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Pardo-Avila F, Kudva R, Levitt M, von Heijne G. Single-residue effects on the behavior of a nascent polypeptide chain inside the ribosome exit tunnel. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.08.20.608737. [PMID: 39229094 PMCID: PMC11370347 DOI: 10.1101/2024.08.20.608737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 09/05/2024]
Abstract
Nascent polypeptide chains (NCs) are extruded from the ribosome through an exit tunnel (ET) traversing the large ribosomal subunit. The ET's irregular and chemically complex wall allows for various NC-ET interactions. Translational arrest peptides (APs) bind in the ET to induce translational arrest, a property that can be exploited to study NC-ET interactions by Force Profile Analysis (FPA). We employed FPA and molecular dynamics (MD) simulations to investigate how individual residues placed in a glycine-serine repeat segment within an AP-stalled NC interact with the ET to exert a pulling force on the AP and release stalling. Our results indicate that large and hydrophobic residues generate a pulling force on the NC when placed ≳10 residues away from the peptidyl transfer center (PTC). Moreover, an asparagine placed 12 residues from the PTC makes a specific stabilizing interaction with the tip of ribosomal protein uL22 that reduces the pulling force on the NC, while a lysine or leucine residue in the same position increases the pulling force. Finally, the MD simulations suggest how the Mannheimia succiniproducens SecM AP interacts with the ET to promote translational stalling.
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Affiliation(s)
- Fátima Pardo-Avila
- Department of Structural Biology, Stanford University, Palo Alto, CA, USA
| | - Renuka Kudva
- Department of Biochemistry and Biophysics, Stockholm University, SE-106 91 Stockholm, Sweden
- Science for Life Laboratory Stockholm University, Box 1031, SE-171 21 Solna, Sweden
| | - Michael Levitt
- Department of Structural Biology, Stanford University, Palo Alto, CA, USA
| | - Gunnar von Heijne
- Department of Biochemistry and Biophysics, Stockholm University, SE-106 91 Stockholm, Sweden
- Science for Life Laboratory Stockholm University, Box 1031, SE-171 21 Solna, Sweden
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2
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Templeton C, Hamilton I, Russell R, Elber R. Impact of Ion-Mixing Entropy on Orientational Preferences of DNA Helices: FRET Measurements and Computer Simulations. J Phys Chem B 2023; 127:8796-8808. [PMID: 37815452 PMCID: PMC11341850 DOI: 10.1021/acs.jpcb.3c04354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/11/2023]
Abstract
Biological processes require DNA and RNA helices to pack together in specific interhelical orientations. While electrostatic repulsion between backbone charges is expected to be maximized when helices are in parallel alignment, such orientations are commonplace in nature. To better understand how the repulsion is overcome, we used experimental and computational approaches to investigate how the orientational preferences of DNA helices depend on the concentration and valence of mobile cations. We used Förster resonance energy transfer (FRET) to probe the relative orientations of two 24-bp helices held together via a freely rotating PEG linker. At low cation concentrations, the helices preferred more "cross"-like orientations over those closer to parallel, and this preference was reduced with increasing salt concentrations. The results were in good quantitative agreement with Poisson-Boltzmann (PB) calculations for monovalent salt (Na+). However, PB underestimated the ability of mixtures of monovalent and divalent ions (Mg2+) to reduce the conformational preference. As a complementary approach, we performed all-atom molecular dynamics (MD) simulations and found better agreement with the experimental results. While MD and PB predict similar electrostatic forces, MD predicts a greater accumulation of Mg2+ in the ion atmosphere surrounding the DNA. Mg2+ occupancy is predicted to be greater in conformations close to the parallel orientation than in conformations close to the crossed orientation, enabling a greater release of Na+ ions and providing an entropic gain (one bound ion for two released). MD predicts an entropy gain larger than that of PB because of the increased Mg2+ occupancy. The entropy changes have a negligible effect at low Mg2+ concentrations because the free energies are dominated by electrostatic repulsion. However, as the Mg2+ concentration increases, charge screening is more effective and the mixing entropy produces readily detectable changes in packing preferences. Our results underline the importance of mixing entropy of counterions in nucleic acid interactions and provide a new understanding on the impact of a mixed ion atmosphere on the packing of DNA helices.
