-related disorders. Its accumulation with lipids and hydroxyapatite (HAP) has been demonstrated, but the precise mechanism for deposit formation remains unknown. Using a combination of solution and solid-state NMR experiments, cosedimentation assays, differential scanning fluorimetry (DSF), and binding energy calculations, we demonstrate that Vn is capable of binding both soluble ionic calcium and crystalline HAP, with high affinity and chemical specificity. Calcium ions bind preferentially at an external site, at the top of the hemopexin-like (HX) domain, with a group of four Asp carboxylate groups. The same external site is also implicated in HAP binding. Moreover, Vn acquires thermal stability upon association with either calcium ions or crystalline HAP. The data point to a mechanism whereby Vn plays an active role in orchestrating calcified deposit formation. They provide a platform for understanding the pathogenesis of macular degeneration and other related degenerative disorders, and the normal functions of Vn, especially those related to bone resorption.
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85
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Zhao X, Tian JJ, Yu H, Bryksa BC, Dupuis JH, Ou X, Qian Z, Song C, Wang S, Yada RY. Insights into the mechanism of membrane fusion induced by the plant defense element, plant-specific insert. J Biol Chem 2020; 295:14548-14562. [PMID: 32651232 DOI: 10.1074/jbc.ra120.014311] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 07/01/2020] [Indexed: 11/06/2022] Open
Abstract
In plants, many natural defense mechanisms include cellular membrane fusion as a way to resist infection by external pathogens. Several plant proteins mediate membrane fusion, but the detailed mechanism by which they promote fusion is less clear. Understanding this process could provide valuable insights into these proteins' physiological functions and guide bioengineering applications (i.e. the design of antimicrobial proteins). The plant-specific insert (PSI) from Solanum tuberosum can help reduce certain pathogen attack via membrane fusion. To gain new insights into the process of PSI-induced membrane fusion, a combined approach of NMR, FRET, and in silico studies was used. Our results indicate that (i) under acidic conditions, the PSI experiences a monomer-dimer equilibrium, and the dimeric PSI induces membrane fusion below a certain critical pH; (ii) after fusion, the PSI resides in a highly dehydrated environment with limited solvent accessibility, suggesting its capability in reducing repulsive dehydration forces between liposomes to facilitate fusion; and (iii) as shown by molecular dynamics simulations, the PSI dimer can bind stably to membrane surfaces and can bridge liposomes in close proximity, a critical step for the membrane fusion. In summary, this study provides new and unique insights into the mechanisms by which the PSI and similar proteins induce membrane fusion.
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Affiliation(s)
- Xiaoli Zhao
- College of Chemistry and Molecular Engineering and Beijing NMR Center, Peking University, Beijing, China
| | - Jenny Jingxin Tian
- Food, Nutrition, and Health Program, Faculty of Land and Food Systems, University of British Columbia, Vancouver, British Columbia, Canada
| | - Hua Yu
- Center for Quantitative Biology, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China; Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
| | - Brian C Bryksa
- Food, Nutrition, and Health Program, Faculty of Land and Food Systems, University of British Columbia, Vancouver, British Columbia, Canada
| | - John H Dupuis
- Food, Nutrition, and Health Program, Faculty of Land and Food Systems, University of British Columbia, Vancouver, British Columbia, Canada
| | - Xiuyuan Ou
- MOH Key Laboratory, Institute of Pathogen Biology, Chinese Academy of Medical Science, Beijing, China
| | - Zhaohui Qian
- MOH Key Laboratory, Institute of Pathogen Biology, Chinese Academy of Medical Science, Beijing, China
| | - Chen Song
- Center for Quantitative Biology, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China; Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China.
| | - Shenlin Wang
- College of Chemistry and Molecular Engineering and Beijing NMR Center, Peking University, Beijing, China; Beijing National Laboratory for Molecular Sciences, Beijing, China.
| | - Rickey Y Yada
- Food, Nutrition, and Health Program, Faculty of Land and Food Systems, University of British Columbia, Vancouver, British Columbia, Canada.
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86
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Kraus J, Gupta R, Lu M, Gronenborn AM, Akke M, Polenova T. Accurate Backbone 13 C and 15 N Chemical Shift Tensors in Galectin-3 Determined by MAS NMR and QM/MM: Details of Structure and Environment Matter. Chemphyschem 2020; 21:1436-1443. [PMID: 32363727 PMCID: PMC8080305 DOI: 10.1002/cphc.202000249] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 04/27/2020] [Indexed: 01/07/2023]
Abstract
Chemical shift tensors obtained from solid-state NMR spectroscopy are very sensitive reporters of structure and dynamics in proteins. While accurate 13 C and 15 N chemical shift tensors are accessible by magic angle spinning (MAS) NMR, their quantum mechanical calculations remain challenging, particularly for 15 N atoms. Here we compare experimentally determined backbone 13 Cα and 15 NH chemical shift tensors by MAS NMR with hybrid quantum mechanics/molecular mechanics/molecular dynamics (MD-QM/MM) calculations for the carbohydrate-binding domain of galectin-3. Excellent agreement between experimental and computed 15 NH chemical shift anisotropy values was obtained using the Amber ff15ipq force field when solvent dynamics was taken into account in the calculation. Our results establish important benchmark conditions for improving the accuracy of chemical shift calculations in proteins and may aid in the validation of protein structure models derived by MAS NMR.
