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Parise A, Cresca S, Magistrato A. Molecular dynamics simulations for the structure-based drug design: targeting small-GTPases proteins. Expert Opin Drug Discov 2024; 19:1259-1279. [PMID: 39105536 DOI: 10.1080/17460441.2024.2387856] [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: 04/18/2024] [Accepted: 07/30/2024] [Indexed: 08/07/2024]
Abstract
INTRODUCTION Molecular Dynamics (MD) simulations can support mechanism-based drug design. Indeed, MD simulations by capturing biomolecule motions at finite temperatures can reveal hidden binding sites, accurately predict drug-binding poses, and estimate the thermodynamics and kinetics, crucial information for drug discovery campaigns. Small-Guanosine Triphosphate Phosphohydrolases (GTPases) regulate a cascade of signaling events, that affect most cellular processes. Their deregulation is linked to several diseases, making them appealing drug targets. The broad roles of small-GTPases in cellular processes and the recent approval of a covalent KRas inhibitor as an anticancer agent renewed the interest in targeting small-GTPase with small molecules. AREA COVERED This review emphasizes the role of MD simulations in elucidating small-GTPase mechanisms, assessing the impact of cancer-related variants, and discovering novel inhibitors. EXPERT OPINION The application of MD simulations to small-GTPases exemplifies the role of MD simulations in the structure-based drug design process for challenging biomolecular targets. Furthermore, AI and machine learning-enhanced MD simulations, coupled with the upcoming power of quantum computing, are promising instruments to target elusive small-GTPases mutations and splice variants. This powerful synergy will aid in developing innovative therapeutic strategies associated to small-GTPases deregulation, which could potentially be used for personalized therapies and in a tissue-agnostic manner to treat tumors with mutations in small-GTPases.
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Affiliation(s)
- Angela Parise
- Consiglio Nazionale delle Ricerche (CNR) - Istituto Officina dei Materiali (IOM), c/o International School for Advanced Studies (SISSA), Trieste, Italy
| | - Sofia Cresca
- Consiglio Nazionale delle Ricerche (CNR) - Istituto Officina dei Materiali (IOM), c/o International School for Advanced Studies (SISSA), Trieste, Italy
| | - Alessandra Magistrato
- Consiglio Nazionale delle Ricerche (CNR) - Istituto Officina dei Materiali (IOM), c/o International School for Advanced Studies (SISSA), Trieste, Italy
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2
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Hu F, Wang Y, Zeng J, Deng X, Xia F, Xu X. Unveiling the State Transition Mechanisms of Ras Proteins through Enhanced Sampling and QM/MM Simulations. J Phys Chem B 2024; 128:1418-1427. [PMID: 38323538 DOI: 10.1021/acs.jpcb.3c07666] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2024]
Abstract
In cells, wild-type RasGTP complexes exist in two distinct states: active State 2 and inactive State 1. These complexes regulate their functions by transitioning between the two states. However, the mechanisms underlying this state transition have not been clearly elucidated. To address this, we conducted a detailed simulation study to characterize the energetics of the stable states involved in the state transitions of the HRasGTP complex, specifically from State 2 to State 1. This was achieved by employing multiscale quantum mechanics/molecular mechanics and enhanced sampling molecular dynamics methods. Based on the simulation results, we constructed the two-dimensional free energy landscapes that provide crucial information about the conformational changes of the HRasGTP complex from State 2 to State 1. Furthermore, we also explored the conformational changes from the intermediate state to the product state during guanosine triphosphate hydrolysis. This study on the conformational changes involved in the HRas state transitions serves as a valuable reference for understanding the corresponding events of both KRas and NRas as well.
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Affiliation(s)
- Fangchen Hu
- School of Chemistry and Molecular Engineering, East China Normal University, Shanghai 200062, China
| | - Yiqiu Wang
- School of Chemistry and Molecular Engineering, East China Normal University, Shanghai 200062, China
| | - Juan Zeng
- School of Biomedical Engineering, Guangdong Medical University, Dongguan 523808, China
| | - Xianming Deng
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Fei Xia
- School of Chemistry and Molecular Engineering, East China Normal University, Shanghai 200062, China
| | - Xin Xu
- Collaborative Innovation Center of Chemistry for Energy Materials, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, MOE Key Laboratory of Computational Physical Sciences, Department of Chemistry, Fudan University, Shanghai 200433, China
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3
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Baumann P, Jin Y. Far-reaching effects of tyrosine64 phosphorylation on Ras revealed with BeF 3- complexes. Commun Chem 2024; 7:19. [PMID: 38297137 PMCID: PMC10830474 DOI: 10.1038/s42004-024-01105-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 01/11/2024] [Indexed: 02/02/2024] Open
Abstract
Tyrosine phosphorylation on Ras by Src kinase is known to uncouple Ras from upstream regulation and downstream communication. However, the mechanisms by which phosphorylation modulates these interactions have not been detailed. Here, the major mono-phosphorylation level on tyrosine64 is quantified by 31P NMR and mutagenesis. Crystal structures of unphosphorylated and tyrosine64-phosphorylated Ras in complex with a BeF3- ground state analogue reveal "closed" Ras conformations very different from those of the "open" conformations previously observed for non-hydrolysable GTP analogue structures of Ras. They deliver new mechanistic and conformational insights into intrinsic GTP hydrolysis. Phosphorylation of tyrosine64 delivers conformational changes distant from the active site, showing why phosphorylated Ras has reduced affinity to its downstream effector Raf. 19F NMR provides evidence for changes in the intrinsic GTPase and nucleotide exchange rate and identifies the concurrent presence of a major "closed" conformation alongside a minor yet functionally important "open" conformation at the ground state of Ras. This study expands the application of metal fluoride complexes in revealing major and minor conformational changes of dynamic and modified Ras proteins.
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Affiliation(s)
- Patrick Baumann
- School of Chemistry, Cardiff University, Park Place, Cardiff, CF10 3AT, UK
- Department of Chemistry, School of Natural Sciences, Faculty of Science and Engineering, University of Manchester, M13 9PL, Manchester, UK
- Manchester Institute of Biotechnology, University of Manchester, 131 Princess Street, Manchester, M1 7DN, UK
| | - Yi Jin
- School of Chemistry, Cardiff University, Park Place, Cardiff, CF10 3AT, UK.
- Department of Chemistry, School of Natural Sciences, Faculty of Science and Engineering, University of Manchester, M13 9PL, Manchester, UK.
- Manchester Institute of Biotechnology, University of Manchester, 131 Princess Street, Manchester, M1 7DN, UK.
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4
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Kou X, Cao P, Zhao Z, Zhang X, Dai Y, Wang K, Wu J, Zhang S. Comparative genomic analysis of the RabGAP gene family in seven Rosaceae species, and functional identification of PbrRabGAP10 in controlling pollen tube growth by mediating cellulose deposition in pear. Int J Biol Macromol 2024; 256:128498. [PMID: 38042315 DOI: 10.1016/j.ijbiomac.2023.128498] [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: 08/12/2023] [Revised: 11/26/2023] [Accepted: 11/27/2023] [Indexed: 12/04/2023]
Abstract
Rab GTPase-activating proteins (RabGAPs), serving as crucial signaling switches, play essential roles in several physiological processes related to plant growth and development. However, despite their importance, information regarding the RabGAP gene family and their biological functions remains unknown in the Rosaceae. In this study, we identified a total of 127 RabGAP genes in seven Rosaceae species, which were divided into five subfamilies. Our findings indicate that whole genome duplication (WGD) events or dispersed duplication events largely contributed to the expansion of RabGAP family members within Rosaceae species. Through tissue-specific expression analyses, we revealed that the PbrRabGAP genes exhibited distinct expression patterns in different pear tissues. Furthermore, by examining the expression pattern during pollen development and employing an antisense oligonucleotide approach, we demonstrated that PbrRabGAP10, located in the cytoplasm, mediates the imbalance of cellulose distribution, thus regulating pollen tube elongation. In conclusion, the present study offers an overview of the RabGAP family in Rosaceae genomes and serves as the basis for further functional studies.
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Affiliation(s)
- Xiaobing Kou
- School of Life Sciences, Nantong University, Nantong 226019, Jiangsu, People's Republic of China.
| | - Peng Cao
- College of Faculty of Applied Technology, Huaiyin Institute of Technology, Huai'an 223003, China
| | - Zhen Zhao
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China
| | - Xin Zhang
- School of Life Sciences, Nantong University, Nantong 226019, Jiangsu, People's Republic of China
| | - Yan Dai
- School of Life Sciences, Nantong University, Nantong 226019, Jiangsu, People's Republic of China
| | - Kai Wang
- School of Life Sciences, Nantong University, Nantong 226019, Jiangsu, People's Republic of China
| | - Juyou Wu
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China
| | - Shaoling Zhang
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China.
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5
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Berta D, Gehrke S, Nyíri K, Vértessy BG, Rosta E. Mechanism-Based Redesign of GAP to Activate Oncogenic Ras. J Am Chem Soc 2023; 145:20302-20310. [PMID: 37682266 PMCID: PMC10515638 DOI: 10.1021/jacs.3c04330] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Indexed: 09/09/2023]
Abstract
Ras GTPases play a crucial role in cell signaling pathways. Mutations of the Ras gene occur in about one third of cancerous cell lines and are often associated with detrimental clinical prognosis. Hot spot residues Gly12, Gly13, and Gln61 cover 97% of oncogenic mutations, which impair the enzymatic activity in Ras. Using QM/MM free energy calculations, we present a two-step mechanism for the GTP hydrolysis catalyzed by the wild-type Ras.GAP complex. We found that the deprotonation of the catalytic water takes place via the Gln61 as a transient Brønsted base. We also determined the reaction profiles for key oncogenic Ras mutants G12D and G12C using QM/MM minimizations, matching the experimentally observed loss of catalytic activity, thereby validating our reaction mechanism. Using the optimized reaction paths, we devised a fast and accurate procedure to design GAP mutants that activate G12D Ras. We replaced GAP residues near the active site and determined the activation barrier for 190 single mutants. We furthermore built a machine learning for ultrafast screening, by fast prediction of the barrier heights, tested both on the single and double mutations. This work demonstrates that fast and accurate screening can be accomplished via QM/MM reaction path optimizations to design protein sequences with increased catalytic activity. Several GAP mutations are predicted to re-enable catalysis in oncogenic G12D, offering a promising avenue to overcome aberrant Ras-driven signal transduction by activating enzymatic activity instead of inhibition. The outlined computational screening protocol is readily applicable for designing ligands and cofactors analogously.