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Affiliation(s)
- Clark Templeton
- Department of Chemical Engineering, University of Texas at Austin, Austin, TX 78712, USA
- Department of Physics, FU Berlin, 14195 Berlin, Germany
| | - Ian Hamilton
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA
| | - Rick Russell
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA
| | - Ron Elber
- Institute for Computational Engineering and Science, Department of Chemistry, University of Texas at Austin, Austin, TX 78712, USA
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3
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Joiret M, Kerff F, Rapino F, Close P, Geris L. A simple geometrical model of the electrostatic environment around the catalytic center of the ribosome and its significance for the elongation cycle kinetics. Comput Struct Biotechnol J 2023; 21:3768-3795. [PMID: 37560126 PMCID: PMC10407619 DOI: 10.1016/j.csbj.2023.07.016] [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: 04/27/2023] [Revised: 07/17/2023] [Accepted: 07/19/2023] [Indexed: 08/11/2023] Open
Abstract
The central function of the large subunit of the ribosome is to catalyze peptide bond formation. This biochemical reaction is conducted at the peptidyl transferase center (PTC). Experimental evidence shows that the catalytic activity is affected by the electrostatic environment around the peptidyl transferase center. Here, we set up a minimal geometrical model fitting the available x-ray solved structures of the ribonucleic cavity around the catalytic center of the large subunit of the ribosome. The purpose of this phenomenological model is to estimate quantitatively the electrostatic potential and electric field that are experienced during the peptidyl transfer reaction. At least two reasons motivate the need for developing this quantification. First, we inquire whether the electric field in this particular catalytic environment, made only of nucleic acids, is of the same order of magnitude as the one prevailing in catalytic centers of the proteic enzymes counterparts. Second, the protein synthesis rate is dependent on the nature of the amino acid sequentially incorporated in the nascent chain. The activation energy of the catalytic reaction and its detailed kinetics are shown to be dependent on the mechanical work exerted on the amino acids by the electric field, especially when one of the four charged amino acid residues (R, K, E, D) has previously been incorporated at the carboxy-terminal end of the peptidyl-tRNA. Physical values of the electric field provide quantitative knowledge of mechanical work, activation energy and rate of the peptide bond formation catalyzed by the ribosome. We show that our theoretical calculations are consistent with two independent sets of previously published experimental results. Experimental results for E.coli in the minimal case of the dipeptide bond formation when puromycin is used as the final amino acid acceptor strongly support our theoretically derived reaction time courses. Experimental Ribo-Seq results on E. coli and S. cerevisiae comparing the residence time distribution of ribosomes upon specific codons are also well accounted for by our theoretical calculations. The statistical queueing time theory was used to model the ribosome residence time per codon during nascent protein elongation and applied for the interpretation of the Ribo-Seq data. The hypo-exponential distribution fits the residence time observed distribution of the ribosome on a codon. An educated deconvolution of this distribution is used to estimate the rates of each elongation step in a codon specific manner. Our interpretation of all these results sheds light on the functional role of the electrostatic profile around the PTC and its impact on the ribosome elongation cycle.
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Affiliation(s)
- Marc Joiret
- Biomechanics Research Unit, GIGA in silico medicine, Liège University, CHU-B34(+5) 1 Avenue de l'Hôpital, 4000 Liège, Belgium
| | - Frederic Kerff
- UR InBios Centre d'Ingénierie des Protéines, Liège University, Bât B6a, Allèe du 6 Août, 19, B-4000 Liège, Belgium
| | - Francesca Rapino
- Cancer Signaling, GIGA Stem Cells, Liège University, CHU-B34(+2) 1 Avenue de l'Hôpital, B-4000 Liège, Belgium
| | - Pierre Close
- Cancer Signaling, GIGA Stem Cells, Liège University, CHU-B34(+2) 1 Avenue de l'Hôpital, B-4000 Liège, Belgium
| | - Liesbet Geris
- Biomechanics Research Unit, GIGA in silico medicine, Liège University, CHU-B34(+5) 1 Avenue de l'Hôpital, 4000 Liège, Belgium
- Skeletal Biology & Engineering Research Center, KU Leuven, ON I Herestraat 49 - box 813, 3000 Leuven, Belgium
- Biomechanics Section, KU Leuven, Celestijnenlaan 300C box 2419, B-3001 Heverlee, Belgium
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4
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Jia J, Xue X, Guan Y, Fan X, Wang Z. Biofilm characteristics and transcriptomic profiling of Acinetobacter johnsonii defines signatures for planktonic and biofilm cells. ENVIRONMENTAL RESEARCH 2022; 213:113714. [PMID: 35718162 DOI: 10.1016/j.envres.2022.113714] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 06/11/2022] [Accepted: 06/14/2022] [Indexed: 06/15/2023]
Abstract
Most bacteria in the natural environment have a biofilm mode of life, which is intrinsically tolerant to antibiotics. While until now, the knowledge of biofilm formation by Acinetobacter johnsonii is not well understood. In this study, the characteristics and the effect of a sub-inhibitory concentration of antibiotic on A. johnsonii biofilm and planktonic cells were determined. We discovered a positive relationship between biofilm formation and tetracycline resistance, and biofilms rapidly evolve resistance to tetracycline they are treated with. Persister cells commonly exist in both planktonic and biofilm cells, with a higher frequency in the latter. Further transcriptomic analysis speculates that the overexpression of multidrug resistance genes and stress genes were mainly answered to sub lethal concentration of tetracycline in planktonic cells, and the lower metabolic levels after biofilm formation result in high resistance level of biofilm cells to tetracycline. Altogether, these data suggest that A. johnsonii can adjust its phenotype when grown as biofilm and change its metabolism under antibiotic stress, and provide implications for subsequent biofilm control.
