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Belviso BD, Shen Y, Carrozzini B, Morishita M, di Luccio E, Caliandro R. Structural insights into the C-terminus of the histone-lysine N-methyltransferase NSD3 by small-angle X-ray scattering. Front Mol Biosci 2024; 11:1191246. [PMID: 38516186 PMCID: PMC10955146 DOI: 10.3389/fmolb.2024.1191246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Accepted: 02/19/2024] [Indexed: 03/23/2024] Open
Abstract
NSD3 is a member of six H3K36-specific histone lysine methyltransferases in metazoans. Its overexpression or mutation is implicated in developmental defects and oncogenesis. Aside from the well-characterized catalytic SET domain, NSD3 has multiple clinically relevant potential chromatin-binding motifs, such as the proline-tryptophan-tryptophan-proline (PWWP), the plant homeodomain (PHD), and the adjacent Cys-His-rich domain located at the C-terminus. The crystal structure of the individual domains is available, and this structural knowledge has allowed the designing of potential inhibitors, but the intrinsic flexibility of larger constructs has hindered the characterization of mutual domain conformations. Here, we report the first structural characterization of the NSD3 C-terminal region comprising the PWWP2, SET, and PHD4 domains, which has been achieved at a low resolution in solution by small-angle X-ray scattering (SAXS) data on two multiple-domain NSD3 constructs complemented with size-exclusion chromatography and advanced computational modeling. Structural models predicted by machine learning have been validated in direct space, by comparison with the SAXS-derived molecular envelope, and in reciprocal space, by reproducing the experimental SAXS profile. Selected models have been refined by SAXS-restrained molecular dynamics. This study shows how SAXS data can be used with advanced computational modeling techniques to achieve a detailed structural characterization and sheds light on how NSD3 domains are interconnected in the C-terminus.
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Affiliation(s)
| | - Yunpeng Shen
- Department of Biotechnology, School of Biological Engineering, Henan University of Technology, Zhengzhou, Henan, China
| | | | - Masayo Morishita
- Department of Genetic Engineering, School of Life Sciences, College of Natural Sciences, Kyungpook National University, Daegu, Republic of Korea
| | - Eric di Luccio
- Department of Genetic Engineering, School of Life Sciences, College of Natural Sciences, Kyungpook National University, Daegu, Republic of Korea
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Karthika A, Hemavathy N, Amala M, Rajamanikandan S, Veerapandian M, Prabhu D, Vetrivel U, Jung Chen C, Jeyaraj Pandian C, Jeyakanthan J. Structural and functional characterization of 6-phosphogluconate dehydrogenase in Plasmodium falciparum (3D7) and identification of its potent inhibitors. J Biomol Struct Dyn 2024; 42:2058-2074. [PMID: 37599457 DOI: 10.1080/07391102.2023.2248271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Accepted: 04/09/2023] [Indexed: 08/22/2023]
Abstract
The malarial parasite Plasmodium falciparum predominantly causes severe malaria and deaths worldwide. Moreover, resistance developed by P. falciparum to frontline drugs in recent years has markedly increased malaria-related deaths in South Asian Countries. Ribulose 5-phosphate and NADPH synthesized by Pentose Phosphate Pathway (PPP) act as a direct precursor for nucleotide synthesis and P. falciparum survival during oxidative challenges in the intra-erythrocytic growth phase . In the present study, we have elucidated the structure and functional characteristics of 6-phosphogluconate dehydrogenase (6PGD) in P. falciparum and have identified potent hits against 6PGD by pharmacophore-based virtual screening with ZINC and ChemBridge databases. Molecular docking and Molecular dynamics simulation, binding free energies (MMGBSA & MMPBSA), and Density Functional Theory (DFT) calculations were integratively employed to validate and prioritize the most potential hits. The 6PGD structure was found to have an open and closed conformation during MD simulation. The apo form of 6PGD was found to be in closed conformation, while a open conformation attributed to facilitating binding of cofactor. It was also inferred from the conformational analysis that the small domain of 6PGD has a high influence in altering the conformation that may aid in open/closed conformation of 6PGD. The top three hits identified using pharmacophore hypotheses were ChemBridge_11084819, ChemBridge_80178394, and ChemBridge_17912340. Though all three hits scored a high glide score, MMGBSA, and favorable ADMET properties, ChemBridge_11084819 and ChemBrdige_17912340 showed higher stability and binding free energy. Moreover, these hits also featured stable H-bond interactions with the active loop of 6PGD with binding free energy comparable to substrate-bound complex. Therefore, the ChemBridge_11084819 and ChemBridge_17912340 moieties demonstrate to have high therapeutic potential against 6PGD in P. falciparum.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Alagesan Karthika
- Structural Biology and Bio-Computing Lab, Department of Bioinformatics, Science Block, Alagappa University, Karaikudi, Tamil Nadu, India
| | - Nagarajan Hemavathy
- Structural Biology and Bio-Computing Lab, Department of Bioinformatics, Science Block, Alagappa University, Karaikudi, Tamil Nadu, India
- Centre for Bioinformatics, Vision Research Foundation, Chennai, Tamil Nadu, India
| | - Mathimaran Amala
- Structural Biology and Bio-Computing Lab, Department of Bioinformatics, Science Block, Alagappa University, Karaikudi, Tamil Nadu, India
| | - Sundaraj Rajamanikandan
- Centre for Drug Discovery, Karpagam Academy of Higher Education, Coimbatore, Tamil Nadu, India
| | - Malaisamy Veerapandian
- Structural Biology and Bio-Computing Lab, Department of Bioinformatics, Science Block, Alagappa University, Karaikudi, Tamil Nadu, India
| | - Dhamodharan Prabhu
- Centre for Drug Discovery, Karpagam Academy of Higher Education, Coimbatore, Tamil Nadu, India
| | - Umashankar Vetrivel
- ICMR-National Institute of Traditional Medicine, Nehru Nagar, Belagavi, Karnataka, India
- ICMR-National Institute for Research in Tuberculosis, Chennai, Tamil Nadu, India
| | - Chun Jung Chen
- Life Science Group, Scientific Research Division, National Synchrotron Radiation Research Center, Hsinchu, Taiwan
| | - Chitra Jeyaraj Pandian
- Department of Biotechnology, Dr. Umayal Ramanathan College for Women, Karaikudi, Tamil Nadu, India
| | - Jeyaraman Jeyakanthan
- Structural Biology and Bio-Computing Lab, Department of Bioinformatics, Science Block, Alagappa University, Karaikudi, Tamil Nadu, India
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Deciphering the conformational transitions of LIMK2 active and inactive states to ponder specific druggable states through microsecond scale molecular dynamics simulation. J Comput Aided Mol Des 2022; 36:459-482. [PMID: 35652973 DOI: 10.1007/s10822-022-00459-0] [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: 02/26/2022] [Accepted: 05/16/2022] [Indexed: 10/18/2022]
Abstract
LIMK2 inhibitors are one of the potential therapeutic modalities for treating various diseases. In the current scenario, there is a paucity of effective LIMK inhibitors that are highly specific with minimal off-target effects. To date, the conformational transitions of LIMK2 from DFGinαCin (CIDI) (active) to DFGoutαCout (CODO) (inactive) states are yet to be probed and are essential for capturing the unique, druggable conformations. Therefore, this study was intended to capture the diverse conformational states of LIMK2 for accelerating the rational identification of conformation specific inhibitors through high-end structural bioinformatics protocols. Hence, in this study, molecular modelling followed by an extensive microsecond timescale of molecular dynamics simulation was performed encompassing perturbation response scanning, metapath, and community analysis towards the conformational sampling of LIMK2. Overall this study precisely identifies the conformational ensemble of LIMK2 the intermediate inactive states namely, CIDO, CinterDinter, CIDinter, CinterDI, CinterDO, CODI, CODinter apart from CIDI and CODO. This also facilitated observing that β8 preceding XDFG, αC (F373, L374), and αD (L413) as the major effectors that may facilitate the regulation of varying conformational transitions among the states. Additionally, the conserved β sheets and the loops namely, C.l, b.l, and G/P.loop were observed to be involved in the metapath for allosteric communication among the intermediates with CIDI and CODO state. Moreover, only the CODO state was observed to have closed type A.l, while the CIDI and other intermediate states except for CIDO were observed to have open-DFG out type A.l, thereby enabling the binding of substrate. Apart from these, the druggable site analysis inferred that the CIDI and CODO states harbor prominent druggable sites spanning the conserved N-lobe, while the intermediates were observed to have unraveled allosteric druggable sites distal from the ATP binding site, majorly spanning the C-lobe of LIMK2. Thus, this study provides potential insights into the intermediate conformational druggable states of LIMK2 and also the druggable conformations, especially the inactive states of LIMK2, as a specific therapeutic targeting mode. Thus, providing a widened avenue to ponder the allosteric sites or the isoform selectivity conformations for targeting LIMK2 in various disease conditions.