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Affiliation(s)
- Dénes Berta
- Department
of Physics and Astronomy, University College
London, Gower Street, London WC1E
6BT, United Kingdom
| | - Sascha Gehrke
- Department
of Physics and Astronomy, University College
London, Gower Street, London WC1E
6BT, United Kingdom
| | - Kinga Nyíri
- Institute
of Enzymology, Research Centre for Natural Sciences, Magyar tudósok körútja
2, Budapest 1117, Hungary
- Department
of Applied Biotechnology and Food Science, Budapest University of Technology and Economics, Budafoki út 6-8, Budapest 1111, Hungary
| | - Beáta G. Vértessy
- Institute
of Enzymology, Research Centre for Natural Sciences, Magyar tudósok körútja
2, Budapest 1117, Hungary
- Department
of Applied Biotechnology and Food Science, Budapest University of Technology and Economics, Budafoki út 6-8, Budapest 1111, Hungary
| | - Edina Rosta
- Department
of Physics and Astronomy, University College
London, Gower Street, London WC1E
6BT, United Kingdom
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6
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Shanbhag C, Saraogi I. Bacterial GTPases as druggable targets to tackle antimicrobial resistance. Bioorg Med Chem Lett 2023; 87:129276. [PMID: 37030567 DOI: 10.1016/j.bmcl.2023.129276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 04/03/2023] [Accepted: 04/04/2023] [Indexed: 04/08/2023]
Abstract
Small molecules as antibacterial agents have contributed immensely to the growth of modern medicine over the last several decades. However, the emergence of drug resistance among bacterial pathogens has undermined the effectiveness of the existing antibiotics. Thus, there is an exigency to address the antibiotic crisis by developing new antibacterial agents and identifying novel drug targets in bacteria. In this review, we summarize the importance of guanosine triphosphate hydrolyzing proteins (GTPases) as key agents for bacterial survival. We also discuss representative examples of small molecules that target bacterial GTPases as novel antibacterial agents, and highlight areas that are ripe for exploration. Given their vital roles in cell viability, virulence, and antibiotic resistance, bacterial GTPases are highly attractive antibacterial targets that will likely play a vital role in the fight against antimicrobial resistance.
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7
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Zhu Y, Zhang H, Jiang P, Xie C, Luo Y, Chen J. Transcriptional and Epigenetic Alterations in the Progression of Non-Alcoholic Fatty Liver Disease and Biomarkers Helping to Diagnose Non-Alcoholic Steatohepatitis. Biomedicines 2023; 11:biomedicines11030970. [PMID: 36979950 PMCID: PMC10046227 DOI: 10.3390/biomedicines11030970] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2023] [Revised: 03/12/2023] [Accepted: 03/17/2023] [Indexed: 03/30/2023] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD) encompasses a broad spectrum of conditions from simple steatosis (non-alcoholic fatty liver (NAFL)) to non-alcoholic steatohepatitis (NASH), and its global prevalence continues to rise. NASH, the progressive form of NAFLD, has higher risks of liver and non-liver related adverse outcomes compared with those patients with NAFL alone. Therefore, the present study aimed to explore the mechanisms in the progression of NAFLD and to develop a model to diagnose NASH based on the transcriptome and epigenome. Differentially expressed genes (DEGs) and differentially methylated genes (DMGs) among the three groups (normal, NAFL, and NASH) were identified, and the functional analysis revealed that the development of NAFLD was primarily related to the oxidoreductase-related activity, PPAR signaling pathway, tight junction, and pathogenic Escherichia coli infection. The logistic regression (LR) model, consisting of ApoF, THOP1, and BICC1, outperformed the other five models. With the highest AUC (0.8819, 95%CI: 0.8128-0.9511) and a sensitivity of 97.87%, as well as a specificity of 64.71%, the LR model was determined as the diagnostic model, which can differentiate NASH from NAFL. In conclusion, several potential mechanisms were screened out based on the transcriptome and epigenome, and a diagnostic model was built to help patient stratification for NAFLD populations.
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Affiliation(s)
- Yalan Zhu
- Department of Laboratory Medicine, West China Hospital, Sichuan University, Chengdu 610041, China
| | - He Zhang
- Department of Laboratory Medicine, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Pengjun Jiang
- Department of Laboratory Medicine, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Chengxia Xie
- Department of Laboratory Medicine, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Yao Luo
- Department of Laboratory Medicine, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Jie Chen
- Department of Laboratory Medicine, West China Hospital, Sichuan University, Chengdu 610041, China
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8
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Grupp B, Gronemeyer T. A biochemical view on the septins, a less known component of the cytoskeleton. Biol Chem 2023; 404:1-13. [PMID: 36423333 DOI: 10.1515/hsz-2022-0263] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Accepted: 10/30/2022] [Indexed: 11/25/2022]
Abstract
The septins are a conserved family of guanine nucleotide binding proteins, often named the fourth component of the cytoskeleton. They self-assemble into non-polar filaments and further into higher ordered structures. Properly assembled septin structures are required for a wide range of indispensable intracellular processes such as cytokinesis, vesicular transport, polarity establishment and cellular adhesion. Septins belong structurally to the P-Loop NTPases. However, unlike the small GTPases like Ras, septins do not mediate signals to effectors through GTP binding and hydrolysis. The role of nucleotide binding and subsequent GTP hydrolysis by the septins is rather controversially debated. We compile here the structural features from the existing septin crystal- and cryo-EM structures regarding protofilament formation, inter-subunit interface architecture and nucleotide binding and hydrolysis. These findings are supplemented with a summary of available biochemical studies providing information regarding nucleotide binding and hydrolysis of fungal and mammalian septins.
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Affiliation(s)
- Benjamin Grupp
- Institute of Molecular Genetics and Cell Biology, Ulm University, James Franck Ring N27, 89081 Ulm, Germany
| | - Thomas Gronemeyer
- Institute of Molecular Genetics and Cell Biology, Ulm University, James Franck Ring N27, 89081 Ulm, Germany
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9
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Vaccaro FA, Drennan CL. The role of nucleoside triphosphate hydrolase metallochaperones in making metalloenzymes. Metallomics 2022; 14:6575898. [PMID: 35485745 PMCID: PMC9164220 DOI: 10.1093/mtomcs/mfac030] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Accepted: 04/07/2022] [Indexed: 11/13/2022]
Abstract
Metalloenzymes catalyze a diverse set of challenging chemical reactions that are essential for life. These metalloenzymes rely on a wide range of metallocofactors, from single metal ions to complicated metallic clusters. Incorporation of metal ions and metallocofactors into apo-proteins often requires the assistance of proteins known as metallochaperones. Nucleoside triphosphate hydrolases (NTPases) are one important class of metallochaperones and are found widely distributed throughout the domains of life. These proteins use the binding and hydrolysis of nucleoside triphosphates, either adenosine triphosphate (ATP) or guanosine triphosphate (GTP), to carry out highly specific and regulated roles in the process of metalloenzyme maturation. Here, we review recent literature on NTPase metallochaperones and describe the current mechanistic proposals and available structural data. By using representative examples from each type of NTPase, we also illustrate the challenges in studying these complicated systems. We highlight open questions in the field and suggest future directions. This minireview is part of a special collection of articles in memory of Professor Deborah Zamble, a leader in the field of nickel biochemistry.