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Affiliation(s)
- Jodi Kraus
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, United States
- Pittsburgh Center for HIV Protein Interactions, University of Pittsburgh School of Medicine, 1051 Biomedical Science Tower 3, 3501 Fifth Ave., Pittsburgh, PA 15261, United States
| | - Rupal Gupta
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, United States
- Department of Chemistry, The College of Staten Island, 2800 Victory Blvd, Staten Island, NY 10314
| | - Manman Lu
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, United States
- Pittsburgh Center for HIV Protein Interactions, University of Pittsburgh School of Medicine, 1051 Biomedical Science Tower 3, 3501 Fifth Ave., Pittsburgh, PA 15261, United States
- Department of Structural Biology, University of Pittsburgh School of Medicine, 3501 Fifth Ave., Pittsburgh, PA 15261, United States
| | - Angela M. Gronenborn
- Pittsburgh Center for HIV Protein Interactions, University of Pittsburgh School of Medicine, 1051 Biomedical Science Tower 3, 3501 Fifth Ave., Pittsburgh, PA 15261, United States
- Department of Structural Biology, University of Pittsburgh School of Medicine, 3501 Fifth Ave., Pittsburgh, PA 15261, United States
| | - Mikael Akke
- Division of Biophysical Chemistry, Center for Molecular Protein Science, Department of Chemistry, Lund University, P.O. Box 124, SE-22100 Lund, Sweden
| | - Tatyana Polenova
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, United States
- Pittsburgh Center for HIV Protein Interactions, University of Pittsburgh School of Medicine, 1051 Biomedical Science Tower 3, 3501 Fifth Ave., Pittsburgh, PA 15261, United States
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87
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Solid-state NMR spectroscopy for characterization of RNA and RNP complexes. Biochem Soc Trans 2020; 48:1077-1087. [PMID: 32573690 DOI: 10.1042/bst20191080] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 05/24/2020] [Accepted: 05/27/2020] [Indexed: 12/15/2022]
Abstract
Ribonucleic acids are driving a multitude of biological processes where they act alone or in complex with proteins (ribonucleoproteins, RNP). To understand these processes both structural and mechanistic information about RNA is necessary. Due to their conformational plasticity RNA pose a challenge for mainstream structural biology methods. Solid-state NMR (ssNMR) spectroscopy is an emerging technique that can be applied to biomolecular complexes of any size in close-to-native conditions. This review outlines recent methodological developments in ssNMR for structural characterization of RNA and protein-RNA complexes and provides relevant examples.
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88
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Boatz JC, Piretra T, Lasorsa A, Matlahov I, Conway JF, van der Wel PCA. Protofilament Structure and Supramolecular Polymorphism of Aggregated Mutant Huntingtin Exon 1. J Mol Biol 2020; 432:4722-4744. [PMID: 32598938 DOI: 10.1016/j.jmb.2020.06.021] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2020] [Revised: 06/01/2020] [Accepted: 06/18/2020] [Indexed: 12/11/2022]
Abstract
Huntington's disease is a progressive neurodegenerative disease caused by expansion of the polyglutamine domain in the first exon of huntingtin (HttEx1). The extent of expansion correlates with disease progression and formation of amyloid-like protein deposits within the brain. The latter display polymorphism at the microscopic level, both in cerebral tissue and in vitro. Such polymorphism can dramatically influence cytotoxicity, leading to much interest in the conditions and mechanisms that dictate the formation of polymorphs. We examine conditions that govern HttEx1 polymorphism in vitro, including concentration and the role of the non-polyglutamine flanking domains. Using electron microscopy, we observe polymorphs that differ in width and tendency for higher-order bundling. Strikingly, aggregation yields different polymorphs at low and high concentrations. Narrow filaments dominate at low concentrations that may be more relevant in vivo. We dissect the role of N- and C-terminal flanking domains using protein with the former (httNT or N17) largely removed. The truncated protein is generated by trypsin cleavage of soluble HttEx1 fusion protein, which we analyze in some detail. Dye binding and solid-state NMR studies reveal changes in fibril surface characteristics and flanking domain mobility. Higher-order interactions appear facilitated by the C-terminal tail, while the polyglutamine forms an amyloid core resembling those of other polyglutamine deposits. Fibril-surface-mediated branching, previously attributed to secondary nucleation, is reduced in absence of httNT. A new model for the architecture of the HttEx1 filaments is presented and discussed in context of the assembly mechanism and biological activity.
