1
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Soleymani F, Paquet E, Viktor HL, Michalowski W. Structure-based protein and small molecule generation using EGNN and diffusion models: A comprehensive review. Comput Struct Biotechnol J 2024; 23:2779-2797. [PMID: 39050782 PMCID: PMC11268121 DOI: 10.1016/j.csbj.2024.06.021] [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: 04/19/2024] [Revised: 06/13/2024] [Accepted: 06/18/2024] [Indexed: 07/27/2024] Open
Abstract
Recent breakthroughs in deep learning have revolutionized protein sequence and structure prediction. These advancements are built on decades of protein design efforts, and are overcoming traditional time and cost limitations. Diffusion models, at the forefront of these innovations, significantly enhance design efficiency by automating knowledge acquisition. In the field of de novo protein design, the goal is to create entirely novel proteins with predetermined structures. Given the arbitrary positions of proteins in 3-D space, graph representations and their properties are widely used in protein generation studies. A critical requirement in protein modelling is maintaining spatial relationships under transformations (rotations, translations, and reflections). This property, known as equivariance, ensures that predicted protein characteristics adapt seamlessly to changes in orientation or position. Equivariant graph neural networks offer a solution to this challenge. By incorporating equivariant graph neural networks to learn the score of the probability density function in diffusion models, one can generate proteins with robust 3-D structural representations. This review examines the latest deep learning advancements, specifically focusing on frameworks that combine diffusion models with equivariant graph neural networks for protein generation.
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Affiliation(s)
- Farzan Soleymani
- Telfer School of Management, University of Ottawa, ON, K1N 6N5, Canada
| | - Eric Paquet
- National Research Council, 1200 Montreal Road, Ottawa, ON, K1A 0R6, Canada
- School of Electrical Engineering and Computer Science, University of Ottawa, ON, K1N 6N5, Canada
| | - Herna Lydia Viktor
- School of Electrical Engineering and Computer Science, University of Ottawa, ON, K1N 6N5, Canada
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2
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Xu G, Luo Z, Yan Y, Wang Q, Ma J. OPUS-Rota5: A highly accurate protein side-chain modeling method with 3D-Unet and RotaFormer. Structure 2024; 32:1001-1010.e2. [PMID: 38657613 DOI: 10.1016/j.str.2024.03.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Revised: 02/06/2024] [Accepted: 03/28/2024] [Indexed: 04/26/2024]
Abstract
Accurate protein side-chain modeling is crucial for protein folding and design. This is particularly true for molecular docking as ligands primarily interact with side chains. In this study, we introduce a two-stage side-chain modeling approach called OPUS-Rota5. It leverages a modified 3D-Unet to capture the local environmental features, including ligand information of each residue, and then employs the RotaFormer module to aggregate various types of features. Evaluation on three test sets, including recently released targets from CAMEO and CASP15, shows that OPUS-Rota5 significantly outperforms some other leading side-chain modeling methods. We also employ OPUS-Rota5 to refine the side chains of 25 G protein-coupled receptor targets predicted by AlphaFold2 and achieve a significantly improved success rate in a subsequent "back" docking of their natural ligands. Therefore, OPUS-Rota5 is a useful and effective tool for molecular docking, particularly for targets with relatively accurate predicted backbones but not side chains such as high-homology targets.
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Affiliation(s)
- Gang Xu
- Multiscale Research Institute of Complex Systems, Fudan University, Shanghai 200433, China; Zhangjiang Fudan International Innovation Center, Fudan University, Shanghai 201210, China; Shanghai AI Laboratory, Shanghai 200030, China
| | - Zhenwei Luo
- Multiscale Research Institute of Complex Systems, Fudan University, Shanghai 200433, China; Zhangjiang Fudan International Innovation Center, Fudan University, Shanghai 201210, China; Shanghai AI Laboratory, Shanghai 200030, China
| | - Yaming Yan
- Multiscale Research Institute of Complex Systems, Fudan University, Shanghai 200433, China; Zhangjiang Fudan International Innovation Center, Fudan University, Shanghai 201210, China
| | - Qinghua Wang
- Center for Biomolecular Innovation, Harcam Biomedicines, Shanghai 200131, China
| | - Jianpeng Ma
- Multiscale Research Institute of Complex Systems, Fudan University, Shanghai 200433, China; Zhangjiang Fudan International Innovation Center, Fudan University, Shanghai 201210, China; Shanghai AI Laboratory, Shanghai 200030, China.
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3
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Wu KE, Yang KK, van den Berg R, Alamdari S, Zou JY, Lu AX, Amini AP. Protein structure generation via folding diffusion. Nat Commun 2024; 15:1059. [PMID: 38316764 PMCID: PMC10844308 DOI: 10.1038/s41467-024-45051-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Accepted: 01/12/2024] [Indexed: 02/07/2024] Open
Abstract
The ability to computationally generate novel yet physically foldable protein structures could lead to new biological discoveries and new treatments targeting yet incurable diseases. Despite recent advances in protein structure prediction, directly generating diverse, novel protein structures from neural networks remains difficult. In this work, we present a diffusion-based generative model that generates protein backbone structures via a procedure inspired by the natural folding process. We describe a protein backbone structure as a sequence of angles capturing the relative orientation of the constituent backbone atoms, and generate structures by denoising from a random, unfolded state towards a stable folded structure. Not only does this mirror how proteins natively twist into energetically favorable conformations, the inherent shift and rotational invariance of this representation crucially alleviates the need for more complex equivariant networks. We train a denoising diffusion probabilistic model with a simple transformer backbone and demonstrate that our resulting model unconditionally generates highly realistic protein structures with complexity and structural patterns akin to those of naturally-occurring proteins. As a useful resource, we release an open-source codebase and trained models for protein structure diffusion.
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Affiliation(s)
- Kevin E Wu
- Department of Computer Science, Stanford University, Stanford, CA, USA
- Center for Personal Dynamic Regulomes, Stanford University, Stanford, CA, USA
- Department of Biomedical Data Science, Stanford University School of Medicine, Stanford, CA, USA
| | | | | | | | - James Y Zou
- Department of Computer Science, Stanford University, Stanford, CA, USA
- Department of Biomedical Data Science, Stanford University School of Medicine, Stanford, CA, USA
| | - Alex X Lu
- Microsoft Research, Cambridge, MA, USA
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4
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Randolph NZ, Kuhlman B. Invariant point message passing for protein side chain packing. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.03.551328. [PMID: 38187664 PMCID: PMC10769188 DOI: 10.1101/2023.08.03.551328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2024]
Abstract
Protein side chain packing (PSCP) is a fundamental problem in the field of protein engineering, as high-confidence and low-energy conformations of amino acid side chains are crucial for understanding (and designing) protein folding, protein-protein interactions, and protein-ligand interactions. Traditional PSCP methods (such as the Rosetta Packer) often rely on a library of discrete side chain conformations, or rotamers, and a forcefield to guide the structure to low-energy conformations. Recently, deep learning (DL) based methods (such as DLPacker, AttnPacker, and DiffPack) have demonstrated state-of-the-art predictions and speed in the PSCP task. Building off the success of geometric graph neural networks for protein modeling, we present the Protein Invariant Point Packer (PIPPack) which effectively processes local structural and sequence information to produce realistic, idealized side chain coordinates using χ-angle distribution predictions and geometry-aware invariant point message passing (IPMP). On a test set of ~1,400 high-quality protein chains, PIPPack is highly competitive with other state-of-the-art PSCP methods in rotamer recovery and per-residue RMSD but is significantly faster.
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Affiliation(s)
- Nicholas Z Randolph
- Department of Bioinformatics and Computational Biology, University of North Carolina School of Medicine, Chapel Hill, North Carolina, USA
- Department of Biochemistry and Biophysics, University of North Carolina School of Medicine, Chapel Hill, North Carolina, USA
| | - Brian Kuhlman
- Department of Bioinformatics and Computational Biology, University of North Carolina School of Medicine, Chapel Hill, North Carolina, USA
- Department of Biochemistry and Biophysics, University of North Carolina School of Medicine, Chapel Hill, North Carolina, USA
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5
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Petrovskiy DV, Nikolsky KS, Rudnev VR, Kulikova LI, Butkova TV, Malsagova KA, Kopylov AT, Kaysheva AL. Modeling Side Chains in the Three-Dimensional Structure of Proteins for Post-Translational Modifications. Int J Mol Sci 2023; 24:13431. [PMID: 37686234 PMCID: PMC10488155 DOI: 10.3390/ijms241713431] [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: 08/08/2023] [Revised: 08/23/2023] [Accepted: 08/28/2023] [Indexed: 09/10/2023] Open
Abstract
Amino acid substitutions and post-translational modifications (PTMs) play a crucial role in many cellular processes by directly affecting the structural and dynamic features of protein interaction. Despite their importance, the understanding of protein PTMs at the structural level is still largely incomplete. The Protein Data Bank contains a relatively small number of 3D structures having post-translational modifications. Although recent years have witnessed significant progress in three-dimensional modeling (3D) of proteins using neural networks, the problem related to predicting accurate PTMs in proteins has been largely ignored. Predicting accurate 3D PTM models in proteins is closely related to another fundamental problem: predicting the correct side-chain conformations of amino acid residues in proteins. An analysis of publications as well as the paid and free software packages for modeling three-dimensional structures showed that most of them focus on working with unmodified proteins and canonical amino acid residues; the number of articles and software packages placing emphasis on modeling three-dimensional PTM structures is an order of magnitude smaller. This paper focuses on modeling the side-chain conformations of proteins containing PTMs (nonstandard amino acid residues). We collected our own libraries comprising the most frequently observed PTMs from the PDB and implemented a number of algorithms for predicting the side-chain conformation at modification points and in the immediate environment of the protein. A comprehensive analysis of both the algorithms per se and compared to the common Rosetta and FoldX structure modeling packages was also carried out. The proposed algorithmic solutions are comparable in their characteristics to the well-known Rosetta and FoldX packages for the modeling of three-dimensional structures and have great potential for further development and optimization. The source code of algorithmic solutions has been deposited to and is available at the GitHub source.
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Affiliation(s)
| | | | | | | | | | - Kristina A. Malsagova
- Institute of Biomedical Chemistry, 119121 Moscow, Russia; (D.V.P.); (K.S.N.); (V.R.R.); (L.I.K.); (T.V.B.); (A.T.K.); (A.L.K.)