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Affiliation(s)
- Francesca A Vaccaro
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, USA
| | - Catherine L Drennan
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, USA.,Department of Biology, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, USA.,Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA, USA
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10
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Khrenova MG, Grigorenko BL, Nemukhin AV. Molecular Modeling Reveals the Mechanism of Ran-RanGAP-Catalyzed Guanosine Triphosphate Hydrolysis without an Arginine Finger. ACS Catal 2021. [DOI: 10.1021/acscatal.1c00582] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Maria G. Khrenova
- Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory 1/3, Moscow 119991, Russia
- Bach Institute of Biochemistry, Federal Research Centre “Fundamentals of Biotechnology”, Russian Academy of Sciences, Moscow 119071, Russia
| | - Bella L. Grigorenko
- Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory 1/3, Moscow 119991, Russia
- Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, Moscow 19334, Russia
| | - Alexander V. Nemukhin
- Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory 1/3, Moscow 119991, Russia
- Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, Moscow 19334, Russia
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11
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Khrenova MG, Bulavko ES, Mulashkin FD, Nemukhin AV. Mechanism of Guanosine Triphosphate Hydrolysis by the Visual Proteins Arl3-RP2: Free Energy Reaction Profiles Computed with Ab Initio Type QM/MM Potentials. Molecules 2021; 26:3998. [PMID: 34208932 PMCID: PMC8271468 DOI: 10.3390/molecules26133998] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 06/27/2021] [Accepted: 06/28/2021] [Indexed: 11/23/2022] Open
Abstract
We report the results of calculations of the Gibbs energy profiles of the guanosine triphosphate (GTP) hydrolysis by the Arl3-RP2 protein complex using molecular dynamics (MD) simulations with ab initio type QM/MM potentials. The chemical reaction of GTP hydrolysis to guanosine diphosphate (GDP) and inorganic phosphate (Pi) is catalyzed by GTPases, the enzymes, which are responsible for signal transduction in live cells. A small GTPase Arl3, catalyzing the GTP → GDP reaction in complex with the activating protein RP2, constitute an essential part of the human vision cycle. To simulate the reaction mechanism, a model system is constructed by motifs of the crystal structure of the Arl3-RP2 complexed with a substrate analog. After selection of reaction coordinates, energy profiles for elementary steps along the reaction pathway GTP + H2O → GDP + Pi are computed using the umbrella sampling and umbrella integration procedures. QM/MM MD calculations are carried out, interfacing the molecular dynamics program NAMD and the quantum chemistry program TeraChem. Ab initio type QM(DFT)/MM potentials are computed with atom-centered basis sets 6-31G** and two hybrid functionals (PBE0-D3 and ωB97x-D3) of the density functional theory, describing a large QM subsystem. Results of these simulations of the reaction mechanism are compared to those obtained with QM/MM calculations on the potential energy surface using a similar description of the QM part. We find that both approaches, QM/MM and QM/MM MD, support the mechanism of GTP hydrolysis by GTPases, according to which the catalytic glutamine side chain (Gln71, in this system) actively participates in the reaction. Both approaches distinguish two parts of the reaction: the cleavage of the phosphorus-oxygen bond in GTP coupled with the formation of Pi, and the enzyme regeneration. Newly performed QM/MM MD simulations confirmed the profile predicted in the QM/MM minimum energy calculations, called here the pathway-I, and corrected its relief at the first elementary step from the enzyme-substrate complex. The QM/MM MD simulations also revealed another mechanism at the part of enzyme regeneration leading to pathway-II. Pathway-II is more consistent with the experimental kinetic data of the wild-type complex Arl3-RP2, whereas pathway-I explains the role of the mutation Glu138Gly in RP2 slowing down the hydrolysis rate.
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Affiliation(s)
- Maria G. Khrenova
- Chemistry Department, M.V. Lomonosov Moscow State University, Leninskie Gory 1/3, 119991 Moscow, Russia; (M.G.K.); (F.D.M.)
- Bach Institute of Biochemistry, Federal Research Centre “Fundamentals of Biotechnology” of the Russian Academy of Sciences, 119071 Moscow, Russia
| | - Egor S. Bulavko
- Biology Department, M.V. Lomonosov Moscow State University, Leninskie Gory 1/3, 119991 Moscow, Russia;
| | - Fedor D. Mulashkin
- Chemistry Department, M.V. Lomonosov Moscow State University, Leninskie Gory 1/3, 119991 Moscow, Russia; (M.G.K.); (F.D.M.)
| | - Alexander V. Nemukhin
- Chemistry Department, M.V. Lomonosov Moscow State University, Leninskie Gory 1/3, 119991 Moscow, Russia; (M.G.K.); (F.D.M.)
- N.M. Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, Kosygina 4, 119334 Moscow, Russia
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12
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López CA, Agarwal A, Van QN, Stephen AG, Gnanakaran S. Unveiling the Dynamics of KRAS4b on Lipid Model Membranes. J Membr Biol 2021; 254:201-216. [PMID: 33825026 PMCID: PMC8052243 DOI: 10.1007/s00232-021-00176-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Accepted: 03/16/2021] [Indexed: 12/23/2022]
Abstract
Small GTPase proteins are ubiquitous and responsible for regulating several processes related to cell growth and differentiation. Mutations that stabilize their active state can lead to uncontrolled cell proliferation and cancer. Although these proteins are well characterized at the cellular scale, the molecular mechanisms governing their functions are still poorly understood. In addition, there is limited information about the regulatory function of the cell membrane which supports their activity. Thus, we have studied the dynamics and conformations of the farnesylated KRAS4b in various membrane model systems, ranging from binary fluid mixtures to heterogeneous raft mimics. Our approach combines long time-scale coarse-grained (CG) simulations and Markov state models to dissect the membrane-supported dynamics of KRAS4b. Our simulations reveal that protein dynamics is mainly modulated by the presence of anionic lipids and to some extent by the nucleotide state (activation) of the protein. In addition, our results suggest that both the farnesyl and the polybasic hypervariable region (HVR) are responsible for its preferential partitioning within the liquid-disordered (Ld) domains in membranes, potentially enhancing the formation of membrane-driven signaling platforms.
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Affiliation(s)
- Cesar A López
- Theoretical Biology and Biophysics Group, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA.
| | - Animesh Agarwal
- Theoretical Biology and Biophysics Group, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
| | - Que N Van
- National Cancer Institute RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc., Frederick, MD, 21702, USA
| | - Andrew G Stephen
- National Cancer Institute RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc., Frederick, MD, 21702, USA
| | - S Gnanakaran
- Theoretical Biology and Biophysics Group, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
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13
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Grigorenko BL, Nemukhin AV. Theoretical Vibrational Spectra of Reaction Intermediates in the Active Site of Guanosine Triphosphate Binding Proteins. RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY A 2020. [DOI: 10.1134/s0036024420050088] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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14
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Calixto AR, Moreira C, Kamerlin SCL. Recent Advances in Understanding Biological GTP Hydrolysis through Molecular Simulation. ACS OMEGA 2020; 5:4380-4385. [PMID: 32175485 PMCID: PMC7066566 DOI: 10.1021/acsomega.0c00240] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Accepted: 02/18/2020] [Indexed: 05/04/2023]
Abstract
GTP hydrolysis is central to biology, being involved in regulating a wide range of cellular processes. However, the mechanisms by which GTPases hydrolyze this critical reaction remain controversial, with multiple mechanistic possibilities having been proposed based on analysis of experimental and computational data. In this mini-review, we discuss advances in our understanding of biological GTP hydrolysis based on recent computational studies and argue in favor of solvent-assisted hydrolysis as a conserved mechanism among GTPases. A concrete understanding of the fundamental mechanisms by which these enzymes facilitate GTP hydrolysis will have significant impact both for drug discovery efforts and for unraveling the role of oncogenic mutations.
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Affiliation(s)
- Ana Rita Calixto
- Department of Chemistry - BMC, Uppsala University, BMC Box 576, S-751 23 Uppsala, Sweden
| | - Cátia Moreira
- Department of Chemistry - BMC, Uppsala University, BMC Box 576, S-751 23 Uppsala, Sweden
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15
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Grigorenko BL, Kots ED, Nemukhin AV. Diversity of mechanisms in Ras-GAP catalysis of guanosine triphosphate hydrolysis revealed by molecular modeling. Org Biomol Chem 2020; 17:4879-4891. [PMID: 31041977 DOI: 10.1039/c9ob00463g] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The mechanism of the deceptively simple reaction of guanosine triphosphate (GTP) hydrolysis catalyzed by the cellular protein Ras in complex with the activating protein GAP is an important issue because of the significance of this reaction in cancer research. We show that molecular modeling of GTP hydrolysis in the Ras-GAP active site reveals a diversity of mechanisms of the intrinsic chemical reaction depending on molecular groups at position 61 in Ras occupied by glutamine in the wild-type enzyme. First, a comparison of reaction energy profiles computed at the quantum mechanics/molecular mechanics (QM/MM) level shows that an assignment of the Gln61 side chain in the wild-type Ras either to QM or to MM parts leads to different scenarios corresponding to the glutamine-assisted or the substrate-assisted mechanisms. Second, replacement of Gln61 by the nitro-analog of glutamine (NGln) or by Glu, applied in experimental studies, results in two more scenarios featuring the so-called two-water and the concerted-type mechanisms. The glutamine-assisted mechanism in the wild-type Ras-GAP, in which the conserved Gln61 plays a decisive role, switching between the amide and imide tautomer forms, is consistent with the known experimental results of structural, kinetic and spectroscopy studies. The results emphasize the role of the Ras residue Gln61 in Ras-GAP catalysis and explain the retained catalytic activity of the Ras-GAP complex towards GTP hydrolysis in the Gln61NGln and Gln61Glu mutants of Ras.
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Affiliation(s)
- Bella L Grigorenko
- Department of Chemistry, Lomonosov Moscow State University, Moscow, 119991, Russia.
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16
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Bennison DJ, Irving SE, Corrigan RM. The Impact of the Stringent Response on TRAFAC GTPases and Prokaryotic Ribosome Assembly. Cells 2019; 8:cells8111313. [PMID: 31653044 PMCID: PMC6912228 DOI: 10.3390/cells8111313] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 10/17/2019] [Accepted: 10/23/2019] [Indexed: 12/24/2022] Open
Abstract
Many facets of ribosome biogenesis and function, including ribosomal RNA (rRNA) transcription, 70S assembly and protein translation, are negatively impacted upon induction of a nutrient stress-sensing signalling pathway termed the stringent response. This stress response is mediated by the alarmones guanosine tetra- and penta-phosphate ((p)ppGpp), the accumulation of which leads to a massive cellular response that slows growth and aids survival. The 70S bacterial ribosome is an intricate structure, with assembly both complex and highly modular. Presiding over the assembly process is a group of P-loop GTPases within the TRAFAC (Translation Factor Association) superclass that are crucial for correct positioning of both early and late stage ribosomal proteins (r-proteins) onto the rRNA. Often described as 'molecular switches', members of this GTPase superfamily readily bind and hydrolyse GTP to GDP in a cyclic manner that alters the propensity of the GTPase to carry out a function. TRAFAC GTPases are considered to act as checkpoints to ribosome assembly, involved in binding to immature sections in the GTP-bound state, preventing further r-protein association until maturation is complete. Here we review our current understanding of the impact of the stringent response and (p)ppGpp production on ribosome maturation in prokaryotic cells, focusing on the inhibition of (p)ppGpp on GTPase-mediated subunit assembly, but also touching upon the inhibition of rRNA transcription and protein translation.