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Affiliation(s)
- Jennifer C Boatz
- Department of Structural Biology, School of Medicine, University of Pittsburgh, 3501 5th Ave, Biomedical Science Tower 3, Pittsburgh, PA 15213, USA.
| | - Talia Piretra
- Department of Structural Biology, School of Medicine, University of Pittsburgh, 3501 5th Ave, Biomedical Science Tower 3, Pittsburgh, PA 15213, USA.
| | - Alessia Lasorsa
- Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747, AG, Groningen, the Netherlands.
| | - Irina Matlahov
- Department of Structural Biology, School of Medicine, University of Pittsburgh, 3501 5th Ave, Biomedical Science Tower 3, Pittsburgh, PA 15213, USA; Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747, AG, Groningen, the Netherlands.
| | - James F Conway
- Department of Structural Biology, School of Medicine, University of Pittsburgh, 3501 5th Ave, Biomedical Science Tower 3, Pittsburgh, PA 15213, USA.
| | - Patrick C A van der Wel
- Department of Structural Biology, School of Medicine, University of Pittsburgh, 3501 5th Ave, Biomedical Science Tower 3, Pittsburgh, PA 15213, USA; Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747, AG, Groningen, the Netherlands.
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89
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Dregni AJ, Duan P, Hong M. Hydration and Dynamics of Full-Length Tau Amyloid Fibrils Investigated by Solid-State Nuclear Magnetic Resonance. Biochemistry 2020; 59:2237-2248. [PMID: 32453948 PMCID: PMC7720860 DOI: 10.1021/acs.biochem.0c00342] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The microtubule-associated protein tau aggregates into distinct neurofibrillary tangles in brains afflicted with multiple neurodegenerative diseases such as Alzheimer's disease and corticobasal degeneration (CBD). The mechanism of tau misfolding and aggregation is poorly understood. Determining the structure, dynamics, and water accessibility of tau filaments may provide insight into the pathway of tau misfolding. Here, we investigate the hydration and dynamics of the β-sheet core of heparin-fibrillized 0N4R tau using solid-state nuclear magnetic resonance spectroscopy. This β-sheet core consists of the second and third microtubule-binding repeats, R2 and R3, respectively, which form a hairpin. Water-edited two-dimensional (2D) 13C-13C and 15N-13C correlation spectra show that most residues in R2 and R3 domains have low water accessibility, indicating that this hairpin is surrounded by other proteinaceous segments. However, a small number of residues, especially S285 and S316, are well hydrated compared to other Ser and Thr residues, suggesting that there is a small water channel in the middle of the hairpin. To probe whether water accessibility correlates with protein dynamics, we measured the backbone N-H dipolar couplings of the β-sheet core. Interestingly, residues in the fourth microtubule-binding repeat, R4, show rigid-limit N-H dipolar couplings, even though this domain exhibits weaker intensities in the 2D 15N-13C correlation spectra. These results suggest that the R4 domain participates in cross-β hydrogen bonding in some of the subunits but exhibits dynamic disorder in other subunits. Taken together, these hydration and dynamics data indicate that the R2-R3 hairpin of 0N4R tau is shielded from water by other proteinaceous segments on the exterior but contains a small water pore in the interior. This structural topology has various similarities with the CBD tau fibril structure but also shows specific differences. The disorder of the R4 domain and the presence of a small water channel in the heparin-fibrillized 4R tau have implications for the structure of tau fibrils in diseased brains.
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Affiliation(s)
| | | | - Mei Hong
- Department of Chemistry, Massachusetts Institute of Technology, 170 Albany Street, Cambridge, MA 02139
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90
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Niu Z, Sarkar R, Aichler M, Wester HJ, Yousefi BH, Reif B. Mapping the Binding Interface of PET Tracer Molecules and Alzheimer Disease Aβ Fibrils by Using MAS Solid-State NMR Spectroscopy. Chembiochem 2020; 21:2495-2502. [PMID: 32291951 PMCID: PMC7496087 DOI: 10.1002/cbic.202000143] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 04/10/2020] [Indexed: 12/13/2022]
Abstract
Positron emission tomography (PET) tracer molecules like thioflavin T specifically recognize amyloid deposition in brain tissue by selective binding to hydrophobic or aromatic surface grooves on the β‐sheet surface along the fibril axis. The molecular basis of this interaction is, however, not well understood. We have employed magic angle spinning (MAS) solid‐state NMR spectroscopy to characterize Aβ‐PET tracer complexes at atomic resolution. We established a titration protocol by using bovine serum albumin as a carrier to transfer hydrophobic small molecules to Aβ(1‐40) fibrillar aggregates. The same Aβ(1‐40) amyloid fibril sample was employed in subsequent titrations to minimize systematic errors that potentially arise from sample preparation. In the experiments, the small molecules 13C‐methylated Pittsburgh compound B (PiB) as well as a novel Aβ tracer based on a diarylbithiazole (DABTA) scaffold were employed. Classical 13C‐detected as well as proton‐detected spectra of protonated and perdeuterated samples with back‐substituted protons, respectively, were acquired and analyzed. After titration of the tracers, chemical‐shift perturbations were observed in the loop region involving residues Gly25‐Lys28 and Ile32‐Gly33, thus suggesting that the PET tracer molecules interact with the loop region connecting β‐sheets β1 and β2 in Aβ fibrils. We found that titration of the PiB derivatives suppressed fibril polymorphism and stabilized the amyloid fibril structure.
