1
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Twarock R, Towers GJ, Stockley PG. Molecular frustration: a hypothesis for regulation of viral infections. Trends Microbiol 2024; 32:17-26. [PMID: 37507296 DOI: 10.1016/j.tim.2023.07.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 07/06/2023] [Accepted: 07/07/2023] [Indexed: 07/30/2023]
Abstract
The recent revolution in imaging techniques and results from RNA footprinting in situ reveal how the bacteriophage MS2 genome regulates both particle assembly and genome release. We have proposed a model in which multiple packaging signal (PS) RNA-coat protein (CP) contacts orchestrate different stages of a viral life cycle. Programmed formation and release of specific PS contacts with CP regulates viral particle assembly and genome uncoating during cell entry. We hypothesize that molecular frustration, a concept introduced to understand protein folding, can be used to better rationalize how PSs function in both particle assembly and genome release. More broadly this concept may explain the directionality of viral life cycles, for example, the roles of host cofactors in HIV infection. We propose that this is a universal principle in virology that explains mechanisms of host-virus interaction and suggests diverse therapeutic interventions.
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Affiliation(s)
- Reidun Twarock
- Departments of Mathematics and Biology & York Cross-Disciplinary Centre for Systems Analysis, University of York, York, UK
| | - Greg J Towers
- Division of Infection and Immunity, University College London, Gower Street, London WC1E 6BT, UK
| | - Peter G Stockley
- Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, LS2 9JT, UK.
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2
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González-Paz L, Lossada C, Hurtado-León ML, Fernández-Materán FV, Paz JL, Parvizi S, Cardenas Castillo RE, Romero F, Alvarado YJ. Intrinsic Dynamics of the ClpXP Proteolytic Machine Using Elastic Network Models. ACS OMEGA 2023; 8:7302-7318. [PMID: 36873006 PMCID: PMC9979342 DOI: 10.1021/acsomega.2c04347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/09/2022] [Accepted: 10/25/2022] [Indexed: 06/18/2023]
Abstract
ClpXP complex is an ATP-dependent mitochondrial matrix protease that binds, unfolds, translocates, and subsequently degrades specific protein substrates. Its mechanisms of operation are still being debated, and several have been proposed, including the sequential translocation of two residues (SC/2R), six residues (SC/6R), and even long-pass probabilistic models. Therefore, it has been suggested to employ biophysical-computational approaches that can determine the kinetics and thermodynamics of the translocation. In this sense, and based on the apparent inconsistency between structural and functional studies, we propose to apply biophysical approaches based on elastic network models (ENM) to study the intrinsic dynamics of the theoretically most probable hydrolysis mechanism. The proposed models ENM suggest that the ClpP region is decisive for the stabilization of the ClpXP complex, contributing to the flexibility of the residues adjacent to the pore, favoring the increase in pore size and, therefore, with the energy of interaction of its residues with a larger portion of the substrate. It is predicted that the complex may undergo a stable configurational change once assembled and that the deformability of the system once assembled is oriented, to increase the rigidity of the domains of each region (ClpP and ClpX) and to gain flexibility of the pore. Our predictions could suggest under the conditions of this study the mechanism of the interaction of the system, of which the substrate passes through the unfolding of the pore in parallel with a folding of the bottleneck. The variations in the distance calculated by molecular dynamics could allow the passage of a substrate with a size equivalent to ∼3 residues. The theoretical behavior of the pore and the stability and energy of binding to the substrate based on ENM models suggest that in this system, there are thermodynamic, structural, and configurational conditions that allow a possible translocation mechanism that is not strictly sequential.