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Belviso BD, Mangiatordi GF, Alberga D, Mangini V, Carrozzini B, Caliandro R. Structural Characterization of the Full-Length Anti-CD20 Antibody Rituximab. Front Mol Biosci 2022; 9:823174. [PMID: 35480889 PMCID: PMC9037831 DOI: 10.3389/fmolb.2022.823174] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Accepted: 03/14/2022] [Indexed: 01/05/2023] Open
Abstract
Rituximab, a murine–human chimera, is the first monoclonal antibody (mAb) developed as a therapeutic agent to target CD20 protein. Its Fab domain and its interaction with CD20 have been extensively studied and high-resolution atomic models obtained by X-ray diffraction or cryo-electron microscopy are available. However, the structure of the full-length antibody is still missing as the inherent protein flexibility hampers the formation of well-diffracting crystals and the reconstruction of 3D microscope images. The global structure of rituximab from its dilute solution is here elucidated by small-angle X-ray scattering (SAXS). The limited data resolution achievable by this technique has been compensated by intensive computational modelling that led to develop a new and effective procedure to characterize the average mAb conformation as well as that of the single domains. SAXS data indicated that rituximab adopts an asymmetric average conformation in solution, with a radius of gyration and a maximum linear dimension of 52 Å and 197 Å, respectively. The asymmetry is mainly due to an uneven arrangement of the two Fab units with respect to the central stem (the Fc domain) and reflects in a different conformation of the individual units. As a result, the Fab elbow angle, which is a crucial determinant for antigen recognition and binding, was found to be larger (169°) in the more distant Fab unit than that in the less distant one (143°). The whole flexibility of the antibody has been found to strongly depend on the relative inter-domain orientations, with one of the Fab arms playing a major role. The average structure and the amount of flexibility has been studied in the presence of different buffers and additives, and monitored at increasing temperature, up to the complete unfolding of the antibody. Overall, the structural characterization of rituximab can help in designing next-generation anti-CD20 antibodies and finding more efficient routes for rituximab production at industrial level.
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Affiliation(s)
| | | | | | | | | | - Rocco Caliandro
- Institute of Crystallography, CNR, Bari, Italy
- *Correspondence: Rocco Caliandro,
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Communication pathways bridge local and global conformations in an IgG4 antibody. Sci Rep 2021; 11:23197. [PMID: 34853348 PMCID: PMC8636491 DOI: 10.1038/s41598-021-02323-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Accepted: 11/15/2021] [Indexed: 12/15/2022] Open
Abstract
The affinity of an antibody for its antigen is primarily determined by the specific sequence and structural arrangement of the complementarity-determining regions (CDRs). Recent evidence, however, points toward a nontrivial relation between the CDR and distal sites: variations in the binding strengths have been observed upon mutating residues separated from the paratope by several nanometers, thus suggesting the existence of a communication network within antibodies, whose extension and relevance might be deeper than insofar expected. In this work, we test this hypothesis by means of molecular dynamics (MD) simulations of the IgG4 monoclonal antibody pembrolizumab, an approved drug that targets the programmed cell death protein 1 (PD-1). The molecule is simulated in both the apo and holo states, totalling 4 μs of MD trajectory. The analysis of these simulations shows that the bound antibody explores a restricted range of conformations with respect to the apo one, and that the global conformation of the molecule correlates with that of the CDR. These results support the hypothesis that pembrolizumab featues a multi-scale hierarchy of intertwined global and local conformational changes. The analysis pipeline developed in this work is general, and it can help shed further light on the mechanistic aspects of antibody function.
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Three-dimensional structure of human cyclooxygenase (hCOX)-1. Sci Rep 2021; 11:4312. [PMID: 33619313 PMCID: PMC7900114 DOI: 10.1038/s41598-021-83438-z] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Accepted: 02/02/2021] [Indexed: 12/11/2022] Open
Abstract
The beneficial effects of Cyclooxygenases (COX) inhibitors on human health have been known for thousands of years. Nevertheless, COXs, particularly COX-1, have been linked to a plethora of human diseases such as cancer, heart failure, neurological and neurodegenerative diseases only recently. COXs catalyze the first step in the biosynthesis of prostaglandins (PGs) and are among the most important mediators of inflammation. All published structural work on COX-1 deals with the ovine isoenzyme, which is easier to produce in milligram-quantities than the human enzyme and crystallizes readily. Here, we report the long-sought structure of the human cyclooxygenase-1 (hCOX-1) that we refined to an R/Rfree of 20.82/26.37, at 3.36 Å resolution. hCOX-1 structure provides a detailed picture of the enzyme active site and the residues crucial for inhibitor/substrate binding and catalytic activity. We compared hCOX-1 crystal structure with the ovine COX-1 and human COX-2 structures by using metrics based on Cartesian coordinates, backbone dihedral angles, and solvent accessibility coupled with multivariate methods. Differences and similarities among structures are discussed, with emphasis on the motifs responsible for the diversification of the various enzymes (primary structure, stability, catalytic activity, and specificity). The structure of hCOX-1 represents an essential step towards the development of new and more selective COX-1 inhibitors of enhanced therapeutic potential.
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Muthukumaran S, Sulochana KN, Umashankar V. Structure based design of inhibitory peptides targeting ornithine decarboxylase dimeric interface and in vitro validation in human retinoblastoma Y79 cells. J Biomol Struct Dyn 2020; 39:5261-5275. [PMID: 32597331 DOI: 10.1080/07391102.2020.1785331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Polyamine synthesis in human cells is initiated by catalytic action of Ornithine decarboxylase (ODC) on Ornithine. Elevated levels of polyamines are manifested proliferating cancer cells and are found to promote tumour cell adhesion. Di-flouro methyl orninthine is a known inhibitor of ODC, however its usage is limited due its low affinity quick clearance and incompetent cellular uptake, thus posing a need for potential inhibitors. Currently, peptides are substituting drugs, as these are highly selective, specific and potent. Hence, in this study, the interacting interfaces of native homodimeric form of ODC and its heterodimer with Antizyme were probed to design inhibitory peptides targeting ODC. The designed peptides were validated for structural fitness by extensive molecular dynamics simulations and Circular dichroism studies. Finally, these peptides were validated in Y79 retinoblastoma cells for impact on ODC activity, cytotoxicity cell cycle and cell adhesion. On collective analysis, Peptide3 (Pep 3) and Peptide4 (Pep 4) were found to be potentially targeting ODC, as these peptides showed significant decrease in intracellular polyamine levels, cell adhesion and cell cycle perturbation in Y79 cells. Thus, Pep 3 and Pep 4 shall be favourably considered as therapeutic agents for targeting ODC mediated proliferation in retinoblastoma.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Sivashanmugam Muthukumaran
- Centre for Bioinformatics, Kamalnayan Bajaj Institute for Research in Vision and Ophthalmology, Vision Research Foundation, Chennai, India.,School of Chemical and Biotechnology, SASTRA Deemed University, Thanjavur, India
| | - K N Sulochana
- R.S. Mehta Jain Department of Biochemistry and Cell Biology, Kamalnayan Bajaj Institute for Research in Vision and Ophthalmology, Vision Research Foundation, Chennai, India
| | - Vetrivel Umashankar
- Centre for Bioinformatics, Kamalnayan Bajaj Institute for Research in Vision and Ophthalmology, Vision Research Foundation, Chennai, India.,National Institute of Traditional Medicine, Indian Council of Medical Research, Department of Health Research (Govt. of India), Belagavi, India
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Sasidharan S, Saudagar P. Concerted motion of structure and active site charge is required for tyrosine aminotransferase activity in Leishmania parasite. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2020; 232:118133. [PMID: 32086045 DOI: 10.1016/j.saa.2020.118133] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Revised: 02/03/2020] [Accepted: 02/04/2020] [Indexed: 06/10/2023]
Abstract
Leishmania donovani tyrosine aminotransferase (LdTAT) is an essential enzyme that catalyzes the first step of amino acid catabolism. To understand LdTAT activity at different pH, molecular dynamics simulations were performed and trajectory and T-pad analysis pad were conducted. Fluorescence spectroscopy of LdTAT at various pH was measured to understand structural stability. UV studies on PLP were performed to determine the binding of the enzyme to cofactor PLP at different pH. The MD simulations showed that the structure of LdTAT was stable and no structural denaturation was observed at pH 2, 7 and 12. LdTAT exhibited the highest activity at pH -8 and fluorescent spectroscopy also corroborated by exhibiting the highest intensity at pH -8. Moreover, no structural denaturation was observed during the pH gradient. UV studies concluded that the aldimine bond forms only around neutral pH and redshift was observed on enzyme binding. From our observation, we hypothesize that the activity of LdTAT is a close interplay between the structure and charges of K286 and PLP. This study may provide significant insight into understanding parasitic enzymes like LdTAT during the life-cycle of Leishmania parasite. Knowledge of such enzyme mechanisms can pave the way for the design and delivery of enzyme-specific inhibitors.