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Affiliation(s)
- Daniel J Bennison
- The Florey Institute, Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, UK.
| | - Sophie E Irving
- The Florey Institute, Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, UK.
| | - Rebecca M Corrigan
- The Florey Institute, Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, UK.
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17
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Calixto AR, Moreira C, Pabis A, Kötting C, Gerwert K, Rudack T, Kamerlin SCL. GTP Hydrolysis Without an Active Site Base: A Unifying Mechanism for Ras and Related GTPases. J Am Chem Soc 2019; 141:10684-10701. [PMID: 31199130 DOI: 10.1021/jacs.9b03193] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
GTP hydrolysis is a biologically crucial reaction, being involved in regulating almost all cellular processes. As a result, the enzymes that catalyze this reaction are among the most important drug targets. Despite their vital importance and decades of substantial research effort, the fundamental mechanism of enzyme-catalyzed GTP hydrolysis by GTPases remains highly controversial. Specifically, how do these regulatory proteins hydrolyze GTP without an obvious general base in the active site to activate the water molecule for nucleophilic attack? To answer this question, we perform empirical valence bond simulations of GTPase-catalyzed GTP hydrolysis, comparing solvent- and substrate-assisted pathways in three distinct GTPases, Ras, Rab, and the Gαi subunit of a heterotrimeric G-protein, both in the presence and in the absence of the corresponding GTPase activating proteins. Our results demonstrate that a general base is not needed in the active site, as the preferred mechanism for GTP hydrolysis is a conserved solvent-assisted pathway. This pathway involves the rate-limiting nucleophilic attack of a water molecule, leading to a short-lived intermediate that tautomerizes to form H2PO4- and GDP as the final products. Our fundamental biochemical insight into the enzymatic regulation of GTP hydrolysis not only resolves a decades-old mechanistic controversy but also has high relevance for drug discovery efforts. That is, revisiting the role of oncogenic mutants with respect to our mechanistic findings would pave the way for a new starting point to discover drugs for (so far) "undruggable" GTPases like Ras.
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Affiliation(s)
- Ana R Calixto
- Department of Chemistry-BMC , Uppsala University , Box 576, S-751 23 Uppsala , Sweden
| | - Cátia Moreira
- Department of Chemistry-BMC , Uppsala University , Box 576, S-751 23 Uppsala , Sweden
| | - Anna Pabis
- Department of Cell and Molecular Biology , Uppsala University , BMC Box 596, S-751 24 , Uppsala , Sweden
| | - Carsten Kötting
- Department of Biophysics , Ruhr University Bochum , 44801 Bochum , Germany
| | - Klaus Gerwert
- Department of Biophysics , Ruhr University Bochum , 44801 Bochum , Germany
| | - Till Rudack
- Department of Biophysics , Ruhr University Bochum , 44801 Bochum , Germany
| | - Shina C L Kamerlin
- Department of Chemistry-BMC , Uppsala University , Box 576, S-751 23 Uppsala , Sweden
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18
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Tichauer RH, Favre G, Cabantous S, Brut M. Hybrid QM/MM vs Pure MM Molecular Dynamics for Evaluating Water Distribution within p21 N-ras and the Resulting GTP Electronic Density. J Phys Chem B 2019; 123:3935-3944. [PMID: 30991803 DOI: 10.1021/acs.jpcb.9b02660] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
p21ras protein activity, regulated by GTP hydrolysis, constitutes an active field of research for the development of cancer targeted therapies that would concern ∼30% of human tumors to which specific mutations have been associated. Indeed, the catalyzing mechanisms provided by the protein environment during GTP hydrolysis and how they are impaired by specific mutations remain to be fully elucidated. In this article, we present results from molecular mechanics (MM) molecular dynamics (MD) simulations and density functional theory (DFT) calculations carried out for wild-type p21 N-ras and six Gln 61 mutants. In the first part, we present the water distribution within the active site of the wild-type protein according to MM MD. Significant differences are observed when comparing the results to the previous distribution assessed through quantum mechanics/molecular mechanics (QM/MM) MD. Such method-dependent results highlight the importance of accounting for the electrostatic coupling between the protein complex and the solvent molecules in identifying hydration sites. In the second part, we present the results from DFT calculations performed to determine the electronic distribution of the GTP ligand, considering the wild-type active site arrangement according to both classical and hybrid approaches. Only in the QM/MM-based configuration is the ligand electronic density similar to that of a GDP-like state observed experimentally. For this reason, in the last set of calculations carried out for p21 N-ras Gln 61 mutants, only the active site structural conformations obtained through hybrid MD are considered. Through the analysis of the GTP electronic density, we conclude that the wild-type active site arrangement according to QM/MM MD is closer to a catalytically efficient conformation of the protein than the arrangement according to MM MD. Hence, water distribution according to the hybrid approach must correspond to the optimal placement of solvent in the active site. Within all of the studied Gln 61 substituted proteins, p21ras major catalyzing effect, which consists of stabilizing a more GDP-like state, is lost.
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Affiliation(s)
- Ruth H Tichauer
- LAAS-CNRS , Université de Toulouse , CNRS, UPS, Toulouse , France
| | - Gilles Favre
- Cancer Research Center of Toulouse , INSERM U1037, Université de Toulouse , 31037 Toulouse , France
| | - Stéphanie Cabantous
- Cancer Research Center of Toulouse , INSERM U1037, Université de Toulouse , 31037 Toulouse , France
| | - Marie Brut
- LAAS-CNRS , Université de Toulouse , CNRS, UPS, Toulouse , France
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19
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Melatti C, Pieperhoff M, Lemgruber L, Pohl E, Sheiner L, Meissner M. A unique dynamin-related protein is essential for mitochondrial fission in Toxoplasma gondii. PLoS Pathog 2019; 15:e1007512. [PMID: 30947298 PMCID: PMC6448817 DOI: 10.1371/journal.ppat.1007512] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2018] [Accepted: 12/10/2018] [Indexed: 11/19/2022] Open
Abstract
The single mitochondrion of apicomplexan protozoa is thought to be critical for all stages of the life cycle, and is a validated drug target against these important human and veterinary parasites. In contrast to other eukaryotes, replication of the mitochondrion is tightly linked to the cell cycle. A key step in mitochondrial segregation is the fission event, which in many eukaryotes occurs by the action of dynamins constricting the outer membrane of the mitochondria from the cytosolic face. To date, none of the components of the apicomplexan fission machinery have been identified and validated. We identify here a highly divergent, dynamin-related protein (TgDrpC), conserved in apicomplexans as essential for mitochondrial biogenesis and potentially for fission in Toxoplasma gondii. We show that TgDrpC is found adjacent to the mitochondrion, and is localised both at its periphery and at its basal part, where fission is expected to occur. We demonstrate that depletion or dominant negative expression of TgDrpC results in interconnected mitochondria and ultimately in drastic changes in mitochondrial morphology, as well as in parasite death. Intriguingly, we find that the canonical adaptor TgFis1 is not required for mitochondrial fission. The identification of an Apicomplexa-specific enzyme required for mitochondrial biogenesis and essential for parasite growth highlights parasite adaptation. This work paves the way for future drug development targeting TgDrpC, and for the analysis of additional partners involved in this crucial step of apicomplexan multiplication.
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Affiliation(s)
- Carmen Melatti
- Wellcome Trust Centre for Molecular Parasitology, Institute of Infection, Immunity & Inflammation, Glasgow Biomedical Research Centre, University of Glasgow, Glasgow, United Kingdom
| | - Manuela Pieperhoff
- Wellcome Trust Centre for Molecular Parasitology, Institute of Infection, Immunity & Inflammation, Glasgow Biomedical Research Centre, University of Glasgow, Glasgow, United Kingdom
| | - Leandro Lemgruber
- Wellcome Trust Centre for Molecular Parasitology, Institute of Infection, Immunity & Inflammation, Glasgow Biomedical Research Centre, University of Glasgow, Glasgow, United Kingdom
| | - Ehmke Pohl
- Department of Biosciences, & Biophysical Sciences Institute, Durham University, Durham, United Kingdom
| | - Lilach Sheiner
- Wellcome Trust Centre for Molecular Parasitology, Institute of Infection, Immunity & Inflammation, Glasgow Biomedical Research Centre, University of Glasgow, Glasgow, United Kingdom
| | - Markus Meissner
- Wellcome Trust Centre for Molecular Parasitology, Institute of Infection, Immunity & Inflammation, Glasgow Biomedical Research Centre, University of Glasgow, Glasgow, United Kingdom
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20
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Tripathi R, Noetzel J, Marx D. Exposing catalytic versatility of GTPases: taking reaction detours in mutants of hGBP1 enzyme without additional energetic cost. Phys Chem Chem Phys 2019; 21:859-867. [DOI: 10.1039/c8cp06343e] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Our study reveals that the replacement of catalytically competent residues by the inert amino acid alanine, S73A and E99A, in hGBP1 opens a plethora of molecularly different reaction pathways featuring very similar energy barriers as the wild type.