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Affiliation(s)
- Jia Jia
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Xue Xue
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Yongjing Guan
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Xiaoteng Fan
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Zaizhao Wang
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, 712100, China.
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5
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Thermodynamics of co-translational folding and ribosome-nascent chain interactions. Curr Opin Struct Biol 2022; 74:102357. [PMID: 35390638 DOI: 10.1016/j.sbi.2022.102357] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 02/22/2022] [Accepted: 02/22/2022] [Indexed: 11/03/2022]
Abstract
Proteins can begin the conformational search for their native structure in parallel with biosynthesis on the ribosome, in a process termed co-translational folding. In contrast to the reversible folding of isolated domains, as a nascent chain emerges from the ribosome exit tunnel during translation the free energy landscape it explores also evolves as a function of chain length. While this presents a substantially more complex measurement problem, this review will outline the progress that has been made recently in understanding, quantitatively, the process by which a nascent chain attains its full native stability, as well as the mechanisms through which interactions with the nearby ribosome surface can perturb or modulate this process.
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6
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Brakel A, Krizsan A, Itzenga R, Kraus CN, Otvos L, Hoffmann R. Influence of Substitutions in the Binding Motif of Proline-Rich Antimicrobial Peptide ARV-1502 on 70S Ribosome Binding and Antimicrobial Activity. Int J Mol Sci 2022; 23:ijms23063150. [PMID: 35328571 PMCID: PMC8950706 DOI: 10.3390/ijms23063150] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Revised: 03/07/2022] [Accepted: 03/11/2022] [Indexed: 01/10/2023] Open
Abstract
Proline-rich antimicrobial peptides (PrAMPs) are promising candidates to treat bacterial infections. The designer peptide ARV-1502 exhibits strong antimicrobial effects against Enterobacteriaceae both in vitro and in vivo. Since the inhibitory effects of ARV-1502 reported for the 70 kDa heat-shock protein DnaK do not fully explain the antimicrobial activity of its 176 substituted analogs, we further studied their effect on the bacterial 70S ribosome of Escherichia coli, a known target of PrAMPs. ARV-1502 analogues, substituted in positions 3, 4, and 8 to 12 (underlined) of the binding motif D3KPRPYLPRP12 with aspartic acid, lysine, serine, phenylalanine or leucine, were tested in a competitive fluorescence polarization (FP) binding screening assay using 5(6)-carboxyfluorescein-labeled (Cf-) ARV-1502 and the 70S ribosome isolated from E. coli BW25113. While their effect on ribosomal protein expression was studied for green fluorescent protein (GFP) in a cell-free expression system (in vitro translation), the importance of known PrAMP transporters SbmA and MdtM was investigated using E. coli BW25113 and the corresponding knockout mutants. The dissociation constant (Kd) of 201 ± 16 nmol/L obtained for Cf-ARV-1502 suggests strong binding to the E. coli 70S ribosome. An inhibitory binding assay indicated that the binding site overlaps with those of other PrAMPs including Onc112 and pyrrhocoricin as well as the non-peptidic antibiotics erythromycin and chloramphenicol. All these drugs and drug candidates bind to the exit-tunnel of the 70S ribosome. Substitutions of the C-terminal fragment of the binding motif YLPRP reduced binding. At the same time, inhibition of GFP expression increased with net peptide charge. Interestingly, the MIC values of wild-type and ΔsbmA and ΔmdtM knockout mutants indicated that substitutions in the ribosomal binding motif altered also the bacterial uptake, which was generally improved by incorporation of hydrophobic residues. In conclusion, most substituted ARV-1502 analogs bound weaker to the 70S ribosome than ARV-1502 underlining the importance of the YLPRP binding motif. The weaker ribosomal binding correlated well with decreased antimicrobial activity in vitro. Substituted ARV-1502 analogs with a higher level of hydrophobicity or positive net charge improved the ribosome binding, inhibition of translation, and bacterial uptake.