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6
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Tessmer MH, Stoll S. chiLife: An open-source Python package for in silico spin labeling and integrative protein modeling. PLoS Comput Biol 2023; 19:e1010834. [PMID: 37000838 PMCID: PMC10096462 DOI: 10.1371/journal.pcbi.1010834] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 04/12/2023] [Accepted: 03/16/2023] [Indexed: 04/03/2023] Open
Abstract
Here we introduce chiLife, a Python package for site-directed spin label (SDSL) modeling for electron paramagnetic resonance (EPR) spectroscopy, in particular double electron-electron resonance (DEER). It is based on in silico attachment of rotamer ensemble representations of spin labels to protein structures. chiLife enables the development of custom protein analysis and modeling pipelines using SDSL EPR experimental data. It allows the user to add custom spin labels, scoring functions and spin label modeling methods. chiLife is designed with integration into third-party software in mind, to take advantage of the diverse and rapidly expanding set of molecular modeling tools available with a Python interface. This article describes the main design principles of chiLife and presents a series of examples.
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Affiliation(s)
- Maxx H. Tessmer
- Department of Chemistry, University of Washington, Seattle, Washington United States of America
| | - Stefan Stoll
- Department of Chemistry, University of Washington, Seattle, Washington United States of America
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7
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Khanfar MA, Salaas N, Abumostafa R. Discovery of natural-derived M pro inhibitors as therapeutic candidates for COVID-19: Structure-based pharmacophore screening combined with QSAR analysis. Mol Inform 2023; 42:e2200198. [PMID: 36762567 DOI: 10.1002/minf.202200198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2022] [Revised: 12/26/2022] [Accepted: 01/05/2023] [Indexed: 02/11/2023]
Abstract
The main protease (Mpro ) is an essential enzyme for the life cycle of SARS-CoV-2 and a validated target for treatment of COVID-19 infection. Structure-based pharmacophore modeling combined with QSAR calculations were employed to identify new chemical scaffolds of Mpro inhibitors from natural products repository. Hundreds of pharmacophore models were manually built from their corresponding X-ray crystallographic structures. A pharmacophore model that was validated by receiver operating characteristic (ROC) curve analysis and selected using the statistically optimum QSAR equation was implemented as a 3D-search tool to mine AnalytiCon Discovery database of natural products. Captured hits that showed the highest predicted inhibitory activities were bioassayed. Three active Mpro inhibitors (pseurotin A, lactupicrin, and alpinetin) were successfully identified with IC50 values in low micromolar range.
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Affiliation(s)
- Mohammad A Khanfar
- College of Pharmacy, Alfaisal University, Al Takhassusi Rd, P. O. Box 50927, Riyadh, 11533, Saudi Arabia.,Department of Pharmaceutical Sciences, Faculty of Pharmacy, The University of Jordan, P.O Box 13140, Amman, 11942, Jordan
| | - Nada Salaas
- College of Pharmacy, Alfaisal University, Al Takhassusi Rd, P. O. Box 50927, Riyadh, 11533, Saudi Arabia
| | - Reem Abumostafa
- College of Pharmacy, Alfaisal University, Al Takhassusi Rd, P. O. Box 50927, Riyadh, 11533, Saudi Arabia
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8
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Hassan M, Coutsias EA. Kinematic Reconstruction of Cyclic Peptides and Protein Backbones from Partial Data. J Chem Inf Model 2021; 61:4975-5000. [PMID: 34570494 PMCID: PMC10129052 DOI: 10.1021/acs.jcim.1c00453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We present an algorithm, QBKR (Quaternary Backbone Kinematic Reconstruction), a fast analytical method for an all-atom backbone reconstruction of proteins and linear or cyclic peptide chains from Cα coordinate traces. Unlike previous analytical methods for deriving all-atom representations from coarse-grained models that rely on canonical geometry with planar peptides in the trans conformation, our de novo kinematic model incorporates noncanonical, cis-trans, geometry naturally. Perturbations to this geometry can be effected with ease in our formulation, for example, to account for a continuous change from cis to trans geometry. A simple optimization of a spring-based objective function is employed for Cα-Cα distance variations that extend beyond the cis-trans limit. The kinematic construction produces a linked chain of peptide units, Cα-C-N-Cα, hinged at the Cα atoms spanning all possible planar and nonplanar peptide conformations. We have combined our method with a ring closure algorithm for the case of ring peptides and missing loops in a protein structure. Here, the reconstruction proceeding from both the N and C termini of the protein backbone (or in both directions from a starting position for rings) requires freedom in the position of one Cα atom (a capstone) to achieve a successful loop or ring closure. A salient feature of our reconstruction method is the ability to enrich conformational ensembles to produce alternative feasible conformations in which H-bond forming C-O or N-H pairs in the backbone can reverse orientations, thus addressing a well-known shortcoming in Cα-based RMSD structure comparison, wherein very close structures may lead to significantly different overall H-bond behavior. We apply the fixed Cα-based design to the reverse reconstruction from noisy Cryo-EM data, a posteriori to the optimization. Our method can be applied to speed up the process of an all-atom description from voluminous experimental data or subpar electron density maps.
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Affiliation(s)
- Mosavverul Hassan
- Department of Applied Mathematics and Statistics, Stony Brook University, Stony Brook, New York 11794, United States
| | - Evangelos A Coutsias
- Department of Applied Mathematics and Statistics, Stony Brook University, Stony Brook, New York 11794, United States.,Laufer Center for Physical and Quantitative Biology, Stony Brook University, Stony Brook, New York 11794-5252, United States
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9
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Patidar M, Yadav N, Dalai SK. Development of Stable Chimeric IL-15 for Trans-Presentation by the Antigen Presenting Cells. Front Immunol 2021; 12:646159. [PMID: 33953717 PMCID: PMC8092395 DOI: 10.3389/fimmu.2021.646159] [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: 12/25/2020] [Accepted: 03/15/2021] [Indexed: 11/23/2022] Open
Abstract
IL-15 is one of the important biologics considered for vaccine adjuvant and treatment of cancer. However, a short half-life and poor bioavailability limit its therapeutic potential. Herein, we have structured IL-15 into a chimeric protein to improve its half-life enabling greater bioavailability for longer periods. We have covalently linked IL-15 with IgG2 base to make the IL-15 a stable chimeric protein, which also increased its serum half-life by 40 fold. The dimeric structure of this kind of IgG based biologics has greater stability, resistance to proteolytic cleavage, and less frequent dosing schedule with minimum dosage for achieving the desired response compared to that of their monomeric forms. The structured chimeric IL-15 naturally forms a dimer, and retains its affinity for binding to its receptor, IL-15Rβ. Moreover, with the focused action of the structured chimeric IL-15, antigen-presenting cells (APC) would transpresent chimeric IL-15 along with antigen to the T cell, that will help the generation of quantitatively and qualitatively better antigen-specific memory T cells. In vitro and in vivo studies demonstrate the biological activity of chimeric IL-15 with respect to its ability to induce IL-15 signaling and modulating CD8+ T cell response in favor of memory generation. Thus, a longer half-life, dimeric nature, and anticipated focused transpresentation by APCs to the T cells will make chimeric IL-15 a super-agonist for memory CD8+ T cell responses.
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Affiliation(s)
- Manoj Patidar
- Institute of Science, Nirma University, Ahmedabad, India.,Department of Zoology, Govt. College Manawar, Dhar, India
| | - Naveen Yadav
- Institute of Science, Nirma University, Ahmedabad, India.,Translation Health Science and Technology Institute, NCR-Biotech Science Cluster, Faridabad, India
| | - Sarat K Dalai
- Institute of Science, Nirma University, Ahmedabad, India
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10
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Abstract
We investigate aspects of topology in protein folding. For this we numerically simulate the temperature driven folding and unfolding of the slipknotted archaeal virus protein AFV3-109. Due to knottiness the (un)folding is a topological process, it engages the entire backbone in a collective fashion. Accordingly we introduce a topological approach to model the process. Our simulations reveal that the (un)folding of AFV3-109 slipknot proceeds through a folding intermediate that has the topology of a trefoil knot. We observe that the final slipknot causes a slight swelling of the folded AFV3-109 structure. We disclose the relative stability of the strands and helices during both the folding and unfolding processes. We confirm results from previous studies that pointed out that it can be very demanding to simulate the formation of knotty self-entanglement, and we explain how the problems are circumvented: The slipknotted AFV3-109 protein is a very slow folder with a topologically demanding pathway, which needs to be properly accounted for in a simulation description. When we either increase the relative stiffness of bending, or when we decrease the speed of ambient cooling, the rate of slipknot formation rapidly increases.
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11
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Toropova AP, Toropov AA. Application of the Monte Carlo Method for the Prediction of Behavior of Peptides. Curr Protein Pept Sci 2019; 20:1151-1157. [DOI: 10.2174/1389203720666190123163907] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Revised: 12/17/2018] [Accepted: 12/20/2018] [Indexed: 12/26/2022]
Abstract
Prediction of physicochemical and biochemical behavior of peptides is an important and attractive
task of the modern natural sciences, since these substances have a key role in life processes. The
Monte Carlo technique is a possible way to solve the above task. The Monte Carlo method is a tool with
different applications relative to the study of peptides: (i) analysis of the 3D configurations (conformers);
(ii) establishment of quantitative structure – property / activity relationships (QSPRs/QSARs); and (iii)
development of databases on the biopolymers. Current ideas related to application of the Monte Carlo
technique for studying peptides and biopolymers have been discussed in this review.
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Affiliation(s)
- Alla P. Toropova
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Via La Masa 19, 20156 Milano, Italy
| | - Andrey A. Toropov
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Via La Masa 19, 20156 Milano, Italy
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12
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Begun A, Molochkov A, Niemi AJ. Protein tertiary structure and the myoglobin phase diagram. Sci Rep 2019; 9:10819. [PMID: 31346242 PMCID: PMC6658483 DOI: 10.1038/s41598-019-47317-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Accepted: 07/11/2019] [Indexed: 02/06/2023] Open
Abstract
We develop an effective theory approach to investigate the phase properties of globular proteins. Instead of interactions between individual atoms or localized interaction centers, the approach builds directly on the tertiary structure of a protein. As an example we construct the phase diagram of (apo)myoglobin with temperature (T) and acidity (pH) as the thermodynamical variables. We describe how myoglobin unfolds from the native folded state to a random coil when temperature and acidity increase. We confirm the presence of two molten globule folding intermediates, and we predict an abrupt transition between the two when acidity changes. When temperature further increases we find that the abrupt transition line between the two molten globule states terminates at a tricritical point, where the helical structures fade away. Our results also suggest that the ligand entry and exit is driven by large scale collective motions that destabilize the myoglobin F-helix.
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Affiliation(s)
- Alexander Begun
- Laboratory of Physics of Living Matter, Far Eastern Federal University, 690950, Sukhanova 8, Vladivostok, Russia
| | - Alexander Molochkov
- Laboratory of Physics of Living Matter, Far Eastern Federal University, 690950, Sukhanova 8, Vladivostok, Russia
| | - Antti J Niemi
- Laboratory of Physics of Living Matter, Far Eastern Federal University, 690950, Sukhanova 8, Vladivostok, Russia.