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Affiliation(s)
- Ravi Tripathi
- Lehrstuhl für Theoretische Chemie
- Ruhr-Universität Bochum
- 44780 Bochum
- Germany
| | - Jan Noetzel
- Lehrstuhl für Theoretische Chemie
- Ruhr-Universität Bochum
- 44780 Bochum
- Germany
| | - Dominik Marx
- Lehrstuhl für Theoretische Chemie
- Ruhr-Universität Bochum
- 44780 Bochum
- Germany
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21
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Novelli ET, First JT, Webb LJ. Quantitative Measurement of Intrinsic GTP Hydrolysis for Carcinogenic Glutamine 61 Mutants in H-Ras. Biochemistry 2018; 57:6356-6366. [PMID: 30339365 DOI: 10.1021/acs.biochem.8b00878] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Mutations of human oncoprotein p21H-Ras (hereafter "Ras") at glutamine 61 are known to slow the rate of guanosine triphosphate (GTP) hydrolysis and transform healthy cells into malignant cells. It has been hypothesized that this glutamine plays a role in the intrinsic mechanism of GTP hydrolysis by interacting with an active site water molecule that stabilizes the formation of the charged transition state at the γ-phosphate during hydrolysis. However, there is no comprehensive data set of the effects of mutations to Q61 on the protein's intrinsic catalytic rate, structure, or interactions with water at the active site. Here, we present the first comprehensive and quantitative set of initial rates of intrinsic hydrolysis for all stable variants of RasQ61X. We further conducted enhanced molecular dynamics (MD) simulations of each construct to determine the solvent accessible surface area (SASA) of the side chain at position 61 and compared these results to previously measured changes in electric fields caused by RasQ61X mutations. For polar and negatively charged residues, we found that the rates are normally distributed about an optimal electrostatic contribution, close to that of the native Q61 residue, and the rates are strongly correlated to the number of waters in the active site. Together, these results support a mechanism of GTP hydrolysis in which Q61 stabilizes a transient hydronium ion, which then stabilizes the transition state while the γ-phosphate is undergoing nucleophilic attack by a second, catalytically active water molecule. We discuss the implications of such a mechanism on future strategies for combating Ras-based cancers.
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Affiliation(s)
- Elisa T Novelli
- Department of Chemistry, Texas Materials Institute, Institute for Cell and Molecular Biology , The University of Texas at Austin , 105 E 24th Street STOP A5300 , Austin , Texas 78712-1224 , United States
| | - Jeremy T First
- Department of Chemistry, Texas Materials Institute, Institute for Cell and Molecular Biology , The University of Texas at Austin , 105 E 24th Street STOP A5300 , Austin , Texas 78712-1224 , United States
| | - Lauren J Webb
- Department of Chemistry, Texas Materials Institute, Institute for Cell and Molecular Biology , The University of Texas at Austin , 105 E 24th Street STOP A5300 , Austin , Texas 78712-1224 , United States
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22
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Prieß M, Göddeke H, Groenhof G, Schäfer LV. Molecular Mechanism of ATP Hydrolysis in an ABC Transporter. ACS CENTRAL SCIENCE 2018; 4:1334-1343. [PMID: 30410971 PMCID: PMC6202651 DOI: 10.1021/acscentsci.8b00369] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Indexed: 05/28/2023]
Abstract
Hydrolysis of nucleoside triphosphate (NTP) plays a key role for the function of many biomolecular systems. However, the chemistry of the catalytic reaction in terms of an atomic-level understanding of the structural, dynamic, and free energy changes associated with it often remains unknown. Here, we report the molecular mechanism of adenosine triphosphate (ATP) hydrolysis in the ATP-binding cassette (ABC) transporter BtuCD-F. Free energy profiles obtained from hybrid quantum mechanical/molecular mechanical (QM/MM) molecular dynamics (MD) simulations show that the hydrolysis reaction proceeds in a stepwise manner. First, nucleophilic attack of an activated lytic water molecule at the ATP γ-phosphate yields ADP + HPO4 2- as intermediate product. A conserved glutamate that is located very close to the γ-phosphate transiently accepts a proton and thus acts as catalytic base. In the second step, the proton is transferred back from the catalytic base to the γ-phosphate, yielding ADP + H2PO4 -. These two chemical reaction steps are followed by rearrangements of the hydrogen bond network and the coordination of the Mg2+ ion. The rate constant estimated from the computed free energy barriers is in very good agreement with experiments. The overall free energy change of the reaction is close to zero, suggesting that phosphate bond cleavage itself does not provide a power stroke for conformational changes. Instead, ATP binding is essential for tight dimerization of the nucleotide-binding domains and the transition of the transmembrane domains from inward- to outward-facing, whereas ATP hydrolysis resets the conformational cycle. The mechanism is likely relevant for all ABC transporters and might have implications also for other NTPases, as many residues involved in nucleotide binding and hydrolysis are strictly conserved.
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Affiliation(s)
- Marten Prieß
- Theoretical
Chemistry, Faculty of Chemistry and Biochemistry, Ruhr-University Bochum, D-44780 Bochum, Germany
| | - Hendrik Göddeke
- Theoretical
Chemistry, Faculty of Chemistry and Biochemistry, Ruhr-University Bochum, D-44780 Bochum, Germany
| | - Gerrit Groenhof
- Department
of Chemistry and Nanoscience Center, University
of Jyväskylä, P.O. Box
35, FI-40014 Jyväskylä, Finland
| | - Lars V. Schäfer
- Theoretical
Chemistry, Faculty of Chemistry and Biochemistry, Ruhr-University Bochum, D-44780 Bochum, Germany
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23
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Grigorenko BL, Khrenova MG, Nemukhin AV. Amide-imide tautomerization in the glutamine side chain in enzymatic and photochemical reactions in proteins. Phys Chem Chem Phys 2018; 20:23827-23836. [PMID: 30202846 DOI: 10.1039/c8cp04817g] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Amide-imide tautomerization presents a pervasive class of chemical transformations in organic chemistry of natural compounds. In this Perspective, we describe two distinctively different protein systems, in which the amide-imide tautomerization in the glutamine side chain takes place in enzymatic or photochemical reactions. First, hydrolysis of guanosine triphosphate (GTP) catalyzed by the Ras-GAP protein complex suggests the occurrence of the imide tautomer of glutamine in reaction intermediates. Second, photoexcitation of flavin-binding protein domains (BLUFs) initiates a chain of reactions in the chromophore-binding pocket, including amide-imide tautomerization of glutamine. Mechanisms of these reactions at the atomic level have been revealed in quantum mechanics/molecular mechanics (QM/MM) simulations. To reinforce conclusions on the critical role of amide-imide tautomerization of glutamine in these reactions we describe results of new quantum chemistry and QM/MM calculations for relevant molecular model systems. We reexamine results of the recent IR spectroscopy studies of BLUF domains, which provide experimental evidences of Gln tautomerization in proteins. We also propose to validate the glutamine-assisted mechanism of enzymatic GTP hydrolysis by using IR spectroscopy in a proper range of wavenumbers.
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Affiliation(s)
- Bella L Grigorenko
- Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory 1/3, 119991 Moscow, Russian Federation.
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24
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Roston D, Lu X, Fang D, Demapan D, Cui Q. Analysis of Phosphoryl-Transfer Enzymes with QM/MM Free Energy Simulations. Methods Enzymol 2018; 607:53-90. [PMID: 30149869 DOI: 10.1016/bs.mie.2018.05.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
We discuss the application of quantum mechanics/molecular mechanics (QM/MM) free energy simulations to the analysis of phosphoryl transfers catalyzed by two enzymes: alkaline phosphatase and myosin. We focus on the nature of the transition state and the issue of mechanochemical coupling, respectively, in the two enzymes. The results illustrate unique insights that emerged from the QM/MM simulations, especially concerning the interpretation of experimental data regarding the nature of enzymatic transition states and coupling between global structural transition and catalysis in the active site. We also highlight a number of technical issues worthy of attention when applying QM/MM free energy simulations, and comment on a number of technical and mechanistic issues that require further studies.
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Affiliation(s)
- Daniel Roston
- Department of Chemistry and Theoretical Chemistry Institute, University of Wisconsin, Madison, Madison, WI, United States
| | - Xiya Lu
- Department of Chemistry and Theoretical Chemistry Institute, University of Wisconsin, Madison, Madison, WI, United States
| | - Dong Fang
- Department of Chemistry and Theoretical Chemistry Institute, University of Wisconsin, Madison, Madison, WI, United States
| | - Darren Demapan
- Department of Chemistry and Theoretical Chemistry Institute, University of Wisconsin, Madison, Madison, WI, United States
| | - Qiang Cui
- Department of Chemistry and Theoretical Chemistry Institute, University of Wisconsin, Madison, Madison, WI, United States.
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25
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Šponer J, Bussi G, Krepl M, Banáš P, Bottaro S, Cunha RA, Gil-Ley A, Pinamonti G, Poblete S, Jurečka P, Walter NG, Otyepka M. RNA Structural Dynamics As Captured by Molecular Simulations: A Comprehensive Overview. Chem Rev 2018; 118:4177-4338. [PMID: 29297679 PMCID: PMC5920944 DOI: 10.1021/acs.chemrev.7b00427] [Citation(s) in RCA: 357] [Impact Index Per Article: 59.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Indexed: 12/14/2022]
Abstract
With both catalytic and genetic functions, ribonucleic acid (RNA) is perhaps the most pluripotent chemical species in molecular biology, and its functions are intimately linked to its structure and dynamics. Computer simulations, and in particular atomistic molecular dynamics (MD), allow structural dynamics of biomolecular systems to be investigated with unprecedented temporal and spatial resolution. We here provide a comprehensive overview of the fast-developing field of MD simulations of RNA molecules. We begin with an in-depth, evaluatory coverage of the most fundamental methodological challenges that set the basis for the future development of the field, in particular, the current developments and inherent physical limitations of the atomistic force fields and the recent advances in a broad spectrum of enhanced sampling methods. We also survey the closely related field of coarse-grained modeling of RNA systems. After dealing with the methodological aspects, we provide an exhaustive overview of the available RNA simulation literature, ranging from studies of the smallest RNA oligonucleotides to investigations of the entire ribosome. Our review encompasses tetranucleotides, tetraloops, a number of small RNA motifs, A-helix RNA, kissing-loop complexes, the TAR RNA element, the decoding center and other important regions of the ribosome, as well as assorted others systems. Extended sections are devoted to RNA-ion interactions, ribozymes, riboswitches, and protein/RNA complexes. Our overview is written for as broad of an audience as possible, aiming to provide a much-needed interdisciplinary bridge between computation and experiment, together with a perspective on the future of the field.