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Affiliation(s)
- Lenin González-Paz
- Facultad
Experimental de Ciencias (FEC), Departamento de Biología, Laboratorio
de Genética y Biología Molecular (LGBM), Universidad del Zulia (LUZ), 4001 Maracaibo, Zulia, República Bolivariana
de Venezuela
- Centro
de Biomedicina Molecular (CBM). Laboratorio de Biocomputación
(LB), Instituto Venezolano de Investigaciones
Científicas (IVIC), 4001 Maracaibo, Zulia, República Bolivariana de Venezuela
| | - Carla Lossada
- Centro
de Biomedicina Molecular (CBM). Laboratorio de Biocomputación
(LB), Instituto Venezolano de Investigaciones
Científicas (IVIC), 4001 Maracaibo, Zulia, República Bolivariana de Venezuela
| | - Maria Laura Hurtado-León
- Facultad
Experimental de Ciencias (FEC), Departamento de Biología, Laboratorio
de Genética y Biología Molecular (LGBM), Universidad del Zulia (LUZ), 4001 Maracaibo, Zulia, República Bolivariana
de Venezuela
| | - Francelys V. Fernández-Materán
- Centro
de Biomedicina Molecular (CBM). Laboratorio de Biocomputación
(LB), Instituto Venezolano de Investigaciones
Científicas (IVIC), 4001 Maracaibo, Zulia, República Bolivariana de Venezuela
| | - José Luis Paz
- Departamento
Académico de Química Inorgánica, Facultad de
Química e Ingeniería Química, Universidad Nacional Mayor de San Marcos, 15081 Lima, Perú
| | - Shayan Parvizi
- Pulmonary,
Critical Care and Sleep Medicine, Baylor
College of Medicine, Houston, Texas 77030, United States
| | | | - Freddy Romero
- Pulmonary,
Critical Care and Sleep Medicine, Baylor
College of Medicine, Houston, Texas 77030, United States
| | - Ysaias J. Alvarado
- Centro
de Biomedicina Molecular (CBM), Laboratorio de Química Biofísica
Teórica y Experimental (LQBTE), Instituto
Venezolano de Investigaciones Cientificas (IVIC), 4001 Maracaibo, Zulia, República Bolivariana de Venezuela
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3
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Castelli M, Bhattacharya K, Abboud E, Serapian SA, Picard D, Colombo G. Phosphorylation of the Hsp90 Co-Chaperone Hop Changes its Conformational Dynamics and Biological Function. J Mol Biol 2023; 435:167931. [PMID: 36572238 DOI: 10.1016/j.jmb.2022.167931] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 12/16/2022] [Accepted: 12/16/2022] [Indexed: 12/25/2022]
Abstract
The molecular chaperones Hsp90 and Hsp70 and their regulatory co-chaperone Hop play a key role at the crossroads of the folding pathways of numerous client proteins by forming fine-tuned multiprotein complexes. Alterations of the biomolecules involved may functionally impact the chaperone machinery: here, we integrate simulations and experiments to unveil how Hop conformational fitness and interactions can be controlled by the perturbation of just one residue. Specifically, we unveil how mechanisms mediated by Hop residue Y354 control Hop open and closed states, which affect binding of Hsp70/Hsp90. Phosphorylation or mutation of Hop-Y354 are shown to favor structural ensembles that are indeed not optimal for stable interactions with Hsp90 and Hsp70. This disfavors cellular accumulation of the stringent Hsp90 clients glucocorticoid receptor and the viral tyrosine kinase v-Src, with detrimental effects on v-Src activity. Our results show how the post-translational modification of a specific residue in Hop provides a regulation mechanism for the larger chaperone complex of which it is part. In this framework, the effects of one single alteration are amplified at the cellular level through the perturbation of protein-interaction networks.