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Affiliation(s)
- Zheng Niu
- Munich Center for Integrated Protein Science (CIPS-M) Department Chemie, Technische Universität München, Lichtenbergstrasse 4, 85747, Garching, Germany.,Helmholtz-Zentrum München, Institute of Structural Biology (STB), Ingolstädter Landstrasse 1, 85764, Neuherberg, Germany
| | - Riddhiman Sarkar
- Munich Center for Integrated Protein Science (CIPS-M) Department Chemie, Technische Universität München, Lichtenbergstrasse 4, 85747, Garching, Germany.,Helmholtz-Zentrum München, Institute of Structural Biology (STB), Ingolstädter Landstrasse 1, 85764, Neuherberg, Germany
| | - Michaela Aichler
- Helmholtz Zentrum München, Research Unit Analytical Pathology (AAP), Ingolstädter Landstrasse 1, 85764, Neuherberg, Germany
| | - Hans-Jürgen Wester
- Technische Universität München, Department of Pharmaceutical Radiochemistry, Walther-Meißner-Strasse 3, 85748, Garching, Germany
| | - Behrooz Hooshyar Yousefi
- Technische Universität München, Department of Pharmaceutical Radiochemistry, Walther-Meißner-Strasse 3, 85748, Garching, Germany.,Philipps University of Marburg, Department of Nuclear Medicine, Baldingerstrasse. 1, 35043, Marburg, Germany
| | - Bernd Reif
- Munich Center for Integrated Protein Science (CIPS-M) Department Chemie, Technische Universität München, Lichtenbergstrasse 4, 85747, Garching, Germany.,Helmholtz-Zentrum München, Institute of Structural Biology (STB), Ingolstädter Landstrasse 1, 85764, Neuherberg, Germany
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91
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Gopinath T, Weber DK, Veglia G. Multi-receiver solid-state NMR using polarization optimized experiments (POE) at ultrafast magic angle spinning. JOURNAL OF BIOMOLECULAR NMR 2020; 74:267-285. [PMID: 32333193 PMCID: PMC7236978 DOI: 10.1007/s10858-020-00316-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2019] [Accepted: 04/11/2020] [Indexed: 05/04/2023]
Abstract
Ultrafast magic angle spinning (MAS) technology and 1H detection have dramatically enhanced the sensitivity of solid-state NMR (ssNMR) spectroscopy of biopolymers. We previously showed that, when combined with polarization optimized experiments (POE), these advancements enable the simultaneous acquisition of multi-dimensional 1H- or 13C-detected experiments using a single receiver. Here, we propose a new sub-class within the POE family, namely HC-DUMAS, HC-MEIOSIS, and HC-MAeSTOSO, that utilize dual receiver technology for the simultaneous detection of 1H and 13C nuclei. We also expand this approach to record 1H-, 13C-, and 15N-detected homonuclear 2D spectra simultaneously using three independent receivers. The combination of POE and multi-receiver technology will further shorten the total experimental time of ssNMR experiments for biological solids.
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Affiliation(s)
- T Gopinath
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, 6-155 Jackson Hall, Minneapolis, MN, 55455, USA
| | - Daniel K Weber
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, 6-155 Jackson Hall, Minneapolis, MN, 55455, USA
| | - Gianluigi Veglia
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, 6-155 Jackson Hall, Minneapolis, MN, 55455, USA.
- Department of Chemistry, University of Minnesota, Minneapolis, MN, 55455, USA.
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92
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Hoffmann J, Ruta J, Shi C, Hendriks K, Chevelkov V, Franks WT, Oschkinat H, Giller K, Becker S, Lange A. Protein resonance assignment by BSH-CP-based 3D solid-state NMR experiments: A practical guide. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2020; 58:445-465. [PMID: 31691361 DOI: 10.1002/mrc.4945] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Revised: 07/05/2019] [Accepted: 09/17/2019] [Indexed: 06/10/2023]
Abstract
Solid-state NMR (ssNMR) spectroscopy has evolved into a powerful method to obtain structural information and to study the dynamics of proteins at atomic resolution and under physiological conditions. The method is especially well suited to investigate insoluble and noncrystalline proteins that cannot be investigated easily by X-ray crystallography or solution NMR. To allow for detailed analysis of ssNMR data, the assignment of resonances to the protein atoms is essential. For this purpose, a set of three-dimensional (3D) spectra needs to be acquired. Band-selective homo-nuclear cross-polarization (BSH-CP) is an effective method for magnetization transfer between carbonyl carbon (CO) and alpha carbon (CA) atoms, which is an important transfer step in multidimensional ssNMR experiments. This tutorial describes the detailed procedure for the chemical shift assignment of the backbone atoms of 13 C-15 N-labeled proteins by BSH-CP-based 13 C-detected ssNMR experiments. A set of six 3D experiments is used for unambiguous assignment of the protein backbone as well as certain side-chain resonances. The tutorial especially addresses scientists with little experience in the field of ssNMR and provides all the necessary information for protein assignment in an efficient, time-saving approach.