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Affiliation(s)
- Santanu Sasidharan
- Department of Biotechnology, National Institute of Technology, Warangal, 506004, Telangana, India
| | - Prakash Saudagar
- Department of Biotechnology, National Institute of Technology, Warangal, 506004, Telangana, India.
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Jayaraman M, Rajendra SK, Ramadas K. Structural insight into conformational dynamics of non-active site mutations in KasA: A Mycobacterium tuberculosis target protein. Gene 2019; 720:144082. [DOI: 10.1016/j.gene.2019.144082] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Revised: 08/23/2019] [Accepted: 08/26/2019] [Indexed: 10/26/2022]
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Bütepage M, Krieg S, Eckei L, Li J, Rossetti G, Verheugd P, Lüscher B. Assessment of Intracellular Auto-Modification Levels of ARTD10 Using Mono-ADP-Ribose-Specific Macrodomains 2 and 3 of Murine Artd8. Methods Mol Biol 2019; 1813:41-63. [PMID: 30097860 DOI: 10.1007/978-1-4939-8588-3_4] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Mono-ADP-ribosylation is a posttranslational modification, which is catalyzed in cells by certain members of the ADP-ribosyltransferase diphtheria toxin-like family (ARTD) of ADP-ribosyltransferases (aka PARP enzymes). It involves the transfer of a single residue of ADP-ribose (ADPr) from the cofactor NAD+ onto substrate proteins. Although 12 of the 17 members of the ARTD family have been defined as mono-ARTDs in in vitro assays, relatively little is known about their exact cellular functions. A major challenge is the detection of mono-ADP-ribosylated (MARylated) proteins in cells as no antibodies are available that detect exclusively MARylated proteins. As an alternative to classical antibodies, the MAR-specific binding domains macro2 and macro3 of Artd8 can be utilized alone or in combination, to demonstrate intracellular auto-modification levels of ARTD10 in cells in both co-immunoprecipitation and co-localization experiments. Here we demonstrate that different macrodomain constructs of human ARTD8 and murine Artd8, alone or in combination, exert differences with regard to their interaction with ARTD10 in cells. Precisely, while the macrodomains of murine Artd8 interacted with ARTD10 in cells in a MARylation-dependent manner, the macrodomains of human ARTD8 interacted with ARTD10 independent of its catalytic activity. Moreover, we show that a combination of macro2 and macro3 of murine Artd8 was recruited more efficiently to ARTD10 during co-localization experiments compared to the single domains. Therefore, murine Artd8 macrodomain constructs can serve as a tool to evaluate intracellular ARTD10 auto-modification levels using the described methods, while the human ARTD8 macrodomains are less suited because of ADPr-independent binding to ARTD10. Protocols for co-immunoprecipitation and co-localization experiments are described in detail.
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Affiliation(s)
- Mareike Bütepage
- Institute of Biochemistry and Molecular Biology, Medical School, RWTH Aachen University, Aachen, Germany.
| | - Sarah Krieg
- Institute of Biochemistry and Molecular Biology, Medical School, RWTH Aachen University, Aachen, Germany
| | - Laura Eckei
- Institute of Biochemistry and Molecular Biology, Medical School, RWTH Aachen University, Aachen, Germany
| | - Jinyu Li
- College of Chemistry, Fuzhou University, Fuzhou, China
| | - Giulia Rossetti
- Computational Biomedicine, Institute for Advanced Simulation IAS-5 and Institute of Neuroscience and Medicine INM-9, Jülich, Germany.,Jülich Supercomputing Centre, Jülich, Germany.,Department of Oncology, Hematology and Stem Cell Transplantation, Medical School, RWTH Aachen University, Aachen, Germany
| | - Patricia Verheugd
- Institute of Biochemistry and Molecular Biology, Medical School, RWTH Aachen University, Aachen, Germany
| | - Bernhard Lüscher
- Institute of Biochemistry and Molecular Biology, Medical School, RWTH Aachen University, Aachen, Germany.
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Tarenzi T, Calandrini V, Potestio R, Carloni P. Open-Boundary Molecular Mechanics/Coarse-Grained Framework for Simulations of Low-Resolution G-Protein-Coupled Receptor-Ligand Complexes. J Chem Theory Comput 2019; 15:2101-2109. [PMID: 30763087 PMCID: PMC6433333 DOI: 10.1021/acs.jctc.9b00040] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Indexed: 12/18/2022]
Abstract
G-protein-coupled receptors (GPCRs) constitute as much as 30% of the overall proteins targeted by FDA-approved drugs. However, paucity of structural experimental information and low sequence identity between members of the family impair the reliability of traditional docking approaches and atomistic molecular dynamics simulations for in silico pharmacological applications. We present here a dual-resolution approach tailored for such low-resolution models. It couples a hybrid molecular mechanics/coarse-grained (MM/CG) scheme, previously developed by us for GPCR-ligand complexes, with a Hamiltonian-based adaptive resolution scheme (H-AdResS) for the solvent. This dual-resolution approach removes potentially inaccurate atomistic details from the model while building a rigorous statistical ensemble-the grand canonical one-in the high-resolution region. We validate the method on a well-studied GPCR-ligand complex, for which the 3D structure is known, against atomistic simulations. This implementation paves the way for future accurate in silico studies of low-resolution ligand/GPCRs models.
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Affiliation(s)
- Thomas Tarenzi
- Computation-based Science and Technology Research Center CaSToRC , The Cyprus Institute , 20 Konstaninou Kavafi Street , 2121 Aglantzia, Nicosia , Cyprus
- Departments of Physics , Faculty of Mathematics, Computer Science and Natural Sciences, Aachen University , Otto-Blumenthal Straße , 52062 Aachen , Germany
- Computational Biomedicine, Institute for Advanced Simulations IAS-5 and Institute of Neuroscience and Medicine INM-9 , Forschungszentrum Jülich , 52428 Jülich , Germany
| | - Vania Calandrini
- Computational Biomedicine, Institute for Advanced Simulations IAS-5 and Institute of Neuroscience and Medicine INM-9 , Forschungszentrum Jülich , 52428 Jülich , Germany
| | - Raffaello Potestio
- Department of Physics , University of Trento , via Sommarive 14 Povo , Trento 38123 , Italy
- INFN-TIFPA, Trento Institute for Fundamental Physics and Applications , I-38123 Trento , Italy
| | - Paolo Carloni
- Departments of Physics , Faculty of Mathematics, Computer Science and Natural Sciences, Aachen University , Otto-Blumenthal Straße , 52062 Aachen , Germany
- Computational Biomedicine, Institute for Advanced Simulations IAS-5 and Institute of Neuroscience and Medicine INM-9 , Forschungszentrum Jülich , 52428 Jülich , Germany
- JARA-HPC, Jülich Supercomputing Center , Forschungszentrum Jülich , 52428 Jülich , Germany
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Bochicchio A, Krepl M, Yang F, Varani G, Sponer J, Carloni P. Molecular basis for the increased affinity of an RNA recognition motif with re-engineered specificity: A molecular dynamics and enhanced sampling simulations study. PLoS Comput Biol 2018; 14:e1006642. [PMID: 30521520 PMCID: PMC6307825 DOI: 10.1371/journal.pcbi.1006642] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Revised: 12/27/2018] [Accepted: 11/13/2018] [Indexed: 12/25/2022] Open
Abstract
The RNA recognition motif (RRM) is the most common RNA binding domain across eukaryotic proteins. It is therefore of great value to engineer its specificity to target RNAs of arbitrary sequence. This was recently achieved for the RRM in Rbfox protein, where four mutations R118D, E147R, N151S, and E152T were designed to target the precursor to the oncogenic miRNA 21. Here, we used a variety of molecular dynamics-based approaches to predict specific interactions at the binding interface. Overall, we have run approximately 50 microseconds of enhanced sampling and plain molecular dynamics simulations on the engineered complex as well as on the wild-type Rbfox·pre-miRNA 20b from which the mutated systems were designed. Comparison with the available NMR data on the wild type molecules (protein, RNA, and their complex) served to establish the accuracy of the calculations. Free energy calculations suggest that further improvements in affinity and selectivity are achieved by the S151T replacement. RNA is an outstanding target for oncological intervention. Engineering the most common RNA binding motif in human proteins (called RRM) so as to bind to a specific RNA has an enormous pharmacological potential. Yet, it is highly non trivial to design RRM-bearing protein variants with RNA selectivity and affinity sufficiently high for clinical applications. Here we present an extensive molecular simulation study which shed light on the exquisite molecular recognition of the empirically-engineered complex between the RRM-bearing protein Rbfox and its RNA target pre-miR21. The simulations allow predicting a variant, the S151T, which may lead to further enhancement of selectivity and affinity for pre-miR21.