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Affiliation(s)
- Matteo Castelli
- Department of Chemistry, University of Pavia, Via Taramelli 12, 27100 Pavia, Italy. https://twitter.com/mat_castelli
| | - Kaushik Bhattacharya
- Department of Molecular and Cellular Biology, Université de Genève, Sciences III, 1211 Genève 4, Switzerland. https://twitter.com/kaushik34371359
| | - Ernest Abboud
- Department of Molecular and Cellular Biology, Université de Genève, Sciences III, 1211 Genève 4, Switzerland
| | - Stefano A Serapian
- Department of Chemistry, University of Pavia, Via Taramelli 12, 27100 Pavia, Italy
| | - Didier Picard
- Department of Molecular and Cellular Biology, Université de Genève, Sciences III, 1211 Genève 4, Switzerland.
| | - Giorgio Colombo
- Department of Chemistry, University of Pavia, Via Taramelli 12, 27100 Pavia, Italy.
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4
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Chen X, Chen M, Wolynes PG, Wittung-Stafshede P, Gray HB. Frustration Dynamics and Electron-Transfer Reorganization Energies in Wild-Type and Mutant Azurins. J Am Chem Soc 2022; 144:4178-4185. [PMID: 35171591 PMCID: PMC8915257 DOI: 10.1021/jacs.1c13454] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
![]()
Long-range electron
tunneling through metalloproteins is facilitated
by evolutionary tuning of donor–acceptor electronic couplings,
formal electrochemical potentials, and active-site reorganization
energies. Although the minimal frustration of the folding landscape
enables this tuning, residual frustration in the vicinity of the metallocofactor
can allow conformational fluctuations required for protein function.
We show here that the constrained copper site in wild-type azurin
is governed by an intricate pattern of minimally frustrated local
and distant interactions that together enable rapid electron flow
to and from the protein. In contrast, sluggish electron transfer reactions
(unfavorable reorganization energies) of active-site azurin variants
are attributable to increased frustration near to as well as distant
from the copper site, along with an exaggerated oxidation-state dependence
of both minimally and highly frustrated interaction patterns.
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Affiliation(s)
- Xun Chen
- Center for Theoretical Biological Physics, Houston, Texas 77005, United States.,Department of Chemistry, Rice University, Houston, Texas 77005, United States
| | - Mingchen Chen
- Center for Theoretical Biological Physics, Houston, Texas 77005, United States
| | - Peter G Wolynes
- Center for Theoretical Biological Physics, Houston, Texas 77005, United States.,Department of Chemistry, Rice University, Houston, Texas 77005, United States.,Department of Biosciences, Rice University, Houston, Texas 77005, United States
| | - Pernilla Wittung-Stafshede
- Department of Biology and Biological Engineering, Chalmers University of Technology, 412 96 Gothenburg, Sweden
| | - Harry B Gray
- Beckman Institute and Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
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5
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Nussinov R, Zhang M, Maloney R, Tsai CJ, Yavuz BR, Tuncbag N, Jang H. Mechanism of activation and the rewired network: New drug design concepts. Med Res Rev 2021; 42:770-799. [PMID: 34693559 PMCID: PMC8837674 DOI: 10.1002/med.21863] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 07/06/2021] [Accepted: 10/07/2021] [Indexed: 12/13/2022]
Abstract
Precision oncology benefits from effective early phase drug discovery decisions. Recently, drugging inactive protein conformations has shown impressive successes, raising the cardinal questions of which targets can profit and what are the principles of the active/inactive protein pharmacology. Cancer driver mutations have been established to mimic the protein activation mechanism. We suggest that the decision whether to target an inactive (or active) conformation should largely rest on the protein mechanism of activation. We next discuss the recent identification of double (multiple) same-allele driver mutations and their impact on cell proliferation and suggest that like single driver mutations, double drivers also mimic the mechanism of activation. We further suggest that the structural perturbations of double (multiple) in cis mutations may reveal new surfaces/pockets for drug design. Finally, we underscore the preeminent role of the cellular network which is deregulated in cancer. Our structure-based review and outlook updates the traditional Mechanism of Action, informs decisions, and calls attention to the intrinsic activation mechanism of the target protein and the rewired tumor-specific network, ushering innovative considerations in precision medicine.