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Affiliation(s)
- Jutta Hoffmann
- Department of Molecular Biophysics, Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Berlin, Germany
| | - Julia Ruta
- Department of Molecular Biophysics, Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Berlin, Germany
| | - Chaowei Shi
- Department of Molecular Biophysics, Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Berlin, Germany
| | - Kitty Hendriks
- Department of Molecular Biophysics, Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Berlin, Germany
| | - Veniamin Chevelkov
- Department of Molecular Biophysics, Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Berlin, Germany
| | - W Trent Franks
- Department of NMR-supported Structural Biology, Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Berlin, Germany
| | - Hartmut Oschkinat
- Department of NMR-supported Structural Biology, Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Berlin, Germany
| | - Karin Giller
- Department of NMR-based Structural Biology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Stefan Becker
- Department of NMR-based Structural Biology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Adam Lange
- Department of Molecular Biophysics, Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Berlin, Germany
- Institut für Biologie, Humboldt-Universität zu Berlin, Berlin, Germany
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93
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Dasari AKR, Hung I, Michael B, Gan Z, Kelly JW, Connors LH, Griffin RG, Lim KH. Structural Characterization of Cardiac Ex Vivo Transthyretin Amyloid: Insight into the Transthyretin Misfolding Pathway In Vivo. Biochemistry 2020; 59:1800-1803. [PMID: 32338497 DOI: 10.1021/acs.biochem.0c00091] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Structural characterization of misfolded protein aggregates is essential to understanding the molecular mechanism of protein aggregation associated with various protein misfolding disorders. Here, we report structural analyses of ex vivo transthyretin aggregates extracted from human cardiac tissue. Comparative structural analyses of in vitro and ex vivo transthyretin aggregates using various biophysical techniques revealed that cardiac transthyretin amyloid has structural features similar to those of in vitro transthyretin amyloid. Our solid-state nuclear magnetic resonance studies showed that in vitro amyloid contains extensive nativelike β-sheet structures, while other loop regions including helical structures are disrupted in the amyloid state. These results suggest that transthyretin undergoes a common misfolding and aggregation transition to nativelike aggregation-prone monomers that self-assemble into amyloid precipitates in vitro and in vivo.
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Affiliation(s)
- Anvesh K R Dasari
- Department of Chemistry, East Carolina University, Greenville, North Carolina 27858, United States
| | - Ivan Hung
- Center of Interdisciplinary Magnetic Resonance (CIMAR), National High Magnetic Field Laboratory (NHMFL), 1800 East Paul Dirac Drive, Tallahassee, Florida 32310, United States
| | - Brian Michael
- Department of Chemistry, Massachuseets Institute of Technology, NW14-3220, 170 Albany Street, Cambridge, Massachusetts 02139-4703, United States
| | - Zhehong Gan
- Center of Interdisciplinary Magnetic Resonance (CIMAR), National High Magnetic Field Laboratory (NHMFL), 1800 East Paul Dirac Drive, Tallahassee, Florida 32310, United States
| | - Jeffery W Kelly
- Department of Molecular and Experimental Medicine, Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, California 92037, United States
| | - Lawreen H Connors
- Department of Pathology and Laboratory Medicine, Boston University School of Medicine, 72 East Concord Street, Boston, Massachusetts 02118, United States
| | - Robert G Griffin
- Department of Chemistry, Massachuseets Institute of Technology, NW14-3220, 170 Albany Street, Cambridge, Massachusetts 02139-4703, United States
| | - Kwang Hun Lim
- Department of Chemistry, East Carolina University, Greenville, North Carolina 27858, United States
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94
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Zhang J, Wang J, Ma C, Lu J. Hydroxyapatite Formation Coexists with Amyloid-like Self-Assembly of Human Amelogenin. Int J Mol Sci 2020; 21:E2946. [PMID: 32331340 PMCID: PMC7216246 DOI: 10.3390/ijms21082946] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 03/28/2020] [Accepted: 04/07/2020] [Indexed: 12/19/2022] Open
Abstract
Tooth enamel is formed in an extracellular environment. Amelogenin, the major component in the protein matrix of tooth enamel during the developing stage, could assemble into high molecular weight structures, regulating enamel formation. However, the molecular structure of amelogenin protein assembly at the functional state is still elusive. In this work, we found that amelogenin is able to induce calcium phosphate minerals into hydroxyapatite (HAP) structure in vitro at pH 6.0. Assessed using X-ray diffraction (XRD) and 31P solid-state NMR (SSNMR) evidence, the formed HAP mimics natural enamel closely. The structure of amelogenin protein assembly coexisting with the HAP was also studied using atomic force microscopy (AFM), transmission electron microscopy (TEM) and XRD, indicating the β-amyloid structure of the protein. SSNMR was proven to be an important tool in detecting both the rigid and dynamic components of the protein assembly in the sample, and the core sequence 18EVLTPLKWYQSI29 was identified as the major segment contributing to the β-sheet secondary structure. Our research suggests an amyloid structure may be an important factor in controlling HAP formation at the right pH conditions with the help of other structural components in the protein assembly.