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Affiliation(s)
- Anna Bochicchio
- Computational Biomedicine, Institute for Advanced Simulation IAS-5 and Institute of Neuroscience and Medicine INM-9, Forschungszentrum Jülich, Jülich, Germany
| | - Miroslav Krepl
- Institute of Biophysics of the Czech Academy of Sciences, Brno, Czech Republic
- * E-mail: (MK); (PC)
| | - Fan Yang
- Department of Chemistry, University of Washington, Seattle, Washington, United States of America
| | - Gabriele Varani
- Department of Chemistry, University of Washington, Seattle, Washington, United States of America
| | - Jiri Sponer
- Institute of Biophysics of the Czech Academy of Sciences, Brno, Czech Republic
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University Olomouc, Olomouc, Czech Republic
| | - Paolo Carloni
- Computational Biomedicine, Institute for Advanced Simulation IAS-5 and Institute of Neuroscience and Medicine INM-9, Forschungszentrum Jülich, Jülich, Germany
- JARA-HPC, Jülich Supercomputing Centre, Forschungszentrum Jülich GmbH, Jülich, Germany
- * E-mail: (MK); (PC)
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Cukier RI. Conformational Ensembles Exhibit Extensive Molecular Recognition Features. ACS OMEGA 2018; 3:9907-9920. [PMID: 31459119 PMCID: PMC6644992 DOI: 10.1021/acsomega.8b00898] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Accepted: 08/14/2018] [Indexed: 06/10/2023]
Abstract
Intrinsically disordered proteins (IDPs) are important for signaling and regulatory pathways. In contrast to folded proteins, they sample a diverse conformational space. IDPs have residue ranges within a sequence that have been referred to as molecular recognition features (MoRFs). A MoRF can be viewed as contiguous residues exhibiting a conformational disorder that become ordered upon binding to another protein or ligand. In this work, we introduce a structural characterization of MoRFs based on entropy and mutual information (MI). In this view, a MoRF is a set of contiguous residues that exhibit a large entropy (from rotameric residue sampling) and large MI, the latter indicating a dependence among the residues' rotameric sampling comprising the MoRF. The methodology is first applied to a number of ubiquitin ensembles that were obtained based on nuclear magnetic resonance experiments. One is a denatured Ub ensemble that has a large entropy for various unitSizes (number of contiguous residues) but essentially zero MI, indicting no dependence among the residue rotamer sampling. Another ensemble does exhibit extensive regions along the sequence where there are MoRFs centered on nonsecondary structure regions. The MoRFs are present for unitSizes 2-10. That a substantial number of MoRFs are present in Ub strongly suggests a conformational selection mechanism for this protein. Two additional ensembles for the cyclin-dependent kinase inhibitor Sic1 and for the amyloid protein α-synuclein, which have been shown to be IDPs, are also analyzed. Both exhibit MoRF-like character.
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14
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Zeng J, Guareschi R, Damre M, Cao R, Kless A, Neumaier B, Bauer A, Giorgetti A, Carloni P, Rossetti G. Structural Prediction of the Dimeric Form of the Mammalian Translocator Membrane Protein TSPO: A Key Target for Brain Diagnostics. Int J Mol Sci 2018; 19:E2588. [PMID: 30200318 PMCID: PMC6165245 DOI: 10.3390/ijms19092588] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Revised: 08/21/2018] [Accepted: 08/28/2018] [Indexed: 11/17/2022] Open
Abstract
Positron emission tomography (PET) radioligands targeting the human translocator membrane protein (TSPO) are broadly used for the investigations of neuroinflammatory conditions associated with neurological disorders. Structural information on the mammalian protein homodimers-the suggested functional state of the protein-is limited to a solid-state nuclear magnetic resonance (NMR) study and to a model based on the previously-deposited solution NMR structure of the monomeric mouse protein. Computational studies performed here suggest that the NMR-solved structure in the presence of detergents is not prone to dimer formation and is furthermore unstable in its native membrane environment. We, therefore, propose a new model of the functionally-relevant dimeric form of the mouse protein, based on a prokaryotic homologue. The model, fully consistent with solid-state NMR data, is very different from the previous predictions. Hence, it provides, for the first time, structural insights into this pharmaceutically-important target which are fully consistent with experimental data.
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Affiliation(s)
- Juan Zeng
- Institute for Advanced Simulations (IAS)-5/Institute for Neuroscience and Medicine (INM)-9, Forschungszentrum Jülich, 52428 Jülich, Germany.
- Laboratory of Computational Chemistry and Drug Design, Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, 518055 Shenzhen, China.
| | - Riccardo Guareschi
- Institute for Advanced Simulations (IAS)-5/Institute for Neuroscience and Medicine (INM)-9, Forschungszentrum Jülich, 52428 Jülich, Germany.
| | - Mangesh Damre
- Department of Biotechnology, University of Verona, Strada Le Grazie 15, 37134 Verona, Italy.
- Neurobiology, International School for Advanced Studies (SISSA), 34136 Trieste, Italy.
| | - Ruyin Cao
- Institute for Advanced Simulations (IAS)-5/Institute for Neuroscience and Medicine (INM)-9, Forschungszentrum Jülich, 52428 Jülich, Germany.
| | - Achim Kless
- Grünenthal Innovation, Translational Science & Intelligence, Grünenthal GmbH, 52078 Aachen, Germany.
| | - Bernd Neumaier
- Institute for Neuroscience and Medicine (INM)-5, Forschungszentrum Jülich, 52428 Jülich, Germany.
| | - Andreas Bauer
- Institute for Neuroscience and Medicine (INM)-2, Forschungszentrum Jülich, 52428 Jülich, Germany.
| | - Alejandro Giorgetti
- Institute for Advanced Simulations (IAS)-5/Institute for Neuroscience and Medicine (INM)-9, Forschungszentrum Jülich, 52428 Jülich, Germany.
- Department of Biotechnology, University of Verona, Strada Le Grazie 15, 37134 Verona, Italy.
| | - Paolo Carloni
- Institute for Advanced Simulations (IAS)-5/Institute for Neuroscience and Medicine (INM)-9, Forschungszentrum Jülich, 52428 Jülich, Germany.
- RWTH Aachen University, Department of Physics, 52078 Aachen, Germany.
| | - Giulia Rossetti
- Institute for Advanced Simulations (IAS)-5/Institute for Neuroscience and Medicine (INM)-9, Forschungszentrum Jülich, 52428 Jülich, Germany.
- Jülich Supercomputing Center (JSC), Forschungszentrum Jülich, 52428 Jülich, Germany.
- University Hospital Aachen, RWTH Aachen University, 52078 Aachen, Germany.