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Affiliation(s)
- Ruth Nussinov
- Computational Structural Biology Section, Frederick National Laboratory for Cancer Research in the Laboratory of Cancer Immunometabolism, National Cancer Institute, Frederick, Maryland, USA.,Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Mingzhen Zhang
- Computational Structural Biology Section, Frederick National Laboratory for Cancer Research in the Laboratory of Cancer Immunometabolism, National Cancer Institute, Frederick, Maryland, USA
| | - Ryan Maloney
- Computational Structural Biology Section, Frederick National Laboratory for Cancer Research in the Laboratory of Cancer Immunometabolism, National Cancer Institute, Frederick, Maryland, USA
| | - Chung-Jung Tsai
- Computational Structural Biology Section, Frederick National Laboratory for Cancer Research in the Laboratory of Cancer Immunometabolism, National Cancer Institute, Frederick, Maryland, USA
| | - Bengi Ruken Yavuz
- Department of Health Informatics, Graduate School of Informatics, Middle East Technical University, Ankara, Turkey
| | - Nurcan Tuncbag
- Department of Health Informatics, Graduate School of Informatics, Middle East Technical University, Ankara, Turkey.,Department of Chemical and Biological Engineering, College of Engineering, Koc University, Istanbul, Turkey.,Koc University Research Center for Translational Medicine, School of Medicine, Koc University, Istanbul, Turkey
| | - Hyunbum Jang
- Computational Structural Biology Section, Frederick National Laboratory for Cancer Research in the Laboratory of Cancer Immunometabolism, National Cancer Institute, Frederick, Maryland, USA
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6
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Michael E, Simonson T. How much can physics do for protein design? Curr Opin Struct Biol 2021; 72:46-54. [PMID: 34461593 DOI: 10.1016/j.sbi.2021.07.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2021] [Revised: 07/22/2021] [Accepted: 07/25/2021] [Indexed: 01/03/2023]
Abstract
Physics and physical chemistry are an important thread in computational protein design, complementary to knowledge-based tools. They provide molecular mechanics scoring functions that need little or no ad hoc parameter readjustment, methods to thoroughly sample equilibrium ensembles, and different levels of approximation for conformational flexibility. They led recently to the successful redesign of a small protein using a physics-based folded state energy. Adaptive Monte Carlo or molecular dynamics schemes were discovered where protein variants are populated as per their ligand-binding free energy or catalytic efficiency. Molecular dynamics have been used for backbone flexibility. Implicit solvent models have been refined, polarizable force fields applied, and many physical insights obtained.
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Affiliation(s)
- Eleni Michael
- Laboratoire de Biologie Structurale de la Cellule (CNRS UMR7654), Ecole Polytechnique, 91128, Palaiseau, France
| | - Thomas Simonson
- Laboratoire de Biologie Structurale de la Cellule (CNRS UMR7654), Ecole Polytechnique, 91128, Palaiseau, France.
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7
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Hou Q, Pucci F, Ancien F, Kwasigroch JM, Bourgeas R, Rooman M. SWOTein: a structure-based approach to predict stability Strengths and Weaknesses of prOTEINs. Bioinformatics 2021; 37:1963–1971. [PMID: 33471089 DOI: 10.1093/bioinformatics/btab034] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 12/05/2020] [Accepted: 01/15/2021] [Indexed: 11/13/2022] Open
Abstract
MOTIVATION Although structured proteins adopt their lowest free energy conformation in physiological conditions, the individual residues are generally not in their lowest free energy conformation. Residues that are stability weaknesses are often involved in functional regions, whereas stability strengths ensure local structural stability. The detection of strengths and weaknesses provides key information to guide protein engineering experiments aiming to modulate folding and various functional processes. RESULTS We developed the SWOTein predictor which identifies strong and weak residues in proteins on the basis of three types of statistical energy functions describing local interactions along the chain, hydrophobic forces and tertiary interactions. The large-scale analysis of the different types of strengths and weaknesses demonstrated their complementarity and the enhancement of the information they provide. Moreover, a good average correlation was observed between predicted and experimental strengths and weaknesses obtained from native hydrogen exchange data. SWOTein application to three test cases further showed its suitability to predict and interpret strong and weak residues in the context of folding, conformational changes and protein-protein binding. In summary, SWOTein is both fast and accurate and can be applied at small and large scale to analyze and modulate folding and molecular recognition processes. AVAILABILITY The SWOTein webserver provides the list of predicted strengths and weaknesses and a protein structure visualization tool that facilitates the interpretation of the predictions. It is freely available for academic use at http://babylone.ulb.ac.be/SWOTein/.