- Nordita, Stockholm University, Roslagstullsbacken 23, SE-106 91, Stockholm, Sweden.
- Institut Denis Poisson, CNRS UMR 7013, Parc de Grandmont, F37200, Tours, France.
- Department of Physics, Beijing Institute of Technology, Haidian District, Beijing, 100081, People's Republic of China.
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13
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Chojnacki S, Cowley A, Lee J, Foix A, Lopez R. Programmatic access to bioinformatics tools from EMBL-EBI update: 2017. Nucleic Acids Res 2019; 45:W550-W553. [PMID: 28431173 PMCID: PMC5570243 DOI: 10.1093/nar/gkx273] [Citation(s) in RCA: 216] [Impact Index Per Article: 43.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Accepted: 04/05/2017] [Indexed: 01/25/2023] Open
Abstract
Since 2009 the EMBL-EBI provides free and unrestricted access to several bioinformatics tools via the user's browser as well as programmatically via Web Services APIs. Programmatic access to these tools, which is fundamental to bioinformatics, is increasingly important as more high-throughput data is generated, e.g. from proteomics and metagenomic experiments. Access is available using both the SOAP and RESTful approaches and their usage is reviewed regularly in order to ensure that the best, supported tools are available to all users. We present here an update describing the latest enhancement to the Job Dispatcher APIs as well as the governance under it.
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Affiliation(s)
- Szymon Chojnacki
- European Bioinformatics Institute, EMBL Outstation, Wellcome Trust Genome Campus, Hinxton, CB10 1SD Cambridge, UK
| | - Andrew Cowley
- European Bioinformatics Institute, EMBL Outstation, Wellcome Trust Genome Campus, Hinxton, CB10 1SD Cambridge, UK
| | - Joon Lee
- European Bioinformatics Institute, EMBL Outstation, Wellcome Trust Genome Campus, Hinxton, CB10 1SD Cambridge, UK
| | - Anna Foix
- European Bioinformatics Institute, EMBL Outstation, Wellcome Trust Genome Campus, Hinxton, CB10 1SD Cambridge, UK
| | - Rodrigo Lopez
- European Bioinformatics Institute, EMBL Outstation, Wellcome Trust Genome Campus, Hinxton, CB10 1SD Cambridge, UK
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14
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Liu J, Dai J, He J, Peng X, Niemi AJ. Can the geometry of all-atom protein trajectories be reconstructed from the knowledge of Cα time evolution? A study of peptide plane O and side chain Cβ atoms. J Chem Phys 2019; 150:225103. [PMID: 31202245 DOI: 10.1063/1.5082627] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We inquire to what extent can the geometry of protein peptide plane and side chain atoms be reconstructed from the knowledge of Cα time evolution. Due to the lack of experimental data, we analyze all atom molecular dynamics trajectories from the Anton supercomputer, and for clarity, we limit our attention to the peptide plane O atoms and side chain Cβ atoms. We reconstruct their positions using four different approaches. Three of these are the publicly available reconstruction programs Pulchra, Remo, and Scwrl4. The fourth, Statistical Method, builds entirely on the statistical analysis of Protein Data Bank structures. All four methods place the O and Cβ atoms accurately along the Anton trajectories; the Statistical Method gives results that are closest to the Anton data. The results suggest that when a protein moves under physiological conditions, its all atom structures can be reconstructed with high accuracy from the knowledge of the Cα atom positions. This can help to better understand and improve all atom force fields, and advance reconstruction and refinement methods for reduced protein structures. The results provide impetus for the development of effective coarse grained force fields in terms of reduced coordinates.
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Affiliation(s)
- Jiaojiao Liu
- School of Physics, Beijing Institute of Technology, Beijing 100081, People's Republic of China
| | - Jin Dai
- Nordita, Stockholm University, Roslagstullsbacken 23, SE-106 91 Stockholm, Sweden
| | - Jianfeng He
- School of Physics, Beijing Institute of Technology, Beijing 100081, People's Republic of China
| | - Xubiao Peng
- Center for Quantum Technology Research, School of Physics, Beijing Institute of Technology, Beijing 100081, People's Republic of China
| | - Antti J Niemi
- School of Physics, Beijing Institute of Technology, Beijing 100081, People's Republic of China
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15
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Hou Y, Liu J, He J, Peng X, Niemi AJ. Study of correlations between protein peptide plane dynamics and side chain dynamics. PLoS One 2019; 14:e0215141. [PMID: 30978222 PMCID: PMC6461237 DOI: 10.1371/journal.pone.0215141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Accepted: 03/27/2019] [Indexed: 11/18/2022] Open
Abstract
Protein dynamics is pivotal to biological processes. However, experiments are very demanding and difficult to perform, and all-atom molecular dynamics simulations can still not provide all the answers. This motivates us to analyze protein dynamics in terms of different reduced coordinate representations. We then need to resolve how to reconstruct the full all-atom dynamics from its coarse grained approximation. Accordingly we scrutinize all-atom molecular dynamics trajectories in terms of crystallographic Protein Data Bank (PDB) structures, and inquire to what extent is it possible to predict the dynamics of side chain Cβ atoms in terms of the static properties of backbone Cα and O atoms. Here we find that simulated Cβ dynamics at near physiological conditions can be reconstructed with very high precision, using the knowledge of the crystallographic backbone Cα and O positions. The precision we can reach with our PDB-based Statistical Method reconstruction exceeds that of popular all-atom reconstruction methods such as Remo and Pulchra, and is fully comparable with the precision of the highly elaborate Scwrl4 all-atom reconstruction method that we have enhanced with the knowledge of the backbone Cα and O atom positions. We then conclude that in a dynamical protein that moves around at physiological conditions, the relative positions of its Cβ atoms with respect to the backbone Cα and O atoms, deviate very little from their relative positions in static crystallographic PDB structures. This proposes that the dynamics of a biologically active protein could remain subject to very similar, stringent stereochemical constraints that dictate the structure of a folded crystallographic protein. Thus, our results provide a strong impetus to the development of coarse grained techniques that are based on reduced coordinate representations.
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Affiliation(s)
- Yanzhen Hou
- School of Physics, Beijing Institute of Technology, Beijing 100081, P.R. China
| | - Jiaojiao Liu
- School of Physics, Beijing Institute of Technology, Beijing 100081, P.R. China
| | - Jianfeng He
- School of Physics, Beijing Institute of Technology, Beijing 100081, P.R. China
| | - Xubiao Peng
- School of Physics, Beijing Institute of Technology, Beijing 100081, P.R. China
- Center for Quantum Technology Research and School of Physics, Beijing Institute of Technology, Beijing 100081, P.R. China
| | - Antti J. Niemi
- School of Physics, Beijing Institute of Technology, Beijing 100081, P.R. China
- Laboratoire de Mathematiques et Physique Theorique CNRS UMR 6083, Fédération Denis Poisson, Université de Tours, Parc de Grandmont, F37200, Tours, France
- Nordita, Stockholm University, Roslagstullsbacken 23, SE-106 91 Stockholm, Sweden
- Laboratory of Physics of Living Matter, Far Eastern Federal University, 690950, Sukhanova 8, Vladivostok, Russia
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16
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Loeffler TD, Chan H, Narayanan B, Cherukara MJ, Gray S, Sankaranarayanan SKRS. Configurational-Bias Monte Carlo Back-Mapping Algorithm for Efficient and Rapid Conversion of Coarse-Grained Water Structures into Atomistic Models. J Phys Chem B 2018; 122:7102-7110. [DOI: 10.1021/acs.jpcb.8b01791] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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17
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Kellogg EH, Hejab NMA, Poepsel S, Downing KH, DiMaio F, Nogales E. Near-atomic model of microtubule-tau interactions. Science 2018; 360:1242-1246. [PMID: 29748322 PMCID: PMC6225777 DOI: 10.1126/science.aat1780] [Citation(s) in RCA: 235] [Impact Index Per Article: 39.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Accepted: 04/30/2018] [Indexed: 12/20/2022]
Abstract
Tau is a developmentally regulated axonal protein that stabilizes and bundles microtubules (MTs). Its hyperphosphorylation is thought to cause detachment from MTs and subsequent aggregation into fibrils implicated in Alzheimer's disease. It is unclear which tau residues are crucial for tau-MT interactions, where tau binds on MTs, and how it stabilizes them. We used cryo-electron microscopy to visualize different tau constructs on MTs and computational approaches to generate atomic models of tau-tubulin interactions. The conserved tubulin-binding repeats within tau adopt similar extended structures along the crest of the protofilament, stabilizing the interface between tubulin dimers. Our structures explain the effect of phosphorylation on MT affinity and lead to a model of tau repeats binding in tandem along protofilaments, tethering together tubulin dimers and stabilizing polymerization interfaces.
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Affiliation(s)
- Elizabeth H Kellogg
- QB3 Institute and Department of Molecular and Cell Biology, University of California-Berkeley, Berkeley, CA 94720, USA
- Division of Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Nisreen M A Hejab
- Division of Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Simon Poepsel
- QB3 Institute and Department of Molecular and Cell Biology, University of California-Berkeley, Berkeley, CA 94720, USA
| | - Kenneth H Downing
- Division of Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Frank DiMaio
- Department of Biochemistry, University of Washington, Seattle, WA 98195, USA
- Institute for Protein Design, Seattle, WA 98195, USA
| | - Eva Nogales
- QB3 Institute and Department of Molecular and Cell Biology, University of California-Berkeley, Berkeley, CA 94720, USA.
- Division of Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
- Howard Hughes Medical Institute, University of California-Berkeley, Berkeley, CA 94720, USA
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18
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Thomas JMH, Simkovic F, Keegan R, Mayans O, Zhang C, Zhang Y, Rigden DJ. Approaches to ab initio molecular replacement of α-helical transmembrane proteins. Acta Crystallogr D Struct Biol 2017; 73:985-996. [PMID: 29199978 PMCID: PMC5713875 DOI: 10.1107/s2059798317016436] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Accepted: 11/15/2017] [Indexed: 02/06/2023] Open
Abstract
α-Helical transmembrane proteins are a ubiquitous and important class of proteins, but present difficulties for crystallographic structure solution. Here, the effectiveness of the AMPLE molecular replacement pipeline in solving α-helical transmembrane-protein structures is assessed using a small library of eight ideal helices, as well as search models derived from ab initio models generated both with and without evolutionary contact information. The ideal helices prove to be surprisingly effective at solving higher resolution structures, but ab initio-derived search models are able to solve structures that could not be solved with the ideal helices. The addition of evolutionary contact information results in a marked improvement in the modelling and makes additional solutions possible.