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15
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Demystifying the pH dependent conformational changes of human heparanase pertaining to structure–function relationships: an in silico approach. J Comput Aided Mol Des 2018; 32:821-840. [DOI: 10.1007/s10822-018-0131-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Accepted: 07/04/2018] [Indexed: 10/28/2022]
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16
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Caliandro R, Nico G, Tiscia G, Favuzzi G, De Stefano V, Rossi E, Margaglione M, Grandone E. Structural analysis of protein Z gene variants in patients with foetal losses. Thromb Haemost 2017; 110:534-42. [DOI: 10.1160/th13-01-0005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2013] [Accepted: 05/23/2013] [Indexed: 11/05/2022]
Abstract
SummaryThe role of protein Z (PZ) in the etiology of human disorders is unclear. A number of PZ gene variants, sporadic or polymorphic and found exclusively in the serine protease domain, have been observed. Crystal structures of PZ in complex with the PZ-dependent inhibitor (PZI) have been recently obtained. The aim of this study was a structural investigation of the serine protease PZ domain, aiming at finding common traits across disease-linked mutations. We performed 10–20 ns molecular dynamics for each of the observed PZ mutants to investigate their structure in aqueous solution. Simulation data were processed by novel tools to analyse the residue-by-residue backbone flexibility. Results showed that sporadic mutations are associated with anomalous flexibility of residues belonging to specific regions. Among them, the most important is a loop region which is in contact with the longest helix of PZI. Other regions have been identified, which hold anomalous flexibility associated with potentially protective gene variants. In conclusion, a possible interpretation of effects associated with observed gene variants is provided. The exploration of PZ/PZI interactions seems essential in explaining these effects.
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17
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Pesce L, Calandrini V, Marjault HB, Lipper CH, Rossetti G, Mittler R, Jennings PA, Bauer A, Nechushtai R, Carloni P. Molecular Dynamics Simulations of the [2Fe-2S] Cluster-Binding Domain of NEET Proteins Reveal Key Molecular Determinants That Induce Their Cluster Transfer/Release. J Phys Chem B 2017; 121:10648-10656. [PMID: 29086562 PMCID: PMC5713697 DOI: 10.1021/acs.jpcb.7b10584] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The NEET proteins are a novel family of iron-sulfur proteins characterized by an unusual three cysteine and one histidine coordinated [2Fe-2S] cluster. Aberrant cluster release, facilitated by the breakage of the Fe-N bond, is implicated in a variety of human diseases, including cancer. Here, the molecular dynamics in the multi-microsecond timescale, along with quantum chemical calculations, on two representative members of the family (the human NAF-1 and mitoNEET proteins), show that the loss of the cluster is associated with a dramatic decrease in secondary and tertiary structure. In addition, the calculations provide a mechanism for cluster release and clarify, for the first time, crucial differences existing between the two proteins, which are reflected in the experimentally observed difference in the pH-dependent cluster reactivity. The reliability of our conclusions is established by an extensive comparison with the NMR data of the solution proteins, in part measured in this work.
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Affiliation(s)
- Luca Pesce
- Computational Biomedicine Section, Institute of Advanced Simulation IAS-5 and Institute of Neuroscience and Medicine INM-9, Forschungszentrum Jülich GmbH , 52425 Jülich, Germany
| | - Vania Calandrini
- Computational Biomedicine Section, Institute of Advanced Simulation IAS-5 and Institute of Neuroscience and Medicine INM-9, Forschungszentrum Jülich GmbH , 52425 Jülich, Germany
| | - Henri-Baptiste Marjault
- The Alexander Silberman Life Science Institute and the Wolfson Center for Applied Structural Biology, The Hebrew University of Jerusalem, Edmond J. Safra Campus at Givat Ram , 91904 Jerusalem, Israel
| | - Colin H Lipper
- Departments of Chemistry and Biochemistry, University of California San Diego , La Jolla, 92093 San Diego, California, United States of America
| | - Gulia Rossetti
- Computational Biomedicine Section, Institute of Advanced Simulation IAS-5 and Institute of Neuroscience and Medicine INM-9, Forschungszentrum Jülich GmbH , 52425 Jülich, Germany.,Division Computational Science - Simulation Laboratory Biology, Jülich Supercomputing Centre (JSC), Forschungszentrum Jülich GmbH , 52428 Jülich, Germany.,Department of Oncology, Hematology and Stem Cell Transplantation, University Hospital Aachen, RWTH Aachen University , 52074 Aachen, Germany
| | - Ron Mittler
- Department of Biological Sciences and BioDiscovery Institute, University of North Texas , 76203 Denton, Texas, United States of America
| | - Patricia A Jennings
- Departments of Chemistry and Biochemistry, University of California San Diego , La Jolla, 92093 San Diego, California, United States of America
| | - Andreas Bauer
- Molecular Organisation of the Brain Molecular Neuroimaging, Institute of Neuroscience and Medicine INM-2, Forschungszentrum Jülich GmbH , 52428 Jülich, Germany
| | - Rachel Nechushtai
- The Alexander Silberman Life Science Institute and the Wolfson Center for Applied Structural Biology, The Hebrew University of Jerusalem, Edmond J. Safra Campus at Givat Ram , 91904 Jerusalem, Israel
| | - Paolo Carloni
- Computational Biomedicine Section, Institute of Advanced Simulation IAS-5 and Institute of Neuroscience and Medicine INM-9, Forschungszentrum Jülich GmbH , 52425 Jülich, Germany.,JARA-HPC , 52428 Jülich, Germany
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18
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Tarenzi T, Calandrini V, Potestio R, Giorgetti A, Carloni P. Open Boundary Simulations of Proteins and Their Hydration Shells by Hamiltonian Adaptive Resolution Scheme. J Chem Theory Comput 2017; 13:5647-5657. [PMID: 28992702 DOI: 10.1021/acs.jctc.7b00508] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The recently proposed Hamiltonian adaptive resolution scheme (H-AdResS) allows the performance of molecular simulations in an open boundary framework. It allows changing, on the fly, the resolution of specific subsets of molecules (usually the solvent), which are free to diffuse between the atomistic region and the coarse-grained reservoir. So far, the method has been successfully applied to pure liquids. Coupling the H-AdResS methodology to hybrid models of proteins, such as the molecular mechanics/coarse-grained (MM/CG) scheme, is a promising approach for rigorous calculations of ligand binding free energies in low-resolution protein models. Toward this goal, here we apply for the first time H-AdResS to two atomistic proteins in dual-resolution solvent, proving its ability to reproduce structural and dynamic properties of both the proteins and the solvent, as obtained from atomistic simulations.
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Affiliation(s)
- Thomas Tarenzi
- Computation-Based Science and Technology Research Center CaSToRC, The Cyprus Institute , 20 Konstantinou Kavafi Street, 2121, Aglantzia, Nicosia, Cyprus
- Department of Physics, Faculty of Mathematics, Computer Science and Natural Sciences, Aachen University , Otto-Blumenthal-Straße, 52074 Aachen, Germany
| | - Vania Calandrini
- Computational Biomedicine, Institute for Advanced Simulation IAS-5, and Institute of Neuroscience and Medicine INM-9, Forschungszentrum Jülich , 52425 Jülich, Germany
| | - Raffaello Potestio
- Max Planck Institute for Polymer Research , Ackermannweg 10, 55128 Mainz, Germany
| | - Alejandro Giorgetti
- Computational Biomedicine, Institute for Advanced Simulation IAS-5, and Institute of Neuroscience and Medicine INM-9, Forschungszentrum Jülich , 52425 Jülich, Germany
- Department of Biotechnology, University of Verona , Ca' Vignal 1, Strada Le Grazie 15, 37134 Verona, Italy
| | - Paolo Carloni
- Department of Physics, Faculty of Mathematics, Computer Science and Natural Sciences, Aachen University , Otto-Blumenthal-Straße, 52074 Aachen, Germany
- Computational Biomedicine, Institute for Advanced Simulation IAS-5, and Institute of Neuroscience and Medicine INM-9, Forschungszentrum Jülich , 52425 Jülich, Germany
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19
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Borkotoky S, Kumar Meena C, Bhalerao GM, Murali A. An in-silico glimpse into the pH dependent structural changes of T7 RNA polymerase: a protein with simplicity. Sci Rep 2017; 7:6290. [PMID: 28740191 PMCID: PMC5524818 DOI: 10.1038/s41598-017-06586-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Accepted: 06/14/2017] [Indexed: 11/24/2022] Open
Abstract
The capability of performing an array of functions with its single subunit structure makes T7 RNA polymerase (T7RNAP) as one of the simplest yet attractive target for various investigations ranging from structure determinations to several biological tests. In this study, with the help of molecular dynamics (MD) calculations and molecular docking, we investigated the effect of varying pH conditions on conformational flexibility of T7RNAP. We also studied its effect on the interactions with a well established inhibitor (heparin), substrate GTP and T7 promoter of T7RNAP. The simulation studies were validated with the help of three dimensional reconstructions of the polymerase at different pH environments using transmission electron microscopy and single particle analysis. On comparing the simulated structures, it was observed that the structure of T7RNAP changes considerably and interactions with its binding partners also changes as the pH shifts from basic to acidic. Further, it was observed that the C-terminal end plays a vital role in the inefficiency of the polymerase at low pH. Thus, this in-silico study may provide a significant insight into the structural investigations on T7RNAP as well as in designing potent inhibitors against it in varying pH environments.