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Affiliation(s)
- Qingzhen Hou
- Department of Biostatistics, School of Public Health, Cheeloo College of Medicine, Shandong University, Shandong 250002, P. R. China.,National Institute of Health Data Science of China, Shandong University, Shandong 250002, P. R. China.,Computational Biology and Bioinformatics, Université Libre de Bruxelles, Brussels 1050, Belgium
| | - Fabrizio Pucci
- Computational Biology and Bioinformatics, Université Libre de Bruxelles, Brussels 1050, Belgium.,Interuniversity Institute of Bioinformatics in Brussels, Boulevard du Triomphe, 1050 Brussels, Belgium
| | - François Ancien
- Computational Biology and Bioinformatics, Université Libre de Bruxelles, Brussels 1050, Belgium.,Interuniversity Institute of Bioinformatics in Brussels, Boulevard du Triomphe, 1050 Brussels, Belgium
| | - Jean-Marc Kwasigroch
- Computational Biology and Bioinformatics, Université Libre de Bruxelles, Brussels 1050, Belgium
| | - Raphaël Bourgeas
- Computational Biology and Bioinformatics, Université Libre de Bruxelles, Brussels 1050, Belgium
| | - Marianne Rooman
- Computational Biology and Bioinformatics, Université Libre de Bruxelles, Brussels 1050, Belgium.,Interuniversity Institute of Bioinformatics in Brussels, Boulevard du Triomphe, 1050 Brussels, Belgium
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8
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Chen M, Chen X, Jin S, Lu W, Lin X, Wolynes PG. Protein Structure Refinement Guided by Atomic Packing Frustration Analysis. J Phys Chem B 2020; 124:10889-10898. [PMID: 32931278 DOI: 10.1021/acs.jpcb.0c06719] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Recent advances in machine learning, bioinformatics, and the understanding of the folding problem have enabled efficient predictions of protein structures with moderate accuracy, even for targets where there is little information from templates. All-atom molecular dynamics simulations provide a route to refine such predicted structures, but unguided atomistic simulations, even when lengthy in time, often fail to eliminate incorrect structural features that would prevent the structure from becoming more energetically favorable owing to the necessity of making large scale motions and to overcoming energy barriers for side chain repacking. In this study, we show that localizing packing frustration at atomic resolution by examining the statistics of the energetic changes that occur when the local environment of a site is changed allows one to identify the most likely locations of incorrect contacts. The global statistics of atomic resolution frustration in structures that have been predicted using various algorithms provide strong indicators of structural quality when tested over a database of 20 targets from previous CASP experiments. Residues that are more correctly located turn out to be more minimally frustrated than more poorly positioned sites. These observations provide a diagnosis of both global and local quality of predicted structures and thus can be used as guidance in all-atom refinement simulations of the 20 targets. Refinement simulations guided by atomic packing frustration turn out to be quite efficient and significantly improve the quality of the structures.