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Affiliation(s)
- Jens M. H. Thomas
- Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, England
| | - Felix Simkovic
- Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, England
| | - Ronan Keegan
- Research Complex at Harwell, STFC Rutherford Appleton Laboratory, Didcot OX11 0FA, England
| | - Olga Mayans
- Fachbereich Biologie, Universität Konstanz, D-78457 Konstanz, Germany
| | - Chengxin Zhang
- Department of Computational Medicine and Bioinformatics, Department of Biological Chemistry, Medical School, University of Michigan, 100 Washtenaw Avenue, Ann Arbor, MI 48109-2218, USA
| | - Yang Zhang
- Department of Computational Medicine and Bioinformatics, Department of Biological Chemistry, Medical School, University of Michigan, 100 Washtenaw Avenue, Ann Arbor, MI 48109-2218, USA
| | - Daniel J. Rigden
- Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, England
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19
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Kaschner M, Schillinger O, Fettweiss T, Nutschel C, Krause F, Fulton A, Strodel B, Stadler A, Jaeger KE, Krauss U. A combination of mutational and computational scanning guides the design of an artificial ligand-binding controlled lipase. Sci Rep 2017; 7:42592. [PMID: 28218303 PMCID: PMC5316958 DOI: 10.1038/srep42592] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 01/11/2017] [Indexed: 11/09/2022] Open
Abstract
Allostery, i.e. the control of enzyme activity by a small molecule at a location distant from the enzyme’s active site, represents a mechanism essential for sustaining life. The rational design of allostery is a non-trivial task but can be achieved by fusion of a sensory domain, which responds to environmental stimuli with a change in its structure. Hereby, the site of domain fusion is difficult to predict. We here explore the possibility to rationally engineer allostery into the naturally not allosterically regulated Bacillus subtilis lipase A, by fusion of the citrate-binding sensor-domain of the CitA sensory-kinase of Klebsiella pneumoniae. The site of domain fusion was rationally determined based on whole-protein site-saturation mutagenesis data, complemented by computational evolutionary-coupling analyses. Functional assays, combined with biochemical and biophysical studies suggest a mechanism for control, similar but distinct to the one of the parent CitA protein, with citrate acting as an indirect modulator of Triton-X100 inhibition of the fusion protein. Our study demonstrates that the introduction of ligand-dependent regulatory control by domain fusion is surprisingly facile, suggesting that the catalytic mechanism of some enzymes may be evolutionary optimized in a way that it can easily be perturbed by small conformational changes.
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Affiliation(s)
- Marco Kaschner
- Institut für Molekulare Enzymtechnologie, Heinrich-Heine Universität Düsseldorf, Forschungszentrum Jülich GmbH, D-52425 Jülich, Germany
| | - Oliver Schillinger
- Institute of Complex Systems ICS-6: Structural Biochemistry, Forschungszentrum Jülich GmbH, D-52425 Jülich, Germany
| | - Timo Fettweiss
- Institut für Molekulare Enzymtechnologie, Heinrich-Heine Universität Düsseldorf, Forschungszentrum Jülich GmbH, D-52425 Jülich, Germany
| | - Christina Nutschel
- Institut für Molekulare Enzymtechnologie, Heinrich-Heine Universität Düsseldorf, Forschungszentrum Jülich GmbH, D-52425 Jülich, Germany
| | - Frank Krause
- Nanolytics, Gesellschaft für Kolloidanalytik GmbH, Am Mühlenberg 11, 14476 Potsdam, Germany
| | - Alexander Fulton
- Institut für Molekulare Enzymtechnologie, Heinrich-Heine Universität Düsseldorf, Forschungszentrum Jülich GmbH, D-52425 Jülich, Germany
| | - Birgit Strodel
- Institute of Complex Systems ICS-6: Structural Biochemistry, Forschungszentrum Jülich GmbH, D-52425 Jülich, Germany
| | - Andreas Stadler
- Jülich Centre for Neutron Science JCNS and Institute for Complex Systems ICS, Forschungszentrum Jülich GmbH, D-52425 Jülich, Germany
| | - Karl-Erich Jaeger
- Institut für Molekulare Enzymtechnologie, Heinrich-Heine Universität Düsseldorf, Forschungszentrum Jülich GmbH, D-52425 Jülich, Germany.,Institute of Bio- and Geosciences IBG-1: Biotechnology, Forschungszentrum Jülich GmbH, D-52425 Jülich, Germany
| | - Ulrich Krauss
- Institut für Molekulare Enzymtechnologie, Heinrich-Heine Universität Düsseldorf, Forschungszentrum Jülich GmbH, D-52425 Jülich, Germany
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20
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Abstract
Comparative protein structure modeling predicts the three-dimensional structure of a given protein sequence (target) based primarily on its alignment to one or more proteins of known structure (templates). The prediction process consists of fold assignment, target-template alignment, model building, and model evaluation. This unit describes how to calculate comparative models using the program MODELLER and how to use the ModBase database of such models, and discusses all four steps of comparative modeling, frequently observed errors, and some applications. Modeling lactate dehydrogenase from Trichomonas vaginalis (TvLDH) is described as an example. The download and installation of the MODELLER software is also described. © 2016 by John Wiley & Sons, Inc.
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Affiliation(s)
- Benjamin Webb
- University of California at San Francisco, San Francisco, California
| | - Andrej Sali
- University of California at San Francisco, San Francisco, California
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21
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Frank AT, Law SM, Ahlstrom LS, Brooks CL. Predicting protein backbone chemical shifts from Cα coordinates: extracting high resolution experimental observables from low resolution models. J Chem Theory Comput 2016; 11:325-31. [PMID: 25620895 PMCID: PMC4295808 DOI: 10.1021/ct5009125] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Indexed: 12/18/2022]
Abstract
![]()
Given
the demonstrated utility of coarse-grained modeling and simulations
approaches in studying protein structure and dynamics, developing
methods that allow experimental observables to be directly recovered from coarse-grained models is of great importance. In
this work, we develop one such method that enables protein backbone
chemical shifts (1HN, 1Hα, 13Cα, 13C, 13Cβ, and 15N) to be predicted from Cα coordinates. We show that our Cα-based
method, LARMORCα, predicts backbone chemical shifts
with comparable accuracy to some all-atom approaches. More importantly,
we demonstrate that LARMORCα predicted chemical shifts
are able to resolve native structure from decoy pools that contain
both native and non-native models, and so it is sensitive to protein
structure. As an application, we use LARMORCα to
characterize the transient state of the fast-folding protein gpW using
recently published NMR relaxation dispersion derived backbone chemical
shifts. The model we obtain is consistent with the previously proposed
model based on independent analysis of the chemical shift dispersion
pattern of the transient state. We anticipate that LARMORCα will find utility as a tool that enables important protein conformational
substates to be identified by “parsing” trajectories
and ensembles generated using coarse-grained modeling and simulations.
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Affiliation(s)
- Aaron T Frank
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
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22
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Webb B, Sali A. Comparative Protein Structure Modeling Using MODELLER. CURRENT PROTOCOLS IN BIOINFORMATICS 2016; 54:5.6.1-5.6.37. [PMID: 27322406 PMCID: PMC5031415 DOI: 10.1002/cpbi.3] [Citation(s) in RCA: 1880] [Impact Index Per Article: 235.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Comparative protein structure modeling predicts the three-dimensional structure of a given protein sequence (target) based primarily on its alignment to one or more proteins of known structure (templates). The prediction process consists of fold assignment, target-template alignment, model building, and model evaluation. This unit describes how to calculate comparative models using the program MODELLER and how to use the ModBase database of such models, and discusses all four steps of comparative modeling, frequently observed errors, and some applications. Modeling lactate dehydrogenase from Trichomonas vaginalis (TvLDH) is described as an example. The download and installation of the MODELLER software is also described. © 2016 by John Wiley & Sons, Inc.
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Affiliation(s)
- Benjamin Webb
- University of California at San Francisco, San Francisco, California
| | - Andrej Sali
- University of California at San Francisco, San Francisco, California
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23
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Deshmukh RA, Jagtap S, Mandal MK, Mandal SK. Purification, biochemical characterization and structural modelling of alkali-stable β-1,4-xylan xylanohydrolase from Aspergillus fumigatus R1 isolated from soil. BMC Biotechnol 2016; 16:11. [PMID: 26847222 PMCID: PMC4743132 DOI: 10.1186/s12896-016-0242-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Accepted: 01/20/2016] [Indexed: 11/30/2022] Open
Abstract
Background Aspergillus fumigatus R1 produced xylanase under submerged fermentation which degrades the complex hemicelluloses contained in agricultural substrates. Xylanases have gained considerable attention because of their tremendous applications in industries. The purpose of our study was to purify xylanase and study its biochemical properties. We have predicted the secondary structure of purified xylanase and evaluated its active site residues and substrate binding sites based on the global and local structural similarity. Results Various microorganisms were isolated from Puducherry soil and screened by Congo-red test. The best isolate was identified to be Aspergillus fumigatus R1. The production kinetics showed the highest xylanase production (208 IU/ml) by this organism in 96 h using 1 % rice bran as the only carbon source. The purification of extracellular xylanase was carried out by fractional ammonium sulphate precipitation (30–55 %), followed by extensive dialysis and Bio-Gel P-60 Gel-filtration chromatography. The enzyme was purified 58.10 folds with a specific activity of 38196.22 IU/mg. The biochemical characterization of the pure enzyme was carried out for its optimum pH and temperature (5.0 and 500C), pH and temperature stability, molecular mass (Mr) (24.5 kDa) and pI (6.29). The complete sequence of protein was obtained by mass spectrometry analysis. Apparent Km and Vmax values of the xylanase for birchwood xylan were 11.66 mg/ml and 87.6 μmol min−1 mg−1 respectively. Conclusion Purified xylanase was analyzed by mass-spectrometry which revealed 2 unique peptides. Xylanase under current study showed significant production using agricultural residues and a broad range of pH stability in the alkaline region. Xylanase produced by Aspergillus fumigatus R1 could serve as the enzyme of choice in industries.
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Affiliation(s)
- Rehan Ahmed Deshmukh
- Department of Microbiology, School Of Life-Sciences, Pondicherry University, R.V. Nagar, Kalapet, Puducherry, 605014, India.
| | - Sharmili Jagtap
- Department of Microbiology, School Of Life-Sciences, Pondicherry University, R.V. Nagar, Kalapet, Puducherry, 605014, India.
| | - Madan Kumar Mandal
- Department of Microbiology, School Of Life-Sciences, Pondicherry University, R.V. Nagar, Kalapet, Puducherry, 605014, India.
| | - Suraj Kumar Mandal
- Department of Microbiology, School Of Life-Sciences, Pondicherry University, R.V. Nagar, Kalapet, Puducherry, 605014, India.