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Affiliation(s)
- Subhomoi Borkotoky
- Centre for Bioinformatics, School of Life Sciences, Pondicherry University, Puducherry, 605014, India
| | - Chetan Kumar Meena
- Centre for Bioinformatics, School of Life Sciences, Pondicherry University, Puducherry, 605014, India
| | - Gopalkrishna M Bhalerao
- UGC-DAE Consortium for Scientific Research Kalpakkam Node, Kokilamedu, Tamilnadu, 603104, India
| | - Ayaluru Murali
- Centre for Bioinformatics, School of Life Sciences, Pondicherry University, Puducherry, 605014, India.
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20
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Topno NS, Kannan M, Krishna R. Mechanistic insights into the activity of Ptf1-p48 (pancreas transcription factor 1a): probing the interactions levels of Ptf1-p48 with E2A-E47 (transcription factor E2-alpha) and ID3 (inhibitor of DNA binding 3). J Biomol Struct Dyn 2017; 36:1834-1852. [PMID: 28571517 DOI: 10.1080/07391102.2017.1336487] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Ptf1-p48 (Pancreas specific transcription factor 1a) is transcription regulatory protein known for the activation of exocrine specific genes. Downregulation of its expression formulates early stages of pancreatic adenocarcinoma as deduced by its association with oncogenic bHLH (Basic Helix-Loop-Helix) protein ID3 (Inhibitor of DNA binding 3) protein whose overexpression induces cytoplasmic mislocalization of Ptf1-p48. The precise mechanism and/or functional role of Ptf1-p48in promoting pancreatic cancer is vague. The structural features of the Ptf1-p48 and its dimerization with E47 (Transcription factor E2-alpha) and ID3 mediated by their HLH (Helix-Loop-Helix) domain were perceived through MD (Molecular Dynamics) simulations of 50 ns. The interactions formed by the HLH domain in both Ptf1-E47 and Ptf1-ID3 complexes are favored by the synergistic movement of their domain helices. Accordingly, in the Ptf1-E47 complex α7 of Ptf1-p48 and α1 helix of E47 along with the loop residues of their HLH domain exhibit transitions marked by inward movement toward each other and forms polar and charged interactions. In the Ptf1-ID3 complex, α8 of Ptf1-p48 moves toward the α3 helix of ID3 and forms hydrogen bonds. The interface analysis also reveals better interface in the Ptf1-p48 complex than the Ptf1-ID3 evident by energetics and number of hydrogen bonds. The interactions in each of these complexes, supported by angular displacement and mode vector analyzes, comprehensibly describe the considerable structural changes induced upon dimer formation. It thereby gives an insight into the interfaces that could help in designing of potential inhibitors for ID3 to curb the cancer cell growth.
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Affiliation(s)
- Nishith Saurav Topno
- a Centre for Bioinformatics, School of Life Sciences, Pondicherry University , Puducherry , India
| | - Muthu Kannan
- b CAS in Crystallography and Biophysics , University of Madras , Chennai , India
| | - Ramadas Krishna
- a Centre for Bioinformatics, School of Life Sciences, Pondicherry University , Puducherry , India
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21
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Borkotoky S, Murali A. A computational assessment of pH-dependent differential interaction of T7 lysozyme with T7 RNA polymerase. BMC STRUCTURAL BIOLOGY 2017; 17:7. [PMID: 28545576 PMCID: PMC5445346 DOI: 10.1186/s12900-017-0077-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Accepted: 05/17/2017] [Indexed: 01/16/2023]
Abstract
Background T7 lysozyme (T7L), also known as N-acetylmuramoyl-L-alanine amidase, is a T7 bacteriophage gene product. It involves two functions: It can cut amide bonds in the bacterial cell wall and interacts with T7 RNA polymerase (T7RNAP) as a part of transcription inhibition. In this study, with the help of molecular dynamics (MD) calculations and computational interaction studies, we investigated the effect of varying pH conditions on conformational flexibilities of T7L and their influence on T7RNAP -T7L interactions. Results From the MD studies of the T7L at three different pH strengths viz. 5, neutral and 7.9 it was observed that T7L structure at pH 5 exhibited less stable nature with more residue level fluctuations, decrease of secondary structural elements and less compactness as compared to its counterparts: neutral pH and pH 7.9. The T-pad analysis of the MD trajectories identified local fluctuations in few residues that influenced the conformational differences in three pH strengths. From the docking of the minimum energy representative structures of T7L at different pH strengths (obtained from the free energy landscape analysis) with T7RNAP structures at same pH strengths, we saw strong interaction patterns at pH 7.9 and pH 5. The MD analysis of these complexes also confirmed the observations of docking study. From the combined in silico studies, it was observed that there are conformational changes in N-terminal and near helix 1 of T7L at different pH strengths, which are involved in the T7RNAP interaction, thereby varying the interaction pattern. Conclusion Since T7L has been used for developing novel therapeutics and T7RNAP one of the most biologically useful protein in both in-vitro and in vivo experiments, this in silico study of pH dependent conformational differences in T7L and the differential interaction with T7RNAP at different pH can provide a significant insight into the structural investigations on T7L and T7RNAP in varying pH environments. Electronic supplementary material The online version of this article (doi:10.1186/s12900-017-0077-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Subhomoi Borkotoky
- Centre for Bioinformatics, School of Life Sciences, Pondicherry University, Puducherry, 605014, India
| | - Ayaluru Murali
- Centre for Bioinformatics, School of Life Sciences, Pondicherry University, Puducherry, 605014, India.
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22
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Enniatin and Beauvericin Biosynthesis in Fusarium Species: Production Profiles and Structural Determinant Prediction. Toxins (Basel) 2017; 9:toxins9020045. [PMID: 28125067 PMCID: PMC5331425 DOI: 10.3390/toxins9020045] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Revised: 01/16/2017] [Accepted: 01/18/2017] [Indexed: 11/17/2022] Open
Abstract
Members of the fungal genus Fusarium can produce numerous secondary metabolites, including the nonribosomal mycotoxins beauvericin (BEA) and enniatins (ENNs). Both mycotoxins are synthesized by the multifunctional enzyme enniatin synthetase (ESYN1) that contains both peptide synthetase and S-adenosyl-l-methionine-dependent N-methyltransferase activities. Several Fusarium species can produce ENNs, BEA or both, but the mechanism(s) enabling these differential metabolic profiles is unknown. In this study, we analyzed the primary structure of ESYN1 by sequencing esyn1 transcripts from different Fusarium species. We measured ENNs and BEA production by ultra-performance liquid chromatography coupled with photodiode array and Acquity QDa mass detector (UPLC-PDA-QDa) analyses. We predicted protein structures, compared the predictions by multivariate analysis methods and found a striking correlation between BEA/ENN-producing profiles and ESYN1 three-dimensional structures. Structural differences in the β strand's Asn789-Ala793 and His797-Asp802 portions of the amino acid adenylation domain can be used to distinguish BEA/ENN-producing Fusarium isolates from those that produce only ENN.
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23
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Vadlamudi Y, Muthu K, M. SK. Structural exploration of acid sphingomyelinase at different physiological pH through molecular dynamics and docking studies. RSC Adv 2016. [DOI: 10.1039/c6ra16584b] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Acid sphingomyelinase (ASM) hydrolysis the sphingomyelin at physiological pH 5.0 and subsequently leads to ceramide production.
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Affiliation(s)
| | - Kannan Muthu
- Centre for Bioinformatics
- Pondicherry University
- Pondicherry 605014
- India
| | - Suresh Kumar M.