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Affiliation(s)
- Jing Zhang
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China; (J.Z.); (J.W.); (C.M.)
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai 200031, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jian Wang
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China; (J.Z.); (J.W.); (C.M.)
| | - Chengwei Ma
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China; (J.Z.); (J.W.); (C.M.)
| | - Junxia Lu
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China; (J.Z.); (J.W.); (C.M.)
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95
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Zhuo XF, Wang J, Zhang J, Jiang LL, Hu HY, Lu JX. Solid-State NMR Reveals the Structural Transformation of the TDP-43 Amyloidogenic Region upon Fibrillation. J Am Chem Soc 2020; 142:3412-3421. [PMID: 32003979 DOI: 10.1021/jacs.9b10736] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
TDP-43 is a primary pathological hallmark protein of amyotrophic lateral sclerosis and frontotemporal lobar degeneration, which may exist in the form of amyloid inclusions in the cells of patients. In addition to serving as a biomarker for these diseases, TDP-43 can also directly trigger neurodegeneration. We previously determined the amyloidogenic core region of TDP-43 (residues 311-360) and showed by solution NMR that this region includes two α-helices [(321-330) and (335-343)] in solution. We suggested that the helix-to-sheet structural transformation initiates TDP-43 aggregation. In the present study, X-ray diffraction shows that TDP-43 (311-360) aggregates adopt a cross-β structure. Thioredoxin (Trx)-fused TDP-43 (311-360) can undergo liquid-liquid phase separation (LLPS) before fibrillation, suggesting that phase separation is an intermediate step before amyloid formation. Solid-state NMR (SSNMR), carried out to elucidate the structural changes of TDP-43 (311-360) at the atomic level, indicates five β-strands of the amyloids formed, with the major two β-strands contributed by the first helical region in the solution structure. The NMR evidence is also in support of the fibril having a parallel in-register conformation, implying a mechanism in which the helix-helix interactions in LLPS are converted into β-strand parallel lateral association upon fibrillation. Our studies have assigned many key interresidue interactions that contribute to the stability of the fibril, including F316 with I318 and Q327 and W334 with A325, A326, A329, and S332. SSNMR with 1H detection reveals a unique close interaction between the indole Nε1-Hε1 of W334 and the side-chain carbonyl of Q343. This interaction could be a very important factor in initiating TDP-43 (311-360) folding/misfolding in LLPS.
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Affiliation(s)
- Xiao-Feng Zhuo
- School of Life Science and Technology , ShanghaiTech University , Shanghai 201210 , People's Republic of China.,State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science , Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences , Shanghai 200031 , People's Republic of China.,University of Chinese Academy of Sciences , Beijing 100049 , People's Republic of China
| | - Jian Wang
- School of Life Science and Technology , ShanghaiTech University , Shanghai 201210 , People's Republic of China
| | - Jing Zhang
- School of Life Science and Technology , ShanghaiTech University , Shanghai 201210 , People's Republic of China.,State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science , Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences , Shanghai 200031 , People's Republic of China.,University of Chinese Academy of Sciences , Beijing 100049 , People's Republic of China
| | - Lei-Lei Jiang
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science , Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences , Shanghai 200031 , People's Republic of China
| | - Hong-Yu Hu
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science , Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences , Shanghai 200031 , People's Republic of China
| | - Jun-Xia Lu
- School of Life Science and Technology , ShanghaiTech University , Shanghai 201210 , People's Republic of China
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96
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Conformational changes upon gating of KirBac1.1 into an open-activated state revealed by solid-state NMR and functional assays. Proc Natl Acad Sci U S A 2020; 117:2938-2947. [PMID: 31980523 PMCID: PMC7022178 DOI: 10.1073/pnas.1915010117] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Inward rectifier K+ (Kir) channels play an important role in reestablishing the resting membrane state of the action potential of excitable cells in humans. KirBac1.1 is a prokaryotic Kir channel with a high degree of homology to human Kir channels and can be isotopically labeled in NMR quantities for structural studies. Functional assays and NMR assignments confirm that KirBac1.1 is in a constitutively conductive state. Solid-state NMR assignments further reveal alternate conformations at key sites in the protein that are well conserved through human Kir channels, hinting at a possible allosteric network between channels. These underlying sequential and structural motifs could explain abnormal conductive properties of these channels fundamental to their native gating processes. The conformational changes required for activation and K+ conduction in inward-rectifier K+ (Kir) channels are still debated. These structural changes are brought about by lipid binding. It is unclear how this process relates to fast gating or if the intracellular and extracellular regions of the protein are coupled. Here, we examine the structural details of KirBac1.1 reconstituted into both POPC and an activating lipid mixture of 3:2 POPC:POPG (wt/wt). KirBac1.1 is a prokaryotic Kir channel that shares homology with human Kir channels. We establish that KirBac1.1 is in a constitutively active state in POPC:POPG bilayers through the use of real-time fluorescence quenching assays and Förster resonance energy transfer (FRET) distance measurements. Multidimensional solid-state NMR (SSNMR) spectroscopy experiments reveal two different conformers within the transmembrane regions of the protein in this activating lipid environment, which are distinct from the conformation of the channel in POPC bilayers. The differences between these three distinct channel states highlight conformational changes associated with an open activation gate and suggest a unique allosteric pathway that ties the selectivity filter to the activation gate through interactions between both transmembrane helices, the turret, selectivity filter loop, and the pore helix. We also identify specific residues involved in this conformational exchange that are highly conserved among human Kir channels.