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24
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Modeling of protein-peptide interactions using the CABS-dock web server for binding site search and flexible docking. Methods 2015; 93:72-83. [PMID: 26165956 DOI: 10.1016/j.ymeth.2015.07.004] [Citation(s) in RCA: 114] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Revised: 07/06/2015] [Accepted: 07/08/2015] [Indexed: 11/22/2022] Open
Abstract
Protein-peptide interactions play essential functional roles in living organisms and their structural characterization is a hot subject of current experimental and theoretical research. Computational modeling of the structure of protein-peptide interactions is usually divided into two stages: prediction of the binding site at a protein receptor surface, and then docking (and modeling) the peptide structure into the known binding site. This paper presents a comprehensive CABS-dock method for the simultaneous search of binding sites and flexible protein-peptide docking, available as a user's friendly web server. We present example CABS-dock results obtained in the default CABS-dock mode and using its advanced options that enable the user to increase the range of flexibility for chosen receptor fragments or to exclude user-selected binding modes from docking search. Furthermore, we demonstrate a strategy to improve CABS-dock performance by assessing the quality of models with classical molecular dynamics. Finally, we discuss the promising extensions and applications of the CABS-dock method and provide a tutorial appendix for the convenient analysis and visualization of CABS-dock results. The CABS-dock web server is freely available at http://biocomp.chem.uw.edu.pl/CABSdock/.
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25
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Chen T, Chan HS. Native contact density and nonnative hydrophobic effects in the folding of bacterial immunity proteins. PLoS Comput Biol 2015; 11:e1004260. [PMID: 26016652 PMCID: PMC4446218 DOI: 10.1371/journal.pcbi.1004260] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2015] [Accepted: 03/29/2015] [Indexed: 11/18/2022] Open
Abstract
The bacterial colicin-immunity proteins Im7 and Im9 fold by different mechanisms. Experimentally, at pH 7.0 and 10°C, Im7 folds in a three-state manner via an intermediate but Im9 folding is two-state-like. Accordingly, Im7 exhibits a chevron rollover, whereas the chevron arm for Im9 folding is linear. Here we address the biophysical basis of their different behaviors by using native-centric models with and without additional transferrable, sequence-dependent energies. The Im7 chevron rollover is not captured by either a pure native-centric model or a model augmented by nonnative hydrophobic interactions with a uniform strength irrespective of residue type. By contrast, a more realistic nonnative interaction scheme that accounts for the difference in hydrophobicity among residues leads simultaneously to a chevron rollover for Im7 and an essentially linear folding chevron arm for Im9. Hydrophobic residues identified by published experiments to be involved in nonnative interactions during Im7 folding are found to participate in the strongest nonnative contacts in this model. Thus our observations support the experimental perspective that the Im7 folding intermediate is largely underpinned by nonnative interactions involving large hydrophobics. Our simulation suggests further that nonnative effects in Im7 are facilitated by a lower local native contact density relative to that of Im9. In a one-dimensional diffusion picture of Im7 folding with a coordinate- and stability-dependent diffusion coefficient, a significant chevron rollover is consistent with a diffusion coefficient that depends strongly on native stability at the conformational position of the folding intermediate. In order to fold correctly, a globular protein must avoid being trapped in wrong, i.e., nonnative conformations. Thus a biophysical account of how attractive nonnative interactions are bypassed by some amino acid sequences but not others is key to deciphering protein structure and function. We examine two closely related bacterial immunity proteins, Im7 and Im9, that are experimentally known to fold very differently: Whereas Im9 folds directly, Im7 folds through a mispacked conformational intermediate. A simple model we developed accounts for their intriguingly different folding kinetics in terms of a balance between the density of native-promoting contacts and the hydrophobicity of local amino acid sequences. This emergent principle is extensible to other biomolecular recognition processes.
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Affiliation(s)
- Tao Chen
- Departments of Biochemistry, of Molecular Genetics, and of Physics, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Hue Sun Chan
- Departments of Biochemistry, of Molecular Genetics, and of Physics, University of Toronto, Toronto, Ontario M5S 1A8, Canada
- * E-mail:
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26
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Ahmed MH, Koparde VN, Safo MK, Neel Scarsdale J, Kellogg GE. 3d interaction homology: The structurally known rotamers of tyrosine derive from a surprisingly limited set of information-rich hydropathic interaction environments described by maps. Proteins 2015; 83:1118-36. [DOI: 10.1002/prot.24813] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2014] [Revised: 02/24/2015] [Accepted: 04/05/2015] [Indexed: 12/20/2022]
Affiliation(s)
- Mostafa H. Ahmed
- Institute for Structural Biology and Drug Discovery, Virginia Commonwealth University; Richmond VA 23298 USA
- Department of Medicinal Chemistry; Virginia Commonwealth University; Richmond VA 23298 USA
| | - Vishal N. Koparde
- Institute for Structural Biology and Drug Discovery, Virginia Commonwealth University; Richmond VA 23298 USA
- Department of Medicinal Chemistry; Virginia Commonwealth University; Richmond VA 23298 USA
| | - Martin K. Safo
- Institute for Structural Biology and Drug Discovery, Virginia Commonwealth University; Richmond VA 23298 USA
- Department of Medicinal Chemistry; Virginia Commonwealth University; Richmond VA 23298 USA
| | - J. Neel Scarsdale
- Institute for Structural Biology and Drug Discovery, Virginia Commonwealth University; Richmond VA 23298 USA
- Center for the Study of Biological Complexity; Virginia Commonwealth University; Richmond VA 23298 USA
| | - Glen E. Kellogg
- Institute for Structural Biology and Drug Discovery, Virginia Commonwealth University; Richmond VA 23298 USA
- Department of Medicinal Chemistry; Virginia Commonwealth University; Richmond VA 23298 USA
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27
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Moghadasi M, Mirzaei H, Mamonov A, Vakili P, Vajda S, Paschalidis IC, Kozakov D. The impact of side-chain packing on protein docking refinement. J Chem Inf Model 2015; 55:872-81. [PMID: 25714358 PMCID: PMC4734134 DOI: 10.1021/ci500380a] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
We study the impact of optimizing the side-chain positions in the interface region between two proteins during the process of binding. Mathematically, the problem is similar to side-chain prediction, which has been extensively explored in the process of protein structure prediction. The protein-protein docking application, however, has a number of characteristics that necessitate different algorithmic and implementation choices. In this work, we implement a distributed approximate algorithm that can be implemented on multiprocessor architectures and enables a trade-off between accuracy and running speed. We report computational results on benchmarks of enzyme-inhibitor and other types of complexes, establishing that the side-chain flexibility our algorithm introduces substantially improves the performance of docking protocols. Furthermore, we establish that the inclusion of unbound side-chain conformers in the side-chain positioning problem is critical in these performance improvements. The code is available to the community under open source license.
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Affiliation(s)
- Mohammad Moghadasi
- Division of Systems Engineering & Center for Information and Systems Engineering
| | - Hanieh Mirzaei
- Division of Systems Engineering & Center for Information and Systems Engineering
| | | | - Pirooz Vakili
- Division of Systems Engineering, and Department of Mechanical Engineering
| | | | - Ioannis Ch. Paschalidis
- Department of Electrical and Computer Engineering, Division of Systems Engineering, and Department of Biomedical Engineering
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28
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Li W, Cowley A, Uludag M, Gur T, McWilliam H, Squizzato S, Park YM, Buso N, Lopez R. The EMBL-EBI bioinformatics web and programmatic tools framework. Nucleic Acids Res 2015; 43:W580-4. [PMID: 25845596 PMCID: PMC4489272 DOI: 10.1093/nar/gkv279] [Citation(s) in RCA: 720] [Impact Index Per Article: 80.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 03/21/2015] [Indexed: 01/20/2023] Open
Abstract
Since 2009 the EMBL-EBI Job Dispatcher framework has provided free access to a range of mainstream sequence analysis applications. These include sequence similarity search services (https://www.ebi.ac.uk/Tools/sss/) such as BLAST, FASTA and PSI-Search, multiple sequence alignment tools (https://www.ebi.ac.uk/Tools/msa/) such as Clustal Omega, MAFFT and T-Coffee, and other sequence analysis tools (https://www.ebi.ac.uk/Tools/pfa/) such as InterProScan. Through these services users can search mainstream sequence databases such as ENA, UniProt and Ensembl Genomes, utilising a uniform web interface or systematically through Web Services interfaces (https://www.ebi.ac.uk/Tools/webservices/) using common programming languages, and obtain enriched results with novel visualisations. Integration with EBI Search (https://www.ebi.ac.uk/ebisearch/) and the dbfetch retrieval service (https://www.ebi.ac.uk/Tools/dbfetch/) further expands the usefulness of the framework. New tools and updates such as NCBI BLAST+, InterProScan 5 and PfamScan, new categories such as RNA analysis tools (https://www.ebi.ac.uk/Tools/rna/), new databases such as ENA non-coding, WormBase ParaSite, Pfam and Rfam, and new workflow methods, together with the retirement of depreciated services, ensure that the framework remains relevant to today's biological community.
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Affiliation(s)
- Weizhong Li
- European Bioinformatics Institute, EMBL Outstation, Wellcome Trust Genome Campus, Hinxton, CB10 1SD, Cambridge, UK
| | - Andrew Cowley
- European Bioinformatics Institute, EMBL Outstation, Wellcome Trust Genome Campus, Hinxton, CB10 1SD, Cambridge, UK
| | - Mahmut Uludag
- European Bioinformatics Institute, EMBL Outstation, Wellcome Trust Genome Campus, Hinxton, CB10 1SD, Cambridge, UK
| | - Tamer Gur
- European Bioinformatics Institute, EMBL Outstation, Wellcome Trust Genome Campus, Hinxton, CB10 1SD, Cambridge, UK
| | - Hamish McWilliam
- European Bioinformatics Institute, EMBL Outstation, Wellcome Trust Genome Campus, Hinxton, CB10 1SD, Cambridge, UK
| | - Silvano Squizzato
- European Bioinformatics Institute, EMBL Outstation, Wellcome Trust Genome Campus, Hinxton, CB10 1SD, Cambridge, UK
| | - Young Mi Park
- European Bioinformatics Institute, EMBL Outstation, Wellcome Trust Genome Campus, Hinxton, CB10 1SD, Cambridge, UK
| | - Nicola Buso
- European Bioinformatics Institute, EMBL Outstation, Wellcome Trust Genome Campus, Hinxton, CB10 1SD, Cambridge, UK
| | - Rodrigo Lopez
- European Bioinformatics Institute, EMBL Outstation, Wellcome Trust Genome Campus, Hinxton, CB10 1SD, Cambridge, UK
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29
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Peng X, Chenani A, Hu S, Zhou Y, Niemi AJ. A three dimensional visualisation approach to protein heavy-atom structure reconstruction. BMC STRUCTURAL BIOLOGY 2014; 14:27. [PMID: 25551190 PMCID: PMC4302604 DOI: 10.1186/s12900-014-0027-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Accepted: 12/16/2014] [Indexed: 11/10/2022]
Abstract
Background A commonly recurring problem in structural protein studies, is the determination of all heavy atom positions from the knowledge of the central α-carbon coordinates. Results We employ advances in virtual reality to address the problem. The outcome is a 3D visualisation based technique where all the heavy backbone and side chain atoms are treated on equal footing, in terms of the Cα coordinates. Each heavy atom is visualised on the surfaces of a different two-sphere, that is centered at another heavy backbone and side chain atoms. In particular, the rotamers are visible as clusters, that display a clear and strong dependence on the underlying backbone secondary structure. Conclusions We demonstrate that there is a clear interdependence between rotameric states and secondary structure. Our method easily detects those atoms in a crystallographic protein structure which are either outliers or have been likely misplaced, possibly due to radiation damage. Our approach forms a basis for the development of a new generation, visualization based side chain construction, validation and refinement tools. The heavy atom positions are identified in a manner which accounts for the secondary structure environment, leading to improved accuracy. Electronic supplementary material The online version of this article (doi:10.1186/s12900-014-0027-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Xubiao Peng
- Department of Physics and Astronomy, Uppsala University, Uppsala, Sweden.