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Affiliation(s)
- Alexandra Brakel
- Faculty of Chemistry and Mineralogy, Institute of Bioanalytical Chemistry, Universität Leipzig, 04109 Leipzig, Germany; (A.K.); (R.I.)
- Center for Biotechnology and Biomedicine, Universität Leipzig, 04109 Leipzig, Germany
- Correspondence: (A.B.); (R.H.)
| | - Andor Krizsan
- Faculty of Chemistry and Mineralogy, Institute of Bioanalytical Chemistry, Universität Leipzig, 04109 Leipzig, Germany; (A.K.); (R.I.)
- Center for Biotechnology and Biomedicine, Universität Leipzig, 04109 Leipzig, Germany
| | - Renke Itzenga
- Faculty of Chemistry and Mineralogy, Institute of Bioanalytical Chemistry, Universität Leipzig, 04109 Leipzig, Germany; (A.K.); (R.I.)
- Center for Biotechnology and Biomedicine, Universität Leipzig, 04109 Leipzig, Germany
| | - Carl N. Kraus
- Aceragen Inc., Durham, NC 27709, USA; (C.N.K.); (L.O.J.)
| | - Laszlo Otvos
- Aceragen Inc., Durham, NC 27709, USA; (C.N.K.); (L.O.J.)
- Institute of Medical Microbiology, Semmelweis University, 1085 Budapest, Hungary
| | - Ralf Hoffmann
- Faculty of Chemistry and Mineralogy, Institute of Bioanalytical Chemistry, Universität Leipzig, 04109 Leipzig, Germany; (A.K.); (R.I.)
- Center for Biotechnology and Biomedicine, Universität Leipzig, 04109 Leipzig, Germany
- Correspondence: (A.B.); (R.H.)
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7
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Hamilton I, Gebala M, Herschlag D, Russell R. Direct Measurement of Interhelical DNA Repulsion and Attraction by Quantitative Cross-Linking. J Am Chem Soc 2022; 144:1718-1728. [PMID: 35073489 PMCID: PMC8815069 DOI: 10.1021/jacs.1c11122] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Indexed: 12/30/2022]
Abstract
To better understand the forces that mediate nucleic acid compaction in biology, we developed the disulfide cross-linking approach xHEED (X-linking of Helices to measure Electrostatic Effects at Distance) to measure the distance-dependent encounter frequency of two DNA helices in solution. Using xHEED, we determined the distance that the electrostatic potential extends from DNA helices, the dependence of this distance on ionic conditions, and the magnitude of repulsion when two helices approach one another. Across all conditions tested, the potential falls to that of the bulk solution within 15 Å of the major groove surface. For separations of ∼30 Å, we measured a repulsion of 1.8 kcal/mol in low monovalent ion concentration (30 mM Na+), with higher Na+ concentrations ameliorating this repulsion, and 2 M Na+ or 100 mM Mg2+ eliminating it. Strikingly, we found full screening at very low Co3+ concentrations and net attraction at higher concentrations, without the higher-order DNA condensation that typically complicates studies of helical attraction. Our measurements define the relevant distances for electrostatic interactions of nucleic-acid helices in biology and introduce a new method to propel further understanding of how these forces impact biological processes.