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Affiliation(s)
- Mingchen Chen
- Center for Theoretical Biological Physics, Rice University, Houston, Texas 77005, United States
| | - Xun Chen
- Center for Theoretical Biological Physics, Rice University, Houston, Texas 77005, United States.,Department of Chemistry, Rice University, Houston, Texas 77005, United States
| | - Shikai Jin
- Center for Theoretical Biological Physics, Rice University, Houston, Texas 77005, United States.,Department of Biosciences, Rice University, Houston, Texas 77005, United States
| | - Wei Lu
- Center for Theoretical Biological Physics, Rice University, Houston, Texas 77005, United States.,Department of Physics and Astronomy, Rice University, Houston, Texas 77030, United States
| | - Xingcheng Lin
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Peter G Wolynes
- Center for Theoretical Biological Physics, Rice University, Houston, Texas 77005, United States.,Department of Chemistry, Rice University, Houston, Texas 77005, United States.,Department of Biosciences, Rice University, Houston, Texas 77005, United States.,Department of Physics and Astronomy, Rice University, Houston, Texas 77030, United States
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9
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Chen M, Chen X, Schafer NP, Clementi C, Komives EA, Ferreiro DU, Wolynes PG. Surveying biomolecular frustration at atomic resolution. Nat Commun 2020; 11:5944. [PMID: 33230150 PMCID: PMC7683549 DOI: 10.1038/s41467-020-19560-9] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 10/13/2020] [Indexed: 01/12/2023] Open
Abstract
To function, biomolecules require sufficient specificity of interaction as well as stability to live in the cell while still being able to move. Thermodynamic stability of only a limited number of specific structures is important so as to prevent promiscuous interactions. The individual interactions in proteins, therefore, have evolved collectively to give funneled minimally frustrated landscapes but some strategic parts of biomolecular sequences located at specific sites in the structure have been selected to be frustrated in order to allow both motion and interaction with partners. We describe a framework efficiently to quantify and localize biomolecular frustration at atomic resolution by examining the statistics of the energy changes that occur when the local environment of a site is changed. The location of patches of highly frustrated interactions correlates with key biological locations needed for physiological function. At atomic resolution, it becomes possible to extend frustration analysis to protein-ligand complexes. At this resolution one sees that drug specificity is correlated with there being a minimally frustrated binding pocket leading to a funneled binding landscape. Atomistic frustration analysis provides a route for screening for more specific compounds for drug discovery. The analysis of biomolecular frustration yielded insights into several aspects of protein behavior. Here the authors describe a framework to efficiently quantify and localize biomolecular frustration within proteins at atomic resolution, and observe that drug specificity is correlated with a minimally frustrated binding pocket leading to a funneled binding landscape.
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Affiliation(s)
- Mingchen Chen
- Center for Theoretical Biological Physics, Rice University, Houston, TX, USA
| | - Xun Chen
- Center for Theoretical Biological Physics, Department of Chemistry, Rice University, Houston, TX, USA
| | - Nicholas P Schafer
- Center for Theoretical Biological Physics, Department of Chemistry, Rice University, Houston, TX, USA
| | - Cecilia Clementi
- Center for Theoretical Biological Physics, Department of Chemistry, Rice University, Houston, TX, USA
| | - Elizabeth A Komives
- Department of Chemistry and Biochemistry, University of California at San Diego, La Jolla, CA, USA
| | - Diego U Ferreiro
- Protein Physiology Laboratory, University of Buenos Aires, Buenos Aires, Argentina
| | - Peter G Wolynes
- Center for Theoretical Biological Physics, Department of Chemistry, Rice University, Houston, TX, USA. .,Department of Biosciences, Rice University, Houston, TX, USA.