| | - Alireza Chenani
- Department of Physics and Astronomy, Uppsala University, Uppsala, Sweden.
| | - Shuangwei Hu
- Department of Physics and Astronomy, Uppsala University, Uppsala, Sweden.
| | - Yifan Zhou
- Department of Biomedicine, Faculty of Medicine and Dentistry, University of Bergen, Jonas Lies Vei 91, NO-5009, Bergen, Norway.
| | - Antti J Niemi
- Department of Physics and Astronomy, Uppsala University, Uppsala, Sweden. .,Laboratoire de Mathematiques et Physique Theorique CNRS UMR 6083, Fédération Denis Poisson, Université de Tours, Parc de Grandmont, F37200, Tours, France.
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Abstract
Functional characterization of a protein sequence is one of the most frequent problems in biology. This task is usually facilitated by accurate three-dimensional (3-D) structure of the studied protein. In the absence of an experimentally determined structure, comparative or homology modeling can sometimes provide a useful 3-D model for a protein that is related to at least one known protein structure. Comparative modeling predicts the 3-D structure of a given protein sequence (target) based primarily on its alignment to one or more proteins of known structure (templates). The prediction process consists of fold assignment, target-template alignment, model building, and model evaluation. This unit describes how to calculate comparative models using the program MODELLER and discusses all four steps of comparative modeling, frequently observed errors, and some applications. Modeling lactate dehydrogenase from Trichomonas vaginalis (TvLDH) is described as an example. The download and installation of the MODELLER software is also described.
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Affiliation(s)
- Benjamin Webb
- University of California at San Francisco, San Francisco, California
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31
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Rysavy SJ, Beck DAC, Daggett V. Dynameomics: data-driven methods and models for utilizing large-scale protein structure repositories for improving fragment-based loop prediction. Protein Sci 2014; 23:1584-95. [PMID: 25142412 DOI: 10.1002/pro.2537] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2014] [Revised: 07/30/2014] [Accepted: 08/17/2014] [Indexed: 12/26/2022]
Abstract
Protein function is intimately linked to protein structure and dynamics yet experimentally determined structures frequently omit regions within a protein due to indeterminate data, which is often due protein dynamics. We propose that atomistic molecular dynamics simulations provide a diverse sampling of biologically relevant structures for these missing segments (and beyond) to improve structural modeling and structure prediction. Here we make use of the Dynameomics data warehouse, which contains simulations of representatives of essentially all known protein folds. We developed novel computational methods to efficiently identify, rank and retrieve small peptide structures, or fragments, from this database. We also created a novel data model to analyze and compare large repositories of structural data, such as contained within the Protein Data Bank and the Dynameomics data warehouse. Our evaluation compares these structural repositories for improving loop predictions and analyzes the utility of our methods and models. Using a standard set of loop structures, containing 510 loops, 30 for each loop length from 4 to 20 residues, we find that the inclusion of Dynameomics structures in fragment-based methods improves the quality of the loop predictions without being dependent on sequence homology. Depending on loop length, ∼ 25-75% of the best predictions came from the Dynameomics set, resulting in lower main chain root-mean-square deviations for all fragment lengths using the combined fragment library. We also provide specific cases where Dynameomics fragments provide better predictions for NMR loop structures than fragments from crystal structures. Online access to these fragment libraries is available at http://www.dynameomics.org/fragments.
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Affiliation(s)
- Steven J Rysavy
- Division of Biomedical and Health Informatics, University of Washington, Seattle, Washington
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32
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Law SM, Frank AT, Brooks CL. PCASSO: a fast and efficient Cα-based method for accurately assigning protein secondary structure elements. J Comput Chem 2014; 35:1757-61. [PMID: 24995959 DOI: 10.1002/jcc.23683] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2014] [Revised: 06/05/2014] [Accepted: 06/24/2014] [Indexed: 11/10/2022]
Abstract
Proteins are often characterized in terms of their primary, secondary, tertiary, and quaternary structure. Algorithms such as define secondary structure of proteins (DSSP) can automatically assign protein secondary structure based on the backbone hydrogen-bonding pattern. However, the assignment of secondary structure elements (SSEs) becomes a challenge when only the Cα coordinates are available. In this work, we present protein C-alpha secondary structure output (PCASSO), a fast and accurate program for assigning protein SSEs using only the Cα positions. PCASSO achieves ∼95% accuracy with respect to DSSP and takes ∼0.1 s using a single processor to analyze a 1000 residue system with multiple chains. Our approach was compared with current state-of-the-art Cα-based methods and was found to outperform all of them in both speed and accuracy. A practical application is also presented and discussed.
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Affiliation(s)
- Sean M Law
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan, 48109; Department of Biophysics, University of Michigan, Ann Arbor, Michigan, 48109, Fax: +1 (734) 647 1604
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33
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Ojha H, Panwar HS, Gorham RD, Morikis D, Sahu A. Viral regulators of complement activation: structure, function and evolution. Mol Immunol 2014; 61:89-99. [PMID: 24976595 DOI: 10.1016/j.molimm.2014.06.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Revised: 05/30/2014] [Accepted: 06/01/2014] [Indexed: 11/25/2022]
Abstract
The complement system surveillance in the host is effective in controlling viral propagation. Consequently, to subvert this effector mechanism, viruses have developed a series of adaptations. One among these is encoding mimics of host regulators of complement activation (RCA) which help viruses to avoid being labeled as 'foreign' and protect them from complement-mediated neutralization and complement-enhanced antiviral adaptive immunity. In this review, we provide an overview on the structure, function and evolution of viral RCA proteins.
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Affiliation(s)
- Hina Ojha
- National Centre for Cell Science, Pune University Campus, Ganeshkhind, Pune 411007, India
| | - Hemendra Singh Panwar
- National Centre for Cell Science, Pune University Campus, Ganeshkhind, Pune 411007, India
| | - Ronald D Gorham
- Department of Bioengineering, University of California, Riverside, CA 92521, USA
| | - Dimitrios Morikis
- Department of Bioengineering, University of California, Riverside, CA 92521, USA.
| | - Arvind Sahu
- National Centre for Cell Science, Pune University Campus, Ganeshkhind, Pune 411007, India.
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34
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In silico and in vivo studies of molecular structures and mechanisms of AtPCS1 protein involved in binding arsenite and/or cadmium in plant cells. J Mol Model 2014; 20:2104. [DOI: 10.1007/s00894-014-2104-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2013] [Accepted: 12/04/2013] [Indexed: 12/20/2022]
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35
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Abstract
Structural proteomics aims to understand the structural basis of protein interactions and functions. A prerequisite for this is the availability of 3D protein structures that mediate the biochemical interactions. The explosion in the number of available gene sequences set the stage for the next step in genome-scale projects -- to obtain 3D structures for each protein. To achieve this ambitious goal, the slow and costly structure determination experiments are supplemented with theoretical approaches. The current state and recent advances in structure modeling approaches are reviewed here, with special emphasis on comparative protein structure modeling techniques.
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Affiliation(s)
- András Fiser
- Department of Biochemistry, Seaver Foundation Center for Bioinformatics, Albert Einstein College of Medicine, 1300 Morris Park Ave., Bronx, NY 10461, USA.
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36
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Tsurumura T, Qiu H, Yoshida T, Tsumori Y, Hatakeyama D, Kuzuhara T, Tsuge H. Conformational polymorphism of m7GTP in crystal structure of the PB2 middle domain from human influenza A virus. PLoS One 2013; 8:e82020. [PMID: 24312396 PMCID: PMC3843726 DOI: 10.1371/journal.pone.0082020] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Accepted: 10/28/2013] [Indexed: 01/07/2023] Open
Abstract
Influenza pandemics with human-to-human transmission of the virus are of great public concern. It is now recognized that a number of factors are necessary for human transmission and virulence, including several key mutations within the PB2 subunit of RNA-dependent RNA polymerase. The structure of the middle domain in PB2 has been revealed with or without m(7)GTP, thus the middle domain is considered to be novel target for structure-based drug design. Here we report the crystal structure of the middle domain of H1N1 PB2 with or without m(7)GTP at 1.9 Å and 2.0 Å resolution, respectively, which has two mutations (P453H, I471T) to increase electrostatic potential and solubility. Here we report the m(7)GTP has unique conformation differ from the reported structure. 7-methyl-guanine is fixed in the pocket, but particularly significant change is seen in ribose and triphosphate region: the buried 7-methyl-guanine indeed binds in the pocket forming by H357, F404, E361 and K376 but the triphosphate continues directly to the outer domain. The presented conformation of m(7)GTP may be a clue for the anti-influenza drug-design.