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Affiliation(s)
- Jiří Šponer
- Institute of Biophysics of the Czech Academy of Sciences , Kralovopolska 135 , Brno 612 65 , Czech Republic
| | - Giovanni Bussi
- Scuola Internazionale Superiore di Studi Avanzati , Via Bonomea 265 , Trieste 34136 , Italy
| | - Miroslav Krepl
- Institute of Biophysics of the Czech Academy of Sciences , Kralovopolska 135 , Brno 612 65 , Czech Republic
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science , Palacky University Olomouc , 17. listopadu 12 , Olomouc 771 46 , Czech Republic
| | - Pavel Banáš
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science , Palacky University Olomouc , 17. listopadu 12 , Olomouc 771 46 , Czech Republic
| | - Sandro Bottaro
- Structural Biology and NMR Laboratory, Department of Biology , University of Copenhagen , Copenhagen 2200 , Denmark
| | - Richard A Cunha
- Scuola Internazionale Superiore di Studi Avanzati , Via Bonomea 265 , Trieste 34136 , Italy
| | - Alejandro Gil-Ley
- Scuola Internazionale Superiore di Studi Avanzati , Via Bonomea 265 , Trieste 34136 , Italy
| | - Giovanni Pinamonti
- Scuola Internazionale Superiore di Studi Avanzati , Via Bonomea 265 , Trieste 34136 , Italy
| | - Simón Poblete
- Scuola Internazionale Superiore di Studi Avanzati , Via Bonomea 265 , Trieste 34136 , Italy
| | - Petr Jurečka
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science , Palacky University Olomouc , 17. listopadu 12 , Olomouc 771 46 , Czech Republic
| | - Nils G Walter
- Single Molecule Analysis Group and Center for RNA Biomedicine, Department of Chemistry , University of Michigan , Ann Arbor , Michigan 48109 , United States
| | - Michal Otyepka
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science , Palacky University Olomouc , 17. listopadu 12 , Olomouc 771 46 , Czech Republic
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26
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Petrović D, Szeler K, Kamerlin SCL. Challenges and advances in the computational modeling of biological phosphate hydrolysis. Chem Commun (Camb) 2018; 54:3077-3089. [PMID: 29412205 DOI: 10.1039/c7cc09504j] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Phosphate ester hydrolysis is fundamental to many life processes, and has been the topic of substantial experimental and computational research effort. However, even the simplest of phosphate esters can be hydrolyzed through multiple possible pathways that can be difficult to distinguish between, either experimentally, or computationally. Therefore, the mechanisms of both the enzymatic and non-enzymatic reactions have been historically controversial. In the present contribution, we highlight a number of technical issues involved in reliably modeling these computationally challenging reactions, as well as proposing potential solutions. We also showcase examples of our own work in this area, discussing both the non-enzymatic reaction in aqueous solution, as well as insights obtained from the computational modeling of organophosphate hydrolysis and catalytic promiscuity amongst enzymes that catalyze phosphoryl transfer.
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Affiliation(s)
- Dušan Petrović
- Department of Cell and Molecular Biology, Uppsala University, BMC Box 596, S-751 24 Uppsala, Sweden.
| | - Klaudia Szeler
- Department of Cell and Molecular Biology, Uppsala University, BMC Box 596, S-751 24 Uppsala, Sweden.
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27
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Lai J, Ghaemi Z, Luthey-Schulten Z. The Conformational Change in Elongation Factor Tu Involves Separation of Its Domains. Biochemistry 2017; 56:5972-5979. [PMID: 29045140 DOI: 10.1021/acs.biochem.7b00591] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Elongation factor Tu (EF-Tu) is a highly conserved GTPase that is responsible for supplying the aminoacylated tRNA to the ribosome. Upon binding to the ribosome, EF-Tu undergoes GTP hydrolysis, which drives a major conformational change, triggering the release of aminoacylated tRNA to the ribosome. Using a combination of molecular simulation techniques, we studied the transition between the pre- and post-hydrolysis structures through two distinct pathways. We show that the transition free energy is minimal along a non-intuitive pathway that involves "separation" of the GTP binding domain (domain 1) from the OB folds (domains 2 and 3), followed by domain 1 rotation, and, eventually, locking the EF-Tu conformation in the post-hydrolysis state. The domain separation also leads to a slight extension of the linker connecting domain 1 to domain 2. Using docking tools and correlation-based analysis, we identified and characterized the EF-Tu conformations that release the tRNA. These calculations suggest that EF-Tu can release the tRNA before the domains separate and after domain 1 rotates by 25°. We also examined the EF-Tu conformations in the context of the ribosome. Given the high degrees of sequence similarity with other translational GTPases, we predict a similar separation mechanism is followed.
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Affiliation(s)
- Jonathan Lai
- Department of Chemistry, University of Illinois at Urbana-Champaign , Urbana, Illinois 61801, United States
| | - Zhaleh Ghaemi
- Department of Chemistry, University of Illinois at Urbana-Champaign , Urbana, Illinois 61801, United States
| | - Zaida Luthey-Schulten
- Department of Chemistry, University of Illinois at Urbana-Champaign , Urbana, Illinois 61801, United States.,Center for the Physics of Living Cells, University of Illinois at Urbana-Champaign , Urbana, Illinois 61801, United States.,Beckman Institute, University of Illinois at Urbana-Champaign , Urbana, Illinois 61801, United States.,Carl Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign , Urbana, Illinois 61801, United States
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28
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Jin Y, Molt RW, Pellegrini E, Cliff MJ, Bowler MW, Richards NGJ, Blackburn GM, Waltho JP. Assessing the Influence of Mutation on GTPase Transition States by Using X-ray Crystallography, 19 F NMR, and DFT Approaches. Angew Chem Int Ed Engl 2017; 56:9732-9735. [PMID: 28498638 PMCID: PMC5575484 DOI: 10.1002/anie.201703074] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Indexed: 11/08/2022]
Abstract
We report X-ray crystallographic and 19 F NMR studies of the G-protein RhoA complexed with MgF3- , GDP, and RhoGAP, which has the mutation Arg85'Ala. When combined with DFT calculations, these data permit the identification of changes in transition state (TS) properties. The X-ray data show how Tyr34 maintains solvent exclusion and the core H-bond network in the active site by relocating to replace the missing Arg85' sidechain. The 19 F NMR data show deshielding effects that indicate the main function of Arg85' is electronic polarization of the transferring phosphoryl group, primarily mediated by H-bonding to O3G and thence to PG . DFT calculations identify electron-density redistribution and pinpoint why the TS for guanosine 5'-triphosphate (GTP) hydrolysis is higher in energy when RhoA is complexed with RhoGAPArg85'Ala relative to wild-type (WT) RhoGAP. This study demonstrates that 19 F NMR measurements, in combination with X-ray crystallography and DFT calculations, can reliably dissect the response of small GTPases to site-specific modifications.
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Affiliation(s)
- Yi Jin
- Department of Molecular Biology and Biotechnology, Krebs Institute, University of Sheffield, Sheffield, S10 2TN, UK.,School of Chemistry, Cardiff University, Cardiff, CF10 3AT, UK
| | - Robert W Molt
- School of Chemistry, Cardiff University, Cardiff, CF10 3AT, UK.,Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, 46202, USA.,ENSCO, Inc., Melbourne, FL, 32940, USA
| | - Erika Pellegrini
- Structural Biology Group, ESRF-The European Synchrotron, CS40220, 38043, Grenoble, Cedex 9, France
| | - Matthew J Cliff
- Manchester Institute of Biotechnology, Manchester, M1 7DN, UK
| | - Matthew W Bowler
- Structural Biology Group, ESRF-The European Synchrotron, CS40220, 38043, Grenoble, Cedex 9, France.,European Molecular Biology Laboratory, Grenoble Outstation CS90181, 38042, Grenoble, Cedex 9, France
| | | | - G Michael Blackburn
- Department of Molecular Biology and Biotechnology, Krebs Institute, University of Sheffield, Sheffield, S10 2TN, UK
| | - Jonathan P Waltho
- Department of Molecular Biology and Biotechnology, Krebs Institute, University of Sheffield, Sheffield, S10 2TN, UK.,Manchester Institute of Biotechnology, Manchester, M1 7DN, UK
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29
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Gerwert K, Mann D, Kötting C. Common mechanisms of catalysis in small and heterotrimeric GTPases and their respective GAPs. Biol Chem 2017; 398:523-533. [PMID: 28245182 DOI: 10.1515/hsz-2016-0314] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Accepted: 02/15/2017] [Indexed: 01/15/2023]
Abstract
GTPases are central switches in cells. Their dysfunctions are involved in severe diseases. The small GTPase Ras regulates cell growth, differentiation and apoptosis by transmitting external signals to the nucleus. In one group of oncogenic mutations, the 'switch-off' reaction is inhibited, leading to persistent activation of the signaling pathway. The switch reaction is regulated by GTPase-activating proteins (GAPs), which catalyze GTP hydrolysis in Ras, and by guanine nucleotide exchange factors, which catalyze the exchange of GDP for GTP. Heterotrimeric G-proteins are activated by G-protein coupled receptors and are inactivated by GTP hydrolysis in the Gα subunit. Their GAPs are called regulators of G-protein signaling. In the same way that Ras serves as a prototype for small GTPases, Gαi1 is the most well-studied Gα subunit. By utilizing X-ray structural models, time-resolved infrared-difference spectroscopy, and biomolecular simulations, we elucidated the detailed molecular reaction mechanism of the GTP hydrolysis in Ras and Gαi1. In both proteins, the charge distribution of GTP is driven towards the transition state, and an arginine is precisely positioned to facilitate nucleophilic attack of water. In addition to these mechanistic details of GTP hydrolysis, Ras dimerization as an emerging factor in signal transduction is discussed in this review.