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10
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Jin S, Miller MD, Chen M, Schafer NP, Lin X, Chen X, Phillips GN, Wolynes PG. Molecular-replacement phasing using predicted protein structures from AWSEM-Suite. IUCRJ 2020; 7:1168-1178. [PMID: 33209327 PMCID: PMC7642774 DOI: 10.1107/s2052252520013494] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 10/07/2020] [Indexed: 06/11/2023]
Abstract
The phase problem in X-ray crystallography arises from the fact that only the intensities, and not the phases, of the diffracting electromagnetic waves are measured directly. Molecular replacement can often estimate the relative phases of reflections starting with those derived from a template structure, which is usually a previously solved structure of a similar protein. The key factor in the success of molecular replacement is finding a good template structure. When no good solved template exists, predicted structures based partially on templates can sometimes be used to generate models for molecular replacement, thereby extending the lower bound of structural and sequence similarity required for successful structure determination. Here, the effectiveness is examined of structures predicted by a state-of-the-art prediction algorithm, the Associative memory, Water-mediated, Structure and Energy Model Suite (AWSEM-Suite), which has been shown to perform well in predicting protein structures in CASP13 when there is no significant sequence similarity to a solved protein or only very low sequence similarity to known templates. The performance of AWSEM-Suite structures in molecular replacement is discussed and the results show that AWSEM-Suite performs well in providing useful phase information, often performing better than I-TASSER-MR and the previous algorithm AWSEM-Template.
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Affiliation(s)
- Shikai Jin
- Center for Theoretical Biological Physics, Rice University, Houston, Texas, USA
- Department of Biosciences, Rice University, Houston, Texas, USA
| | | | - Mingchen Chen
- Center for Theoretical Biological Physics, Rice University, Houston, Texas, USA
| | - Nicholas P. Schafer
- Center for Theoretical Biological Physics, Rice University, Houston, Texas, USA
- Department of Chemistry, Rice University, Houston, Texas, USA
| | - Xingcheng Lin
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Xun Chen
- Center for Theoretical Biological Physics, Rice University, Houston, Texas, USA
- Department of Chemistry, Rice University, Houston, Texas, USA
| | - George N. Phillips
- Department of Biosciences, Rice University, Houston, Texas, USA
- Department of Chemistry, Rice University, Houston, Texas, USA
| | - Peter G. Wolynes
- Center for Theoretical Biological Physics, Rice University, Houston, Texas, USA
- Department of Biosciences, Rice University, Houston, Texas, USA
- Department of Chemistry, Rice University, Houston, Texas, USA
- Department of Physics, Rice University, Houston, Texas, USA
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11
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Meli M, Morra G, Colombo G. Simple Model of Protein Energetics To Identify Ab Initio Folding Transitions from All-Atom MD Simulations of Proteins. J Chem Theory Comput 2020; 16:5960-5971. [PMID: 32693598 PMCID: PMC8009504 DOI: 10.1021/acs.jctc.0c00524] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
![]()
A fundamental
requirement to predict the native conformation, address
questions of sequence design and optimization, and gain insights into
the folding mechanisms of proteins lies in the definition of an unbiased
reaction coordinate that reports on the folding state without the
need to compare it to reference values, which might be unavailable
for new (designed) sequences. Here, we introduce such a reaction coordinate,
which does not depend on previous structural knowledge of the native
state but relies solely on the energy partition within the protein:
the spectral gap of the pair nonbonded energy matrix (ENergy Gap,
ENG). This quantity can be simply calculated along unbiased MD trajectories.
We show that upon folding the gap increases significantly, while its
fluctuations are reduced to a minimum. This is consistently observed
for a diverse set of systems and trajectories. Our approach allows
one to promptly identify residues that belong to the folding core
as well as residues involved in non-native contacts that need to be
disrupted to guide polypeptides to the folded state. The energy gap
and fluctuations criteria are then used to develop an automatic detection
system which allows us to extract and analyze folding transitions
from a generic MD trajectory. We speculate that our method can be
used to detect conformational ensembles in dynamic and intrinsically
disordered proteins, revealing potential preorganization for binding.
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Affiliation(s)
| | - Giulia Morra
- SCITEC-CNR, Via Mario Bianco 9, Milano 20131, Italy.,Weill-Cornell Medicine, 1300 York Avenue, New York, New York 10065, United States
| | - Giorgio Colombo
- SCITEC-CNR, Via Mario Bianco 9, Milano 20131, Italy.,University of Pavia, Department of Chemistry, Viale Taramelli 12, Pavia 27100, Italy
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