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97
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Murray DT, Tycko R. Side Chain Hydrogen-Bonding Interactions within Amyloid-like Fibrils Formed by the Low-Complexity Domain of FUS: Evidence from Solid State Nuclear Magnetic Resonance Spectroscopy. Biochemistry 2020; 59:364-378. [PMID: 31895552 DOI: 10.1021/acs.biochem.9b00892] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In aqueous solutions, the 214-residue low-complexity domain of the FUS protein (FUS-LC) is known to undergo liquid-liquid phase separation and also to self-assemble into amyloid-like fibrils. In previous work based on solid state nuclear magnetic resonance (ssNMR) methods, a structural model for the FUS-LC fibril core was developed, showing that residues 39-95 form the fibril core. Unlike fibrils formed by amyloid-β peptides, α-synuclein, and other amyloid-forming proteins, the FUS-LC core is largely devoid of purely hydrophobic amino acid side chains. Instead, the core-forming segment contains numerous hydroxyl-bearing residues, including 18 serines, six threonines, and eight tyrosines, suggesting that the FUS-LC fibril structure may be stabilized in part by inter-residue hydrogen bonds among side chain hydroxyl groups. Here we describe ssNMR measurements, performed on 2H,15N,13C-labeled FUS-LC fibrils, that provide new information about the interactions of hydroxyl-bearing residues with one another and with water. The ssNMR data support the involvement of specific serine, threonine, and tyrosine residues in hydrogen-bonding interactions. The data also reveal differences in hydrogen exchange rates with water for different side chain hydroxyl groups, providing information about solvent exposure and penetration of water into the FUS-LC fibril core.
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Affiliation(s)
- Dylan T Murray
- Department of Chemistry , University of California , Davis , California 95616-5271 , United States
| | - Robert Tycko
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases , National Institutes of Health , Bethesda , Maryland 20892-0520 , United States
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98
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Gopinath T, Veglia G. Proton-detected polarization optimized experiments (POE) using ultrafast magic angle spinning solid-state NMR: Multi-acquisition of membrane protein spectra. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2020; 310:106664. [PMID: 31837552 PMCID: PMC7003683 DOI: 10.1016/j.jmr.2019.106664] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 11/26/2019] [Accepted: 11/27/2019] [Indexed: 05/05/2023]
Abstract
Proton-detected solid-state NMR (ssNMR) spectroscopy has dramatically improved the sensitivity and resolution of fast magic angle spinning (MAS) methods. While relatively straightforward for fibers and crystalline samples, the routine application of these techniques to membrane protein samples is still challenging. This is due to the low sensitivity of these samples, which require high lipid:protein ratios to maintain the structural and functional integrity of membrane proteins. We previously introduced a family of novel polarization optimized experiments (POE) that enable to make the best of nuclear polarization and obtain multiple-acquisitions from a single pulse sequence and one receiver. Here, we present the 1H-detected versions of POE using ultrafast MAS ssNMR. Specifically, we implemented proton detection into our three main POE strategies, H-DUMAS, H-MEIOSIS, and H-MAeSTOSO, achieving the acquisition of up to ten different experiments using a single pulse sequence. We tested these experiments on a model compound N-Acetyl-Val-Leu dipeptide and applied to a six transmembrane acetate transporter, SatP, reconstituted in lipid membranes. These new methods will speed up the spectroscopy of challenging biomacromolecules such as membrane proteins.
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Affiliation(s)
- T Gopinath
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, United States
| | - Gianluigi Veglia
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, United States; Department of Chemistry, University of Minnesota, Minneapolis, MN 55455, United States.