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Affiliation(s)
- Ian Hamilton
- Department
of Molecular Biosciences, University of
Texas at Austin, Austin, Texas 78712, United States
| | - Magdalena Gebala
- Department
of Biochemistry, Stanford University, Stanford California 94305, United States
| | - Daniel Herschlag
- Department
of Biochemistry, Stanford University, Stanford California 94305, United States
| | - Rick Russell
- Department
of Molecular Biosciences, University of
Texas at Austin, Austin, Texas 78712, United States
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8
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Burridge C, Waudby CA, Włodarski T, Cassaignau AME, Cabrita LD, Christodoulou J. Nascent chain dynamics and ribosome interactions within folded ribosome-nascent chain complexes observed by NMR spectroscopy. Chem Sci 2021; 12:13120-13126. [PMID: 34745542 PMCID: PMC8513902 DOI: 10.1039/d1sc04313g] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 09/09/2021] [Indexed: 12/24/2022] Open
Abstract
The folding of many proteins can begin during biosynthesis on the ribosome and can be modulated by the ribosome itself. Such perturbations are generally believed to be mediated through interactions between the nascent chain and the ribosome surface, but despite recent progress in characterising interactions of unfolded states with the ribosome, and their impact on the initiation of co-translational folding, a complete quantitative analysis of interactions across both folded and unfolded states of a nascent chain has yet to be realised. Here we apply solution-state NMR spectroscopy to measure transverse proton relaxation rates for methyl groups in folded ribosome-nascent chain complexes of the FLN5 filamin domain. We observe substantial increases in relaxation rates for the nascent chain relative to the isolated domain, which can be related to changes in effective rotational correlation times using measurements of relaxation and cross-correlated relaxation in the isolated domain. Using this approach, we can identify interactions between the nascent chain and the ribosome surface, driven predominantly by electrostatics, and by measuring the change in these interactions as the subsequent FLN6 domain emerges, we may deduce their impact on the free energy landscapes associated with the co-translational folding process.
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Affiliation(s)
- Charles Burridge
- Institute of Structural and Molecular Biology, University College London London WC1E 6BT UK
| | - Christopher A Waudby
- Institute of Structural and Molecular Biology, University College London London WC1E 6BT UK
| | - Tomasz Włodarski
- Institute of Structural and Molecular Biology, University College London London WC1E 6BT UK
| | - Anaïs M E Cassaignau
- Institute of Structural and Molecular Biology, University College London London WC1E 6BT UK
| | - Lisa D Cabrita
- Institute of Structural and Molecular Biology, University College London London WC1E 6BT UK
| | - John Christodoulou
- Institute of Structural and Molecular Biology, University College London London WC1E 6BT UK
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9
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Waudby CA, Burridge C, Christodoulou J. Optimal design of adaptively sampled NMR experiments for measurement of methyl group dynamics with application to a ribosome-nascent chain complex. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2021; 326:106937. [PMID: 33706222 PMCID: PMC7613274 DOI: 10.1016/j.jmr.2021.106937] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 01/25/2021] [Accepted: 02/05/2021] [Indexed: 05/14/2023]
Abstract
NMR measurements of cross-correlated nuclear spin relaxation provide powerful probes of polypeptide dynamics and rotational diffusion, free from contributions due to chemical exchange or interactions with external spins. Here, we report on the development of a sensitivity-optimized pulse sequence for the analysis of the differential relaxation of transitions within isolated 13CH3 spin systems, in order to characterise rotational diffusion and side chain order through the product S2τc. We describe the application of optimal design theory to implement a real-time 'on-the-fly' adaptive sampling scheme that maximizes the accuracy of the measured parameters. The increase in sensitivity obtained using this approach enables quantitative measurements of rotational diffusion within folded states of translationally-arrested ribosome-nascent chain complexes of the FLN5 filamin domain, and can be used to place strong limits on interactions between the domain and the ribosome surface.
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Affiliation(s)
- Christopher A Waudby
- Department of Structural and Molecular Biology, UCL, Gower St, London WC1E 6BT, UK.
| | - Charles Burridge
- Department of Structural and Molecular Biology, UCL, Gower St, London WC1E 6BT, UK
| | - John Christodoulou
- Department of Structural and Molecular Biology, UCL, Gower St, London WC1E 6BT, UK.