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Affiliation(s)
- Klaus Gerwert
- Department of Biophysics, Ruhr-University Bochum, Universitätsstrasse 150, D-44801 Bochum
| | - Daniel Mann
- Department of Biophysics, Ruhr-University Bochum, Universitätsstrasse 150, D-44801 Bochum
| | - Carsten Kötting
- Department of Biophysics, Ruhr-University Bochum, Universitätsstrasse 150, D-44801 Bochum
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30
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Barrozo A, Blaha-Nelson D, Williams NH, Kamerlin SCL. The effect of magnesium ions on triphosphate hydrolysis. PURE APPL CHEM 2017. [DOI: 10.1515/pac-2016-1125] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
AbstractThe role of metal ions in catalyzing phosphate ester hydrolysis has been the subject of much debate, both in terms of whether they change the transition state structure or mechanistic pathway. Understanding the impact of metal ions on these biologically critical reactions is central to improving our understanding of the role of metal ions in the numerous enzymes that facilitate them. In the present study, we have performed density functional theory studies of the mechanisms of methyl triphosphate and acetyl phosphate hydrolysis in aqueous solution to explore the competition between solvent- and substrate-assisted pathways, and examined the impact of Mg2+ on the energetics and transition state geometries. In both cases, we observe a clear preference for a more dissociative solvent-assisted transition state, which is not significantly changed by coordination of Mg2+. The effect of Mg2+ on the transition state geometries for the two pathways is minimal. While our calculations cannot rule out a substrate-assisted pathway as a possible solution for biological phosphate hydrolysis, they demonstrate that a significantly higher energy barrier needs to be overcome in the enzymatic reaction for this to be an energetically viable reaction pathway.
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Affiliation(s)
- Alexandre Barrozo
- Department of Chemistry, University of Southern California, Los Angeles, CA 90089-1062, USA
| | - David Blaha-Nelson
- Department of Cell and Molecular Biology, Uppsala University, BMC Box 596, S-751 24 Uppsala, Sweden
| | | | - Shina C. L. Kamerlin
- Department of Cell and Molecular Biology, Uppsala University, BMC Box 596, S-751 24 Uppsala, Sweden
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31
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Jin Y, Molt RW, Pellegrini E, Cliff MJ, Bowler MW, Richards NGJ, Blackburn GM, Waltho JP. Assessing the Influence of Mutation on GTPase Transition States by Using X‐ray Crystallography,
19
F NMR, and DFT Approaches. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201703074] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Yi Jin
- Department of Molecular Biology and BiotechnologyKrebs InstituteUniversity of Sheffield Sheffield S10 2TN UK
- School of ChemistryCardiff University Cardiff CF10 3AT UK
| | - Robert W. Molt
- School of ChemistryCardiff University Cardiff CF10 3AT UK
- Department of Biochemistry and Molecular BiologyIndiana University School of Medicine Indianapolis IN 46202 USA
- ENSCO, Inc. Melbourne FL 32940 USA
| | - Erika Pellegrini
- Structural Biology GroupESRF-The European Synchrotron, CS40220 38043 Grenoble, Cedex 9 France
| | | | - Matthew W. Bowler
- Structural Biology GroupESRF-The European Synchrotron, CS40220 38043 Grenoble, Cedex 9 France
- European Molecular Biology Laboratory, Grenoble Outstation CS90181 38042 Grenoble, Cedex 9 France
| | | | - G. Michael Blackburn
- Department of Molecular Biology and BiotechnologyKrebs InstituteUniversity of Sheffield Sheffield S10 2TN UK
| | - Jonathan P. Waltho
- Department of Molecular Biology and BiotechnologyKrebs InstituteUniversity of Sheffield Sheffield S10 2TN UK
- Manchester Institute of Biotechnology Manchester M1 7DN UK
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32
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Zala D, Schlattner U, Desvignes T, Bobe J, Roux A, Chavrier P, Boissan M. The advantage of channeling nucleotides for very processive functions. F1000Res 2017; 6:724. [PMID: 28663786 PMCID: PMC5473427 DOI: 10.12688/f1000research.11561.2] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 07/17/2017] [Indexed: 12/26/2022] Open
Abstract
Nucleoside triphosphate (NTP)s, like ATP (adenosine 5'-triphosphate) and GTP (guanosine 5'-triphosphate), have long been considered sufficiently concentrated and diffusible to fuel all cellular ATPases (adenosine triphosphatases) and GTPases (guanosine triphosphatases) in an energetically healthy cell without becoming limiting for function. However, increasing evidence for the importance of local ATP and GTP pools, synthesised in close proximity to ATP- or GTP-consuming reactions, has fundamentally challenged our view of energy metabolism. It has become evident that cellular energy metabolism occurs in many specialised 'microcompartments', where energy in the form of NTPs is transferred preferentially from NTP-generating modules directly to NTP-consuming modules. Such energy channeling occurs when diffusion through the cytosol is limited, where these modules are physically close and, in particular, if the NTP-consuming reaction has a very high turnover, i.e. is very processive. Here, we summarise the evidence for these conclusions and describe new insights into the physiological importance and molecular mechanisms of energy channeling gained from recent studies. In particular, we describe the role of glycolytic enzymes for axonal vesicle transport and nucleoside diphosphate kinases for the functions of dynamins and dynamin-related GTPases.
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Affiliation(s)
- Diana Zala
- ESPCI - Paris, PSL Research University, Paris, F-75005, France.,CNRS, UMR8249, Paris, F-75005, France
| | - Uwe Schlattner
- Laboratory of Fundamental and Applied Bioenergetics (LBFA), and SFR Environmental and Systems Biology (BEeSy), U1055, University Grenoble Alpes, Grenoble, 38058, France.,Inserm-U1055, Grenoble, F-38058, France
| | - Thomas Desvignes
- Institute of Neuroscience, University of Oregon, Eugene, OR, 97401, USA
| | - Julien Bobe
- INRA, UR1037 LPGP, Campus de Beaulieu, Rennes, F-35000, France
| | - Aurélien Roux
- Department of Biochemistry, University of Geneva, Geneva, CH-1211, Switzerland.,Swiss National Centre for Competence in Research Programme Chemical Biology, Geneva, CH-1211, Switzerland
| | - Philippe Chavrier
- Institut Curie, Paris, F-75248, France.,PSL Research University, Paris, F-75005, France.,CNRS, UMR144, Paris, F-75248, France
| | - Mathieu Boissan
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, UMRS938, Saint-Antoine Research Center, Paris, F-75012, France.,AP-HP, Hospital Tenon, Service de Biochimie et Hormonologie, Paris, F-75020, France
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33
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Zala D, Schlattner U, Desvignes T, Bobe J, Roux A, Chavrier P, Boissan M. The advantage of channeling nucleotides for very processive functions. F1000Res 2017; 6:724. [PMID: 28663786 DOI: 10.12688/f1000research.11561.1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/15/2017] [Indexed: 01/01/2023] Open
Abstract
Nucleoside triphosphate (NTP)s, like ATP (adenosine 5'-triphosphate) and GTP (guanosine 5'-triphosphate), have long been considered sufficiently concentrated and diffusible to fuel all cellular ATPases (adenosine triphosphatases) and GTPases (guanosine triphosphatases) in an energetically healthy cell without becoming limiting for function. However, increasing evidence for the importance of local ATP and GTP pools, synthesised in close proximity to ATP- or GTP-consuming reactions, has fundamentally challenged our view of energy metabolism. It has become evident that cellular energy metabolism occurs in many specialised 'microcompartments', where energy in the form of NTPs is transferred preferentially from NTP-generating modules directly to NTP-consuming modules. Such energy channeling occurs when diffusion through the cytosol is limited, where these modules are physically close and, in particular, if the NTP-consuming reaction has a very high turnover, i.e. is very processive. Here, we summarise the evidence for these conclusions and describe new insights into the physiological importance and molecular mechanisms of energy channeling gained from recent studies. In particular, we describe the role of glycolytic enzymes for axonal vesicle transport and nucleoside diphosphate kinases for the functions of dynamins and dynamin-related GTPases.