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99
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Gibbs E, Perrone B, Hassan A, Kümmerle R, Kriwacki R. NPM1 exhibits structural and dynamic heterogeneity upon phase separation with the p14ARF tumor suppressor. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2020; 310:106646. [PMID: 31751897 PMCID: PMC6934896 DOI: 10.1016/j.jmr.2019.106646] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Revised: 11/04/2019] [Accepted: 11/08/2019] [Indexed: 06/10/2023]
Abstract
Nucleophosmin (NPM1) is an abundant nucleolar protein that aids in the maturation of pre-ribosomal particles and participates in oncogenic stress responses through its interaction with the Alternative Reading Frame tumor suppressor (p14ARF). NPM1 mediates multiple mechanisms of phase separation which contribute to the liquid-like properties of nucleoli. However, the effects of phase separation on the structure and dynamics of NPM1 are poorly understood. Here we show that NPM1 undergoes phase separation with p14ARF in vitro, forming condensates that immobilize both proteins. We probed the structure and dynamics of NPM1 within the condensed phase using solid-state NMR spectroscopy. Our results demonstrate that within the condensed phase, the NPM1 oligomerization domain forms an immobile scaffold, while the central intrinsically disordered region and the C-terminal nucleic acid binding domain exhibit relative mobility.
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Affiliation(s)
- Eric Gibbs
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, United States
| | - Barbara Perrone
- Bruker Switzerland AG, Industriestrasse 26, CH-8117 Fällanden, Switzerland
| | - Alia Hassan
- Bruker Switzerland AG, Industriestrasse 26, CH-8117 Fällanden, Switzerland
| | - Rainer Kümmerle
- Bruker Switzerland AG, Industriestrasse 26, CH-8117 Fällanden, Switzerland
| | - Richard Kriwacki
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, United States; Department of Microbiology, Immunology and Biochemistry, University of Tennessee Health Sciences Center, Memphis, United States.
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100
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Atherton J, Luo Y, Xiang S, Yang C, Rai A, Jiang K, Stangier M, Vemu A, Cook AD, Wang S, Roll-Mecak A, Steinmetz MO, Akhmanova A, Baldus M, Moores CA. Structural determinants of microtubule minus end preference in CAMSAP CKK domains. Nat Commun 2019; 10:5236. [PMID: 31748546 PMCID: PMC6868217 DOI: 10.1038/s41467-019-13247-6] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Accepted: 10/23/2019] [Indexed: 12/20/2022] Open
Abstract
CAMSAP/Patronins regulate microtubule minus-end dynamics. Their end specificity is mediated by their CKK domains, which we proposed recognise specific tubulin conformations found at minus ends. To critically test this idea, we compared the human CAMSAP1 CKK domain (HsCKK) with a CKK domain from Naegleria gruberi (NgCKK), which lacks minus-end specificity. Here we report near-atomic cryo-electron microscopy structures of HsCKK- and NgCKK-microtubule complexes, which show that these CKK domains share the same protein fold, bind at the intradimer interprotofilament tubulin junction, but exhibit different footprints on microtubules. NMR experiments show that both HsCKK and NgCKK are remarkably rigid. However, whereas NgCKK binding does not alter the microtubule architecture, HsCKK remodels its microtubule interaction site and changes the underlying polymer structure because the tubulin lattice conformation is not optimal for its binding. Thus, in contrast to many MAPs, the HsCKK domain can differentiate subtly specific tubulin conformations to enable microtubule minus-end recognition.
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Affiliation(s)
- Joseph Atherton
- Institute of Structural and Molecular Biology, Birkbeck, University of London, Malet Street, London, UK.
| | - Yanzhang Luo
- NMR Spectroscopy, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands
| | - Shengqi Xiang
- NMR Spectroscopy, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands
- MOE Key Lab for biomolecular Condensates & Cellular Dynamics, School of Life Sciences, University of Science and Technology of China, 96 Jinzhai Road, Hefei, 230026, Anhui, China
| | - Chao Yang
- Cell Biology, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands
| | - Ankit Rai
- Cell Biology, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands
| | - Kai Jiang
- Medical Research Institute, School of Medicine, Wuhan University, 430071, Wuhan, China
| | - Marcel Stangier
- Laboratory of Biomolecular Research, Division of Biology and Chemistry, Paul Scherrer Institut, Villigen, PSI, Switzerland
| | - Annapurna Vemu
- Cell Biology and Biophysics Unit, National Institute of Neurological Disorders and Stroke, Bethesda, MD, 20892, USA
| | - Alexander D Cook
- Institute of Structural and Molecular Biology, Birkbeck, University of London, Malet Street, London, UK
| | - Su Wang
- Institute of Structural and Molecular Biology, Birkbeck, University of London, Malet Street, London, UK
| | - Antonina Roll-Mecak
- Cell Biology and Biophysics Unit, National Institute of Neurological Disorders and Stroke, Bethesda, MD, 20892, USA
- Biophysics Center, National Heart, Lung and Blood Institute, Bethesda, MD, 20892, USA
| | - Michel O Steinmetz
- Laboratory of Biomolecular Research, Division of Biology and Chemistry, Paul Scherrer Institut, Villigen, PSI, Switzerland
- University of Basel, Biozentrum, CH-4056, Basel, Switzerland
| | - Anna Akhmanova
- Cell Biology, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands
| | - Marc Baldus
- NMR Spectroscopy, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands.
| | - Carolyn A Moores
- Institute of Structural and Molecular Biology, Birkbeck, University of London, Malet Street, London, UK.
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