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Affiliation(s)
- Toshiharu Tsurumura
- Faculty of Life Sciences, Kyoto Sangyo University, Kamigamo-Motoyama, Kyoto, Japan
| | - Hao Qiu
- Faculty of Life Sciences, Kyoto Sangyo University, Kamigamo-Motoyama, Kyoto, Japan
| | - Toru Yoshida
- Faculty of Life Sciences, Kyoto Sangyo University, Kamigamo-Motoyama, Kyoto, Japan
| | - Yayoi Tsumori
- Faculty of Life Sciences, Kyoto Sangyo University, Kamigamo-Motoyama, Kyoto, Japan
| | - Dai Hatakeyama
- Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Tokushima, Japan
| | - Takashi Kuzuhara
- Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Tokushima, Japan
| | - Hideaki Tsuge
- Faculty of Life Sciences, Kyoto Sangyo University, Kamigamo-Motoyama, Kyoto, Japan
- * E-mail:
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37
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Castellana NE, Lushnikov A, Rotkiewicz P, Sefcovic N, Pevzner PA, Godzik A, Vyatkina K. MORPH-PRO: a novel algorithm and web server for protein morphing. Algorithms Mol Biol 2013; 8:19. [PMID: 23844614 PMCID: PMC3738870 DOI: 10.1186/1748-7188-8-19] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2013] [Accepted: 06/29/2013] [Indexed: 12/04/2022] Open
Abstract
Background Proteins are known to be dynamic in nature, changing from one conformation to another while performing vital cellular tasks. It is important to understand these movements in order to better understand protein function. At the same time, experimental techniques provide us with only single snapshots of the whole ensemble of available conformations. Computational protein morphing provides a visualization of a protein structure transitioning from one conformation to another by producing a series of intermediate conformations. Results We present a novel, efficient morphing algorithm, Morph-Pro based on linear interpolation. We also show that apart from visualization, morphing can be used to provide plausible intermediate structures. We test this by using the intermediate structures of a c-Jun N-terminal kinase (JNK1) conformational change in a virtual docking experiment. The structures are shown to dock with higher score to known JNK1-binding ligands than structures solved using X-Ray crystallography. This experiment demonstrates the potential applications of the intermediate structures in modeling or virtual screening efforts. Conclusions Visualization of protein conformational changes is important for characterization of protein function. Furthermore, the intermediate structures produced by our algorithm are good approximations to true structures. We believe there is great potential for these computationally predicted structures in protein-ligand docking experiments and virtual screening. The Morph-Pro web server can be accessed at http://morph-pro.bioinf.spbau.ru.
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38
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Mishra S, Saxena A, Sangwan RS. Fundamentals of Homology Modeling Steps and Comparison among Important Bioinformatics Tools: An Overview. ACTA ACUST UNITED AC 2013. [DOI: 10.17311/sciintl.2013.237.252] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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39
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MacDonald JT, Kelley LA, Freemont PS. Validating a Coarse-Grained Potential Energy Function through Protein Loop Modelling. PLoS One 2013; 8:e65770. [PMID: 23824634 PMCID: PMC3688807 DOI: 10.1371/journal.pone.0065770] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2013] [Accepted: 04/26/2013] [Indexed: 12/02/2022] Open
Abstract
Coarse-grained (CG) methods for sampling protein conformational space have the potential to increase computational efficiency by reducing the degrees of freedom. The gain in computational efficiency of CG methods often comes at the expense of non-protein like local conformational features. This could cause problems when transitioning to full atom models in a hierarchical framework. Here, a CG potential energy function was validated by applying it to the problem of loop prediction. A novel method to sample the conformational space of backbone atoms was benchmarked using a standard test set consisting of 351 distinct loops. This method used a sequence-independent CG potential energy function representing the protein using -carbon positions only and sampling conformations with a Monte Carlo simulated annealing based protocol. Backbone atoms were added using a method previously described and then gradient minimised in the Rosetta force field. Despite the CG potential energy function being sequence-independent, the method performed similarly to methods that explicitly use either fragments of known protein backbones with similar sequences or residue-specific /-maps to restrict the search space. The method was also able to predict with sub-Angstrom accuracy two out of seven loops from recently solved crystal structures of proteins with low sequence and structure similarity to previously deposited structures in the PDB. The ability to sample realistic loop conformations directly from a potential energy function enables the incorporation of additional geometric restraints and the use of more advanced sampling methods in a way that is not possible to do easily with fragment replacement methods and also enable multi-scale simulations for protein design and protein structure prediction. These restraints could be derived from experimental data or could be design restraints in the case of computational protein design. C++ source code is available for download from http://www.sbg.bio.ic.ac.uk/phyre2/PD2/.
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Affiliation(s)
- James T. MacDonald
- Division of Molecular Biosciences, Imperial College London, London, United Kingdom
- * E-mail:
| | - Lawrence A. Kelley
- Division of Molecular Biosciences, Imperial College London, London, United Kingdom
| | - Paul S. Freemont
- Division of Molecular Biosciences, Imperial College London, London, United Kingdom
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40
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Smith DW, Han MR, Park JS, Kim KR, Yeom T, Lee JY, Kim DJ, Bingman CA, Kim HJ, Jo K, Han BW, Phillips GN. Crystal structure of the protein from Arabidopsis thaliana gene At5g06450, a putative DnaQ-like exonuclease domain-containing protein with homohexameric assembly. Proteins 2013; 81:1669-1675. [PMID: 23616405 DOI: 10.1002/prot.24315] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2013] [Revised: 03/09/2013] [Accepted: 03/17/2013] [Indexed: 01/17/2023]
Abstract
Arabidopsis thaliana gene At5g06450 encodes a putative DnaQ-like 3'-5' exonuclease domain-containing protein (AtDECP). The DnaQ-like 3'-5' exonuclease domain is often found as a proofreading domain of DNA polymerases. The overall structure of AtDECP adopts an RNase H fold that consists of a mixed β-sheet flanked by α-helices. Interestingly, AtDECP forms a homohexameric assembly with a central six fold symmetry, generating a central cavity. The ring-shaped structure and comparison with WRN-exo, the best structural homologue of AtDECP, suggest a possible mechanism for implementing its exonuclease activity using positively charged patch on the N-terminal side of the homohexameric assembly. The homohexameric structure of AtDECP provides unique information about the interaction between the DnaQ-like 3'-5' exonuclease and its substrate nucleic acids.
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Affiliation(s)
- David W Smith
- Center for Eukaryotic Structural Genomics, Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Mi Ra Han
- Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul 151-742, Korea
| | - Joon Sung Park
- Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul 151-742, Korea
| | - Kyung Rok Kim
- Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul 151-742, Korea
| | - Taeho Yeom
- Department of Chemistry, Sogang University, Seoul 121-742, Korea
| | - Ji Yeon Lee
- Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul 151-742, Korea
| | - Do Jin Kim
- Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul 151-742, Korea
| | - Craig A Bingman
- Center for Eukaryotic Structural Genomics, Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Hyun-Jung Kim
- College of Pharmacy, Chung-Ang University, Seoul 156-756, Korea
| | - Kyubong Jo
- Department of Chemistry, Sogang University, Seoul 121-742, Korea
| | - Byung Woo Han
- Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul 151-742, Korea
| | - George N Phillips
- Center for Eukaryotic Structural Genomics, Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.,Department of Biochemistry and Cell Biology, Rice University, Houston, TX 77251, USA
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41
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Moore BL, Kelley LA, Barber J, Murray JW, MacDonald JT. High-quality protein backbone reconstruction from alpha carbons using Gaussian mixture models. J Comput Chem 2013; 34:1881-9. [PMID: 23703289 DOI: 10.1002/jcc.23330] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2013] [Revised: 04/01/2013] [Accepted: 04/21/2013] [Indexed: 11/08/2022]
Abstract
Coarse-grained protein structure models offer increased efficiency in structural modeling, but these must be coupled with fast and accurate methods to revert to a full-atom structure. Here, we present a novel algorithm to reconstruct mainchain models from C traces. This has been parameterized by fitting Gaussian mixture models (GMMs) to short backbone fragments centered on idealized peptide bonds. The method we have developed is statistically significantly more accurate than several competing methods, both in terms of RMSD values and dihedral angle differences. The method produced Ramachandran dihedral angle distributions that are closer to that observed in real proteins and better Phaser molecular replacement log-likelihood gains. Amino acid residue sidechain reconstruction accuracy using SCWRL4 was found to be statistically significantly correlated to backbone reconstruction accuracy. Finally, the PD2 method was found to produce significantly lower energy full-atom models using Rosetta which has implications for multiscale protein modeling using coarse-grained models. A webserver and C++ source code is freely available for noncommercial use from: http://www.sbg.bio.ic.ac.uk/phyre2/PD2_ca2main/.
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Affiliation(s)
- Benjamin L Moore
- Division of Molecular Biosciences, Imperial College, South Kensington Campus, London, United Kingdom
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42
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Vyas VK, Ukawala RD, Ghate M, Chintha C. Homology modeling a fast tool for drug discovery: current perspectives. Indian J Pharm Sci 2012. [PMID: 23204616 PMCID: PMC3507339 DOI: 10.4103/0250-474x.102537] [Citation(s) in RCA: 139] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Major goal of structural biology involve formation of protein-ligand complexes; in which the protein molecules act energetically in the course of binding. Therefore, perceptive of protein-ligand interaction will be very important for structure based drug design. Lack of knowledge of 3D structures has hindered efforts to understand the binding specificities of ligands with protein. With increasing in modeling software and the growing number of known protein structures, homology modeling is rapidly becoming the method of choice for obtaining 3D coordinates of proteins. Homology modeling is a representation of the similarity of environmental residues at topologically corresponding positions in the reference proteins. In the absence of experimental data, model building on the basis of a known 3D structure of a homologous protein is at present the only reliable method to obtain the structural information. Knowledge of the 3D structures of proteins provides invaluable insights into the molecular basis of their functions. The recent advances in homology modeling, particularly in detecting and aligning sequences with template structures, distant homologues, modeling of loops and side chains as well as detecting errors in a model contributed to consistent prediction of protein structure, which was not possible even several years ago. This review focused on the features and a role of homology modeling in predicting protein structure and described current developments in this field with victorious applications at the different stages of the drug design and discovery.