- Centre for Bioinformatics
- Pondicherry University
- Pondicherry 605014
- India
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24
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Topno NS, Kannan M, Krishna R. Interacting mechanism of ID3 HLH domain towards E2A/E12 transcription factor - An Insight through molecular dynamics and docking approach. Biochem Biophys Rep 2015; 5:180-190. [PMID: 28955822 PMCID: PMC5600450 DOI: 10.1016/j.bbrep.2015.12.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2015] [Revised: 11/24/2015] [Accepted: 12/01/2015] [Indexed: 10/29/2022] Open
Abstract
Inhibitor of DNA binding protein 3 (ID3) has long been characterized as an oncogene that implicates its functional role through its Helix-Loop-Helix (HLH) domain upon protein-protein interaction. An insight into the dimerization brought by this domain helps in identifying the key residues that favor the mechanism behind it. Molecular dynamics (MD) simulations were performed for the HLH proteins ID3 and Transcription factor E2-alpha (E2A/E12) and their ensemble complex (ID3-E2A/E12) to gather information about the HLH domain region and its role in the interaction process. Further evaluation of the results by Principal Component Analysis (PCA) and Free Energy Landscape (FEL) helped in revealing residues of E2A/E12: Lys570, Ala595, Val598, and Ile599 and ID3: Glu53, Gln63, and Gln66 buried in their HLH motifs imparting key roles in dimerization process. Furthermore the T-pad analysis results helped in identifying the key fluctuations and conformational transitions using the intrinsic properties of the residues present in the domain region of the proteins thus specifying their crucial role towards molecular recognition. The study provides an insight into the interacting mechanism of the ID3-E2A/E12 complex and maps the structural transitions arising in the essential conformational space indicating the key structural changes within the helical regions of the motif. It thereby describes how the internal dynamics of the proteins might regulate their intrinsic structural features and its subsequent functionality.
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Affiliation(s)
- Nishith Saurav Topno
- Centre for Bioinformatics, School of Life Sciences, Pondicherry University, Puducherry 605014, India
| | - Muthu Kannan
- Centre for Bioinformatics, School of Life Sciences, Pondicherry University, Puducherry 605014, India
| | - Ramadas Krishna
- Centre for Bioinformatics, School of Life Sciences, Pondicherry University, Puducherry 605014, India
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25
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Anishkin A, Vanegas JM, Rogers DM, Lorenzi PL, Chan WK, Purwaha P, Weinstein JN, Sukharev S, Rempe SB. Catalytic Role of the Substrate Defines Specificity of Therapeutic l-Asparaginase. J Mol Biol 2015; 427:2867-85. [DOI: 10.1016/j.jmb.2015.06.017] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Revised: 05/20/2015] [Accepted: 06/26/2015] [Indexed: 12/23/2022]
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26
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Cao R, Rossetti G, Bauer A, CarIoni P. Binding of the Antagonist Caffeine to the Human Adenosine Receptor hA2AR in Nearly Physiological Conditions. PLoS One 2015; 10:e0126833. [PMID: 25992797 PMCID: PMC4439127 DOI: 10.1371/journal.pone.0126833] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Accepted: 04/08/2015] [Indexed: 12/27/2022] Open
Abstract
Lipid composition may significantly affect membrane proteins function, yet its impact on the protein structural determinants is not well understood. Here we present a comparative molecular dynamics (MD) study of the human adenosine receptor type 2A (hA(2A)R) in complex with caffeine--a system of high neuro-pharmacological relevance--within different membrane types. These are POPC, mixed POPC/POPE and cholesterol-rich membranes. 0.8-μs MD simulations unambiguously show that the helical folding of the amphipathic helix 8 depends on membrane contents. Most importantly, the distinct cholesterol binding into the cleft between helix 1 and 2 stabilizes a specific caffeine-binding pose against others visited during the simulation. Hence, cholesterol presence (~33%-50% in synaptic membrane in central nervous system), often neglected in X-ray determination of membrane proteins, affects the population of the ligand binding poses. We conclude that including a correct description of neuronal membranes may be very important for computer-aided design of ligands targeting hA(2A)R and possibly other GPCRs.
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Affiliation(s)
- Ruyin Cao
- German Research School for Simulation Sciences (joint venture of RWTH Aachen University and Forschungszentrum Jülich GmbH), D-52425, Jülich, Germany
- Computational Biomedicine, Institute for Advanced Simulation (IAS-5), Forschungszentrum Jülich GmbH, D-52425, Jülich, Germany
| | - Giulia Rossetti
- German Research School for Simulation Sciences (joint venture of RWTH Aachen University and Forschungszentrum Jülich GmbH), D-52425, Jülich, Germany
- Computational Biomedicine, Institute for Advanced Simulation (IAS-5), Forschungszentrum Jülich GmbH, D-52425, Jülich, Germany
- Institute of Neuroscience and Medicine (INM-9), Forschungszentrum Jülich GmbH, D-52425, Jülich, Germany
- Jülich Supercomputing Centre (JSC), Forschungszentrum Jülich GmbH, D-52425, Jülich, Germany
| | - Andreas Bauer
- Institute of Neuroscience and Medicine (INM-2), Forschungszentrum Jülich GmbH, D-52425, Jülich, Germany
| | - Paolo CarIoni
- German Research School for Simulation Sciences (joint venture of RWTH Aachen University and Forschungszentrum Jülich GmbH), D-52425, Jülich, Germany
- Computational Biomedicine, Institute for Advanced Simulation (IAS-5), Forschungszentrum Jülich GmbH, D-52425, Jülich, Germany
- Institute of Neuroscience and Medicine (INM-9), Forschungszentrum Jülich GmbH, D-52425, Jülich, Germany
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27
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Bafunno V, Bury L, Tiscia GL, Fierro T, Favuzzi G, Caliandro R, Sessa F, Grandone E, Margaglione M, Gresele P. A novel congenital dysprothrombinemia leading to defective prothrombin maturation. Thromb Res 2014; 134:1135-41. [PMID: 25242243 DOI: 10.1016/j.thromres.2014.08.028] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Revised: 07/14/2014] [Accepted: 08/27/2014] [Indexed: 12/22/2022]
Abstract
INTRODUCTION Prothrombin deficiency is a very rare disorder caused by mutations in the F2 gene that generate hypoprothrombinemia or dysprothrombinemia and is characterized by bleeding manifestations that can vary from clinically irrelevant to life-threatening. AIM Here we characterize a patient with a novel missense mutation in F2, c.1090T/A (p.Val322Glu), that causes severe dysprothrombinemia. METHODS Coagulation assays, prothrombin Western Blotting, FII activation by Ecarin, fibrinogen degradation products quantification and thrombin generation assay were carried out to assess prothrombin expression and function. PCR followed by direct sequencing was carried out to characterize the mutation. In silico analysis for missense variant and molecular modeling were applied to predict the mechanism that leads to dysprothrombinemia. RESULTS AND CONCLUSIONS The homozygous patient had a markedly prolonged prothrombin time, strongly reduced FII activity (0.82%) but normal antigen levels. In the thrombin generation assay the lag time and the peak height were unmeasurable, suggesting that the Val322Glu mutation results in the inability of the mutant prothrombin to be fully activated to thrombin. In fact, prothrombin activation by ecarin was defective, with a massive accumulation of the meizothrombin intermediate. Molecular modeling and dynamic simulation studies showed that the Val322Glu mutation interferes with protein flexibility at Arg271 and Arg320. This impairs the switch of the protein from zymogen to proteinase, thus preventing the formation of thrombin. Accumulated meizothrombin, however, maintains some fibrinogen-degrading activity, as shown by the formation of FDPs, and this probably explains the patient's mild bleeding phenotype.
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Affiliation(s)
- Valeria Bafunno
- Medical Genetics, Department of Clinical and Experimental Medicine, University of Foggia, Foggia, Italy
| | - Loredana Bury
- Department of Medicine, Section of Internal and Cardiovascular Medicine, University of Perugia, Perugia, Italy
| | - Giovanni Luca Tiscia
- Atherosclerosis and Thrombosis Unit, Research Department, Istituto di Ricovero e Cura a Carattere Scientifico, Casa Sollievo della Sofferenza, S. Giovanni Rotondo, Foggia, Italy
| | - Tiziana Fierro
- Department of Medicine, Section of Internal and Cardiovascular Medicine, University of Perugia, Perugia, Italy
| | - Giovanni Favuzzi
- Atherosclerosis and Thrombosis Unit, Research Department, Istituto di Ricovero e Cura a Carattere Scientifico, Casa Sollievo della Sofferenza, S. Giovanni Rotondo, Foggia, Italy
| | - Rocco Caliandro
- Institute of Crystallography, Consiglio Nazionale delle Ricerche, Bari, Italy
| | - Francesco Sessa
- Medical Genetics, Department of Clinical and Experimental Medicine, University of Foggia, Foggia, Italy
| | - Elvira Grandone
- Atherosclerosis and Thrombosis Unit, Research Department, Istituto di Ricovero e Cura a Carattere Scientifico, Casa Sollievo della Sofferenza, S. Giovanni Rotondo, Foggia, Italy
| | - Maurizio Margaglione
- Medical Genetics, Department of Clinical and Experimental Medicine, University of Foggia, Foggia, Italy
| | - Paolo Gresele
- Department of Medicine, Section of Internal and Cardiovascular Medicine, University of Perugia, Perugia, Italy.