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Guo W, Xie Y, Lopez-Hernandez AE, Sun S, Li L. Electrostatic features for nucleocapsid proteins of SARS-CoV and SARS-CoV-2. MATHEMATICAL BIOSCIENCES AND ENGINEERING : MBE 2021; 18:2372-2383. [PMID: 33892550 PMCID: PMC8279046 DOI: 10.3934/mbe.2021120] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/24/2023]
Abstract
COVID-19 is increasingly affecting human health and global economy. Understanding the fundamental mechanisms of Severe Acute Respiratory Syndrome CoronaVirus 2 (SARS-CoV-2) is highly demanded to develop treatments for COVID-19. SARS-CoV and SARS-CoV-2 share 92.06% identity in their N protein RBDs' sequences, which results in very similar structures. However, the SARS-CoV-2 is more easily to spread. Utilizing multi-scale computational approaches, this work studied the fundamental mechanisms of the nucleocapsid (N) proteins of SARS-CoV and SARS-CoV-2, including their stabilities and binding strengths with RNAs at different pH values. Electrostatic potential on the surfaces of N proteins show that both the N proteins of SARS-CoV and SARS-CoV-2 have dominantly positive potential to attract RNAs. The binding forces between SARS-CoV N protein and RNAs at different distances are similar to that of SARS-CoV-2, both in directions and magnitudes. The electric filed lines between N proteins and RNAs are also similar for both SARS-CoV and SARS-CoV-2. The folding energy and binding energy dependence on pH revealed that the best environment for N proteins to perform their functions with RNAs is the weak acidic environment.
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Affiliation(s)
- Wenhan Guo
- Computational Science Program, University of Texas at El Paso, El Paso, TX 79968, USA
| | - Yixin Xie
- Computational Science Program, University of Texas at El Paso, El Paso, TX 79968, USA
| | | | - Shengjie Sun
- Computational Science Program, University of Texas at El Paso, El Paso, TX 79968, USA
| | - Lin Li
- Computational Science Program, University of Texas at El Paso, El Paso, TX 79968, USA
- Department of Physics, University of Texas at El Paso, El Paso, TX 79968, USA
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11
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Xie Y, Karki CB, Du D, Li H, Wang J, Sobitan A, Teng S, Tang Q, Li L. Spike Proteins of SARS-CoV and SARS-CoV-2 Utilize Different Mechanisms to Bind With Human ACE2. Front Mol Biosci 2020; 7:591873. [PMID: 33363207 PMCID: PMC7755986 DOI: 10.3389/fmolb.2020.591873] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 11/13/2020] [Indexed: 12/14/2022] Open
Abstract
The ongoing outbreak of COVID-19 has been a serious threat to human health worldwide. The virus SARS-CoV-2 initiates its infection to the human body via the interaction of its spike (S) protein with the human Angiotensin-Converting Enzyme 2 (ACE2) of the host cells. Therefore, understanding the fundamental mechanisms of how SARS-CoV-2 S protein receptor binding domain (RBD) binds to ACE2 is highly demanded for developing treatments for COVID-19. Here we implemented multi-scale computational approaches to study the binding mechanisms of human ACE2 and S proteins of both SARS-CoV and SARS-CoV-2. Electrostatic features, including electrostatic potential, electric field lines, and electrostatic forces of SARS-CoV and SARS-CoV-2 were calculated and compared in detail. The results demonstrate that SARS-CoV and SARS-CoV-2 S proteins are both attractive to ACE2 by electrostatic forces even at different distances. However, the residues contributing to the electrostatic features are quite different due to the mutations between SARS-CoV S protein and SARS-CoV-2 S protein. Such differences are analyzed comprehensively. Compared to SARS-CoV, the SARS-CoV-2 binds with ACE2 using a more robust strategy: The electric field line related residues are distributed quite differently, which results in a more robust binding strategy of SARS-CoV-2. Also, SARS-CoV-2 has a higher electric field line density than that of SARS-CoV, which indicates stronger interaction between SARS-CoV-2 and ACE2, compared to that of SARS-CoV. Key residues involved in salt bridges and hydrogen bonds are identified in this study, which may help the future drug design against COVID-19.
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Affiliation(s)
- Yixin Xie
- Computational Science Program, University of Texas at El Paso, El Paso, TX, United States
| | - Chitra B. Karki
- Computational Science Program, University of Texas at El Paso, El Paso, TX, United States
| | - Dan Du
- Computational Science Program, University of Texas at El Paso, El Paso, TX, United States
| | - Haotian Li
- Department of Physics, University of Texas at El Paso, El Paso, TX, United States
| | - Jun Wang
- Department of Physics, University of Texas at El Paso, El Paso, TX, United States
| | - Adebiyi Sobitan
- Department of Biology, Howard University, Washington, DC, United States
| | - Shaolei Teng
- Department of Biology, Howard University, Washington, DC, United States
| | - Qiyi Tang
- Department of Biology, Howard University, Washington, DC, United States
| | - Lin Li
- Computational Science Program, University of Texas at El Paso, El Paso, TX, United States,Department of Physics, University of Texas at El Paso, El Paso, TX, United States,*Correspondence: Lin Li
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