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Affiliation(s)
- V K Vyas
- Department of Pharmaceutical Chemistry, Institute of Pharmacy, Nirma University, Ahmedabad-382 481, India
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43
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Derache C, Epinette C, Roussel A, Gabant G, Cadene M, Korkmaz B, Gauthier F, Kellenberger C. Crystal structure of greglin, a novel non-classical Kazal inhibitor, in complex with subtilisin. FEBS J 2012; 279:4466-78. [DOI: 10.1111/febs.12033] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2012] [Revised: 10/05/2012] [Accepted: 10/09/2012] [Indexed: 01/23/2023]
Affiliation(s)
- Chrystelle Derache
- Centre de Biophysique Moléculaire; UPR 4301 CNRS conventionnée avec l'Université d'Orléans; Orléans Cedex 2; France
| | - Christophe Epinette
- Pathologies Respiratoires; Protéolyse et Aérosolthérapie; INSERM U1100 Faculté de Médecine; Université François Rabelais; Tours; France
| | - Alain Roussel
- Architecture et Fonction des Macromolécules Biologiques; CNRS UMR7257 and Aix-Marseille Université; Marseille Cedex; France
| | - Guillaume Gabant
- Centre de Biophysique Moléculaire; UPR 4301 CNRS conventionnée avec l'Université d'Orléans; Orléans Cedex 2; France
| | - Martine Cadene
- Centre de Biophysique Moléculaire; UPR 4301 CNRS conventionnée avec l'Université d'Orléans; Orléans Cedex 2; France
| | - Brice Korkmaz
- Pathologies Respiratoires; Protéolyse et Aérosolthérapie; INSERM U1100 Faculté de Médecine; Université François Rabelais; Tours; France
| | - Francis Gauthier
- Pathologies Respiratoires; Protéolyse et Aérosolthérapie; INSERM U1100 Faculté de Médecine; Université François Rabelais; Tours; France
| | - Christine Kellenberger
- Architecture et Fonction des Macromolécules Biologiques; CNRS UMR7257 and Aix-Marseille Université; Marseille Cedex; France
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44
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Maadooliat M, Gao X, Huang JZ. Assessing protein conformational sampling methods based on bivariate lag-distributions of backbone angles. Brief Bioinform 2012; 14:724-36. [PMID: 22926831 DOI: 10.1093/bib/bbs052] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Despite considerable progress in the past decades, protein structure prediction remains one of the major unsolved problems in computational biology. Angular-sampling-based methods have been extensively studied recently due to their ability to capture the continuous conformational space of protein structures. The literature has focused on using a variety of parametric models of the sequential dependencies between angle pairs along the protein chains. In this article, we present a thorough review of angular-sampling-based methods by assessing three main questions: What is the best distribution type to model the protein angles? What is a reasonable number of components in a mixture model that should be considered to accurately parameterize the joint distribution of the angles? and What is the order of the local sequence-structure dependency that should be considered by a prediction method? We assess the model fits for different methods using bivariate lag-distributions of the dihedral/planar angles. Moreover, the main information across the lags can be extracted using a technique called Lag singular value decomposition (LagSVD), which considers the joint distribution of the dihedral/planar angles over different lags using a nonparametric approach and monitors the behavior of the lag-distribution of the angles using singular value decomposition. As a result, we developed graphical tools and numerical measurements to compare and evaluate the performance of different model fits. Furthermore, we developed a web-tool (http://www.stat.tamu.edu/∼madoliat/LagSVD) that can be used to produce informative animations.
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Affiliation(s)
- Mehdi Maadooliat
- Mathematical and Computer Sciences and Engineering Division, 4700 King Abdullah University of Science and Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia, . Jianhua Z. Huang, Department of Statistics, 447 Blocker Building, Texas A&M University, 3143 TAMU, College Station, TX 77843-3143 (USA), E-mail:
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45
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Nahar N, Rahman A, Moś M, Warzecha T, Algerin M, Ghosh S, Johnson-Brousseau S, Mandal A. In silico and in vivo studies of an Arabidopsis thaliana gene, ACR2, putatively involved in arsenic accumulation in plants. J Mol Model 2012; 18:4249-62. [PMID: 22562211 DOI: 10.1007/s00894-012-1419-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2012] [Accepted: 03/26/2012] [Indexed: 12/27/2022]
Abstract
Previously, our in silico analyses identified four candidate genes that might be involved in uptake and/or accumulation of arsenics in plants: arsenate reductase 2 (ACR2), phytochelatin synthase 1 (PCS1) and two multi-drug resistant proteins (MRP1 and MRP2) [Lund et al. (2010) J Biol Syst 18:223-224]. We also postulated that one of these four genes, ACR2, seems to play a central role in this process. To investigate further, we have constructed a 3D structure of the Arabidopsis thaliana ACR2 protein using the iterative implementation of the threading assembly refinement (I-TASSER) server. These analyses revealed that, for catalytic metabolism of arsenate, the arsenate binding-loop (AB-loop) and residues Phe-53, Phe-54, Cys-134, Cys-136, Cys-141, Cys-145, and Lys-135 are essential for reducing arsenate to arsenic intermediates (arsenylated enzyme-substrate intermediates) and arsenite in plants. Thus, functional predictions suggest that the ACR2 protein is involved in the conversion of arsenate to arsenite in plant cells. To validate the in silico results, we exposed a transfer-DNA (T-DNA)-tagged mutant of A. thaliana (mutation in the ACR2 gene) to various amounts of arsenic. Reverse transcriptase PCR revealed that the mutant exhibits significantly reduced expression of the ACR2 gene. Spectrophotometric analyses revealed that the amount of accumulated arsenic compounds in this mutant was approximately six times higher than that observed in control plants. The results obtained from in silico analyses are in complete agreement with those obtained in laboratory experiments.
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Affiliation(s)
- Noor Nahar
- School of Life Sciences, University of Skövde, PO Box 408, 541 28, Skövde, Sweden
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46
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Jeschke G. Characterization of Protein Conformational Changes with Sparse Spin-Label Distance Constraints. J Chem Theory Comput 2012; 8:3854-63. [PMID: 26593026 DOI: 10.1021/ct300113z] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The combination of site-directed spin labeling with pulse EPR distance measurements can provide a moderate number of distance constraints on the nanometer length scale for proteins in different states. By adapting an existing algorithm (Zheng, W.; Brooks, B. R. Biophys. J. 2006, 90, 4327) to the problem, we address the question to what extent conformational change can be characterized when the protein structure is known for one of the states, whereas only a sparse set of distance constraints between spin labels is available for the other state. We find that the type and general direction of the conformational change can be recognized, while the amplitude may be uncertain.
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Affiliation(s)
- G Jeschke
- Lab. Phys. Chem., ETH Zürich, Wolfgang-Pauli-Strasse 10, CH-8093 Zürich, Switzerland
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Ravella D, Kumar MU, Sherlin D, Shankar M, Vaishnavi MK, Sekar K. SMS 2.0: an updated database to study the structural plasticity of short peptide fragments in non-redundant proteins. GENOMICS, PROTEOMICS & BIOINFORMATICS 2012; 10:44-50. [PMID: 22449400 PMCID: PMC5054494 DOI: 10.1016/s1672-0229(11)60032-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/11/2011] [Accepted: 12/19/2011] [Indexed: 11/21/2022]
Abstract
The function of a protein molecule is greatly influenced by its three-dimensional (3D) structure and therefore structure prediction will help identify its biological function. We have updated Sequence, Motif and Structure (SMS), the database of structurally rigid peptide fragments, by combining amino acid sequences and the corresponding 3D atomic coordinates of non-redundant (25%) and redundant (90%) protein chains available in the Protein Data Bank (PDB). SMS 2.0 provides information pertaining to the peptide fragments of length 5-14 residues. The entire dataset is divided into three categories, namely, same sequence motifs having similar, intermediate or dissimilar 3D structures. Further, options are provided to facilitate structural superposition using the program structural alignment of multiple proteins (STAMP) and the popular JAVA plug-in (Jmol) is deployed for visualization. In addition, functionalities are provided to search for the occurrences of the sequence motifs in other structural and sequence databases like PDB, Genome Database (GDB), Protein Information Resource (PIR) and Swiss-Prot. The updated database along with the search engine is available over the World Wide Web through the following URL http://cluster.physics.iisc.ernet.in/sms/.
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Affiliation(s)
| | | | | | | | | | - Kanagaraj Sekar
- Bioinformatics Centre (Centre of Excellence in Structural Biology and Bio-computing), Supercomputer Education and Research Centre, Indian Institute of Science, Bangalore 560012, India
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48
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Li SC, Bu D, Li M. Residues with similar hexagon neighborhoods share similar side-chain conformations. IEEE/ACM TRANSACTIONS ON COMPUTATIONAL BIOLOGY AND BIOINFORMATICS 2012; 9:240-248. [PMID: 21519113 DOI: 10.1109/tcbb.2011.74] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We present in this study a new approach to code protein side-chain conformations into hexagon substructures. Classical side-chain packing methods consist of two steps: first, side-chain conformations, known as rotamers, are extracted from known protein structures as candidates for each residue; second, a searching method along with an energy function is used to resolve conflicts among residues and to optimize the combinations of side chain conformations for all residues. These methods benefit from the fact that the number of possible side-chain conformations is limited, and the rotamer candidates are readily extracted; however, these methods also suffer from the inaccuracy of energy functions. Inspired by threading and Ab Initio approaches to protein structure prediction, we propose to use hexagon substructures to implicitly capture subtle issues of energy functions. Our initial results indicate that even without guidance from an energy function, hexagon structures alone can capture side-chain conformations at an accuracy of 83.8 percent, higher than 82.6 percent by the state-of-art side-chain packing methods.
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49
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Gu M, Dong X, Shi L, Shi L, Lin K, Huang X, Chu J. Differences in mtDNA whole sequence between Tibetan and Han populations suggesting adaptive selection to high altitude. Gene 2011; 496:37-44. [PMID: 22233893 DOI: 10.1016/j.gene.2011.12.016] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2011] [Revised: 12/02/2011] [Accepted: 12/06/2011] [Indexed: 10/14/2022]
Abstract
We performed a mitochondrial whole-genome comparison study in 40 Tibetan and 50 Han Chinese. All subjects could be classified into 13 haplogroups pertained to the Macrohaplogroup M and N that pitched different quadrants by principal component analysis. We observed a difference in the M9 haplogroup and identified 18 significant variants by comparing whole sequences between Tibetan and Han populations. Variants in ND2, COX2, tRNA alanine and 12S rRNA were predicted to confer increased protein stability in Tibetans. We compared the base substitutions of nonsynonymous (NS) versus synonymous (S) of 13 protein-encoding genes and found the NS/S values of the ATP6, ATP8, and Cyt b genes were larger (>1) in Tibetans than that in Han population. Our findings provide clues for the existence of adaptive selection for the ATP6, ATP8, Cyt b, ND2, COX2, tRNA alanine and 12S rRNA genes in Tibetans which likely contributed to adaptation to their specific geographic environment, such as high altitude.
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Affiliation(s)
- Mingliang Gu
- Department of Medical Genetics, Institute of Medical Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Kunming, China
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50
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Dotu I, Cebrián M, Van Hentenryck P, Clote P. On lattice protein structure prediction revisited. IEEE/ACM TRANSACTIONS ON COMPUTATIONAL BIOLOGY AND BIOINFORMATICS 2011; 8:1620-1632. [PMID: 21358007 DOI: 10.1109/tcbb.2011.41] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Protein structure prediction is regarded as a highly challenging problem both for the biology and for the computational communities. In recent years, many approaches have been developed, moving to increasingly complex lattice models and off-lattice models. This paper presents a Large Neighborhood Search (LNS) to find the native state for the Hydrophobic-Polar (HP) model on the Face-Centered Cubic (FCC) lattice or, in other words, a self-avoiding walk on the FCC lattice having a maximum number of H-H contacts. The algorithm starts with a tabu-search algorithm, whose solution is then improved by a combination of constraint programming and LNS. The flexible framework of this hybrid algorithm allows an adaptation to the Miyazawa-Jernigan contact potential, in place of the HP model, thus suggesting its potential for tertiary structure prediction. Benchmarking statistics are given for our method against the hydrophobic core threading program HPstruct, an exact method which can be viewed as complementary to our method.
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Affiliation(s)
- Ivan Dotu
- Biology Department, Boston College, Higgins 355, 140 Commonwealth Avenue, Chestnut Hill, MA 02467, USA.
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