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28
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Abriata LA, Vila AJ, Dal Peraro M. Molecular dynamics simulations of apocupredoxins: insights into the formation and stabilization of copper sites under entatic control. J Biol Inorg Chem 2014; 19:565-75. [PMID: 24477946 DOI: 10.1007/s00775-014-1108-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2013] [Accepted: 12/30/2013] [Indexed: 10/25/2022]
Abstract
Cupredoxins perform copper-mediated long-range electron transfer (ET) in biological systems. Their copper-binding sites have evolved to force copper ions into ET-competent systems with decreased reorganization energy, increased reduction potential, and a distinct electronic structure compared with those of non-ET-competent copper complexes. The entatic or rack-induced state hypothesis explains these special properties in terms of the strain that the protein matrix exerts on the metal ions. This idea is supported by X-ray structures of apocupredoxins displaying "closed" arrangements of the copper ligands like those observed in the holoproteins; however, it implies completely buried copper-binding atoms, conflicting with the notion that they must be exposed for copper loading. On the other hand, a recent work based on NMR showed that the copper-binding regions of apocupredoxins are flexible in solution. We have explored five cupredoxins in their "closed" apo forms through molecular dynamics simulations. We observed that prearranged ligand conformations are not stable as the X-ray data suggest, although they do form part of the dynamic landscape of the apoproteins. This translates into variable flexibility of the copper-binding regions within a rigid fold, accompanied by fluctuations of the hydrogen bonds around the copper ligands. Major conformations with solvent-exposed copper-binding atoms could allow initial binding of the copper ions. An eventual subsequent incursion to the closed state would result in binding of the remaining ligands, trapping the closed conformation thanks to the additional binding energy and the fastening of noncovalent interactions that make up the rack.
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Affiliation(s)
- Luciano A Abriata
- Laboratory of Biomolecular Modeling, School of Life Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland,
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29
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Cong X, Casiraghi N, Rossetti G, Mohanty S, Giachin G, Legname G, Carloni P. Role of Prion Disease-Linked Mutations in the Intrinsically Disordered N-Terminal Domain of the Prion Protein. J Chem Theory Comput 2013; 9:5158-67. [DOI: 10.1021/ct400534k] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Xiaojing Cong
- Laboratory
of Prion Biology, Department of Neuroscience, Scuola Internazionale Superiore di Studi Avanzati (SISSA), via Bonomea 265, 34136 Trieste, Italy
- Laboratory
for Computational Biophysics, German Research School for Simulation Sciences (GRS), Forschungszentrum Jülich−RWTH Aachen, 52425 Jülich, Germany
- Computational
Biomedicine Section (IAS-5), Institute of Advanced Simulation (IAS), 52425 Jülich, Germany
| | - Nicola Casiraghi
- Laboratory
for Computational Biophysics, German Research School for Simulation Sciences (GRS), Forschungszentrum Jülich−RWTH Aachen, 52425 Jülich, Germany
- Department
of Biology, University of Bologna, via Selmi 3, 40126 Bologna, Italy
- Computational
Biomedicine Section (IAS-5), Institute of Advanced Simulation (IAS), 52425 Jülich, Germany
| | - Giulia Rossetti
- Laboratory
for Computational Biophysics, German Research School for Simulation Sciences (GRS), Forschungszentrum Jülich−RWTH Aachen, 52425 Jülich, Germany
- Jülich Supercomputing Centre, Forschungszentrum Jülich, 52425 Jülich, Germany
- Computational
Biomedicine Section (IAS-5), Institute of Advanced Simulation (IAS), 52425 Jülich, Germany
- Institute for Research in Biomedicine and Barcelona Supercomputing Center Joint Research Program on Computational Biology, Barcelona Science Park, Baldiri I Reixac 10, 08028 Barcelona, Spain
| | - Sandipan Mohanty
- Jülich Supercomputing Centre, Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Gabriele Giachin
- Laboratory
of Prion Biology, Department of Neuroscience, Scuola Internazionale Superiore di Studi Avanzati (SISSA), via Bonomea 265, 34136 Trieste, Italy
| | - Giuseppe Legname
- Laboratory
of Prion Biology, Department of Neuroscience, Scuola Internazionale Superiore di Studi Avanzati (SISSA), via Bonomea 265, 34136 Trieste, Italy
- ELETTRA Laboratory, Sincrotrone
Trieste S.C.p.A., 34149 Basovizza, Trieste, Italy
| | - Paolo Carloni
- Laboratory
for Computational Biophysics, German Research School for Simulation Sciences (GRS), Forschungszentrum Jülich−RWTH Aachen, 52425 Jülich, Germany
- Computational
Biomedicine Section (IAS-5), Institute of Advanced Simulation (IAS), 52425 Jülich, Germany
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30
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Dibenedetto D, Rossetti G, Caliandro R, Carloni P. A Molecular Dynamics Simulation-Based Interpretation of Nuclear Magnetic Resonance Multidimensional Heteronuclear Spectra of α-Synuclein·Dopamine Adducts. Biochemistry 2013; 52:6672-83. [DOI: 10.1021/bi400367r] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Domenica Dibenedetto
- Computational Biophysics,
German Research School for Simulation Sciences (joint
venture of RWTH Aachen University and Forschungszentrum Jülich), D-52425 Jülich, Germany, and Institute for Advanced Simulation IAS-5, Computational
Biomedicine, Forschungszentrum Jülich, D-52425 Jülich, Germany
| | - Giulia Rossetti
- Computational Biophysics,
German Research School for Simulation Sciences (joint
venture of RWTH Aachen University and Forschungszentrum Jülich), D-52425 Jülich, Germany, and Institute for Advanced Simulation IAS-5, Computational
Biomedicine, Forschungszentrum Jülich, D-52425 Jülich, Germany
- Institute for Research in Biomedicine (IRB Barcelona), Baldiri Reixac 10, Barcelona 08028, Spain
- Joint IRB-BSC Program in Computational Biology, Barcelona, Spain
- John
von Neumann Institute for Computing (JSC), Forschungszentrum Jülich, Jülich, Germany
| | - Rocco Caliandro
- Institute
of Crystallography (IC), National Research Council of Italy (CNR), via Amendola, 122/o, 70126 Bari, Italy
| | - Paolo Carloni
- Computational Biophysics,
German Research School for Simulation Sciences (joint
venture of RWTH Aachen University and Forschungszentrum Jülich), D-52425 Jülich, Germany, and Institute for Advanced Simulation IAS-5, Computational
Biomedicine, Forschungszentrum Jülich, D-52425 Jülich, Germany
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31
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Musiani F, Ippoliti E, Micheletti C, Carloni P, Ciurli S. Conformational fluctuations of UreG, an intrinsically disordered enzyme. Biochemistry 2013; 52:2949-54. [PMID: 23560717 DOI: 10.1021/bi4001744] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
UreG proteins are small GTP binding (G) proteins that catalyze the hydrolysis of GTP necessary for the maturation of urease, a virulence factor in bacterial pathogenesis. UreG proteins are the first documented cases of intrinsically disordered enzymes. The comprehension of the dynamics of folding-unfolding events occurring in this protein could shed light on the enzymatic mechanism of UreG. Here, we used the recently developed replica exchange with solute tempering (REST2) computational methodology to explore the conformational space of UreG from Helicobacter pylori (HpUreG) and to identify its structural fluctuations. The same simulation and analysis protocol has been applied to HypB from Methanocaldococcus jannaschii (MjHypB), which is closely related to UreG in both sequence and function, even though it is not intrinsically disordered. A comparison of the two systems reveals that both HpUreG and MjHypB feature a substantial rigidity of the protein regions involved in catalysis, justifying its residual catalytic activity. On the other hand, HpUreG tends to unfold more than MjHypB in portions involved in protein-protein interactions with metallochaperones necessary for the formation of multiprotein complexes known to be involved in urease activation.
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Affiliation(s)
- Francesco Musiani
- Laboratory of Bioinorganic Chemistry, Department of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy
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