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Affiliation(s)
- Diana Zala
- ESPCI - Paris, PSL Research University, Paris, F-75005, France.,CNRS, UMR8249, Paris, F-75005, France
| | - Uwe Schlattner
- Laboratory of Fundamental and Applied Bioenergetics (LBFA), and SFR Environmental and Systems Biology (BEeSy), U1055, University Grenoble Alpes, Grenoble, 38058, France.,Inserm-U1055, Grenoble, F-38058, France
| | - Thomas Desvignes
- Institute of Neuroscience, University of Oregon, Eugene, OR, 97401, USA
| | - Julien Bobe
- INRA, UR1037 LPGP, Campus de Beaulieu, Rennes, F-35000, France
| | - Aurélien Roux
- Department of Biochemistry, University of Geneva, Geneva, CH-1211, Switzerland.,Swiss National Centre for Competence in Research Programme Chemical Biology, Geneva, CH-1211, Switzerland
| | - Philippe Chavrier
- Institut Curie, Paris, F-75248, France.,PSL Research University, Paris, F-75005, France.,CNRS, UMR144, Paris, F-75248, France
| | - Mathieu Boissan
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, UMRS938, Saint-Antoine Research Center, Paris, F-75012, France.,AP-HP, Hospital Tenon, Service de Biochimie et Hormonologie, Paris, F-75020, France
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34
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Maracci C, Rodnina MV. Review: Translational GTPases. Biopolymers 2017; 105:463-75. [PMID: 26971860 PMCID: PMC5084732 DOI: 10.1002/bip.22832] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Revised: 03/09/2016] [Accepted: 03/10/2016] [Indexed: 01/26/2023]
Abstract
Translational GTPases (trGTPases) play key roles in facilitating protein synthesis on the ribosome. Despite the high degree of evolutionary conservation in the sequences of their GTP-binding domains, the rates of GTP hydrolysis and nucleotide exchange vary broadly between different trGTPases. EF-Tu, one of the best-characterized model G proteins, evolved an exceptionally rapid and tightly regulated GTPase activity, which ensures rapid and accurate incorporation of amino acids into the nascent chain. Other trGTPases instead use the energy of GTP hydrolysis to promote movement or to ensure the forward commitment of translation reactions. Recent data suggest the GTPase mechanism of EF-Tu and provide an insight in the catalysis of GTP hydrolysis by its unusual activator, the ribosome. Here we summarize these advances in understanding the functional cycle and the regulation of trGTPases, stimulated by the elucidation of their structures on the ribosome and the progress in dissecting the reaction mechanism of GTPases. © 2016 Wiley Periodicals, Inc. Biopolymers 105: 463-475, 2016.
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Affiliation(s)
- Cristina Maracci
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, Goettingen, 37077, Germany
| | - Marina V Rodnina
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, Goettingen, 37077, Germany
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35
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Tripathi R, Glaves R, Marx D. The GTPase hGBP1 converts GTP to GMP in two steps via proton shuttle mechanisms. Chem Sci 2017; 8:371-380. [PMID: 28451182 PMCID: PMC5365056 DOI: 10.1039/c6sc02045c] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Accepted: 08/21/2016] [Indexed: 11/21/2022] Open
Abstract
GTPases play a crucial role in the regulation of many biological processes by catalyzing the hydrolysis of GTP into GDP. The focus of this work is on the dynamin-related large GTPase human guanine nucleotide binding protein-1 (hGBP1) which is able to hydrolyze GTP even to GMP. Here, we studied the largely unknown mechanisms of both GTP and GDP hydrolysis steps utilizing accelerated ab initio QM/MM metadynamics simulations to compute multi-dimensional free energy landscapes. We find an indirect substrate-assisted catalysis (SAC) mechanism for GTP hydrolysis involving transfer of a proton from the water nucleophile to a nonbridging phosphoryl oxygen via a proton relay pathway where the rate-determining first step is concerted-dissociative nature. A "composite base" consisting of Ser73, Glu99, a bridging water molecule, and GTP was found to activate the nucleophilic water, thus disclosing the complex nature of the general base in hGBP1. A nearly two-fold reduction in the free energy barrier was obtained for GTP hydrolysis in the enzyme in comparison to bulk solvent. The subsequent GDP hydrolysis in hGBP1 was also found to follow a water-mediated proton shuttle mechanism. It is expected that the proton shuttle mechanisms unravelled for hGBP1 apply to many classes of GTPases/ATPases that possess an optimally-arranged hydrogen bonding network, which connects the catalytic water to a proton acceptor.
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Affiliation(s)
- Ravi Tripathi
- Lehrstuhl für Theoretische Chemie , Ruhr-Universität Bochum , 44780 Bochum , Germany .
| | - Rachel Glaves
- Lehrstuhl für Theoretische Chemie , Ruhr-Universität Bochum , 44780 Bochum , Germany .
| | - Dominik Marx
- Lehrstuhl für Theoretische Chemie , Ruhr-Universität Bochum , 44780 Bochum , Germany .
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36
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Vithani N, Batra S, Prakash B, Nair NN. Elucidating the GTP Hydrolysis Mechanism in FeoB: A Hydrophobic Amino-Acid Substituted GTPase. ACS Catal 2016. [DOI: 10.1021/acscatal.6b03365] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Neha Vithani
- Department
of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur 208016, India
| | - Sahil Batra
- Department
of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur 208016, India
| | - Balaji Prakash
- Department
of Molecular Nutrition, CSIR-Central Food Technological Research Institute, Mysore, 570020, India
| | - Nisanth N. Nair
- Department
of Chemistry, Indian Institute of Technology, Kanpur 208016, India
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37
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Mechanism of the intrinsic arginine finger in heterotrimeric G proteins. Proc Natl Acad Sci U S A 2016; 113:E8041-E8050. [PMID: 27911799 DOI: 10.1073/pnas.1612394113] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Heterotrimeric G proteins are crucial molecular switches that maintain a large number of physiological processes in cells. The signal is encoded into surface alterations of the Gα subunit that carries GTP in its active state and GDP in its inactive state. The ability of the Gα subunit to hydrolyze GTP is essential for signal termination. Regulator of G protein signaling (RGS) proteins accelerates this process. A key player in this catalyzed reaction is an arginine residue, Arg178 in Gαi1, which is already an intrinsic part of the catalytic center in Gα in contrast to small GTPases, at which the corresponding GTPase-activating protein (GAP) provides the arginine "finger." We applied time-resolved FTIR spectroscopy in combination with isotopic labeling and site-directed mutagenesis to reveal the molecular mechanism, especially of the role of Arg178 in the intrinsic Gαi1 mechanism and the RGS4-catalyzed mechanism. Complementary biomolecular simulations (molecular mechanics with molecular dynamics and coupled quantum mechanics/molecular mechanics) were performed. Our findings show that Arg178 is bound to γ-GTP for the intrinsic Gαi1 mechanism and pushed toward a bidentate α-γ-GTP coordination for the Gαi1·RGS4 mechanism. This movement induces a charge shift toward β-GTP, increases the planarity of γ-GTP, and thereby catalyzes the hydrolysis.
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38
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Khrenova MG, Grigorenko BL, Nemukhin AV. Theoretical vibrational spectroscopy of intermediates and the reaction mechanism of the guanosine triphosphate hydrolysis by the protein complex Ras-GAP. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2016; 166:68-72. [PMID: 27214270 DOI: 10.1016/j.saa.2016.04.056] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2015] [Revised: 04/17/2016] [Accepted: 04/27/2016] [Indexed: 06/05/2023]
Abstract
The structures and vibrational spectra of the reacting species upon guanosine triphosphate (GTP) hydrolysis to guanosine diphosphate and inorganic phosphate (Pi) trapped inside the protein complex Ras-GAP were analyzed following the results of QM/MM simulations. The frequencies of the phosphate vibrations referring to the reactants and to Pi were compared to those observed in the experimental FTIR studies. A good correlation between the theoretical and experimental vibrational data provides a strong support to the reaction mechanism of GTP hydrolysis by the Ras-GAP enzyme system revealed by the recent QM/MM modeling. Evolution of the vibrational bands associated with the inorganic phosphate Pi during the elementary stages of GTP hydrolysis is predicted.
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Affiliation(s)
- Maria G Khrenova
- Chemistry Department, M.V. Lomonosov Moscow State University, 1-3 Leninskie Gory, Moscow 119991, Russia
| | - Bella L Grigorenko
- Chemistry Department, M.V. Lomonosov Moscow State University, 1-3 Leninskie Gory, Moscow 119991, Russia; N.M. Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, 4 Kosygin Street, Moscow 119334, Russia
| | - Alexander V Nemukhin
- Chemistry Department, M.V. Lomonosov Moscow State University, 1-3 Leninskie Gory, Moscow 119991, Russia; N.M. Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, 4 Kosygin Street, Moscow 119334, Russia.
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39
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Mishra AK, Lambright DG. Invited review: Small GTPases and their GAPs. Biopolymers 2016; 105:431-48. [PMID: 26972107 PMCID: PMC5439442 DOI: 10.1002/bip.22833] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Revised: 02/16/2016] [Accepted: 03/10/2016] [Indexed: 12/11/2022]
Abstract
Widespread utilization of small GTPases as major regulatory hubs in many different biological systems derives from a conserved conformational switch mechanism that facilitates cycling between GTP-bound active and GDP-bound inactive states under control of guanine nucleotide exchange factors (GEFs) and GTPase activating proteins (GAPs), which accelerate slow intrinsic rates of activation by nucleotide exchange and deactivation by GTP hydrolysis, respectively. Here we review developments leading to current understanding of intrinsic and GAP catalyzed GTP hydrolytic reactions in small GTPases from structural, molecular and chemical mechanistic perspectives. Despite the apparent simplicity of the GTPase cycle, the structural bases underlying the hallmark hydrolytic reaction and catalytic acceleration by GAPs are considerably more diverse than originally anticipated. Even the most fundamental aspects of the reaction mechanism have been challenging to decipher. Through a combination of experimental and in silico approaches, the outlines of a consensus view have begun to emerge for the best studied paradigms. Nevertheless, recent observations indicate that there is still much to be learned. © 2016 Wiley Periodicals, Inc. Biopolymers 105: 431-448, 2016.
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Affiliation(s)
- Ashwini K Mishra
- Program in Molecular Medicine and Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA, 01605
| | - David G Lambright
- Program in Molecular Medicine and Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA, 01605
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40
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Khrenova MG, Kots ED, Nemukhin AV. Reaction Mechanism of Guanosine Triphosphate Hydrolysis by the Vision-Related Protein Complex Arl3-RP2. J Phys Chem B 2016; 120:3873-9. [PMID: 27043216 DOI: 10.1021/acs.jpcb.6b03363] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Complexes of small GTPases with GTPase-activating proteins have been intensively studied with the main focus on the complex of H-Ras with p120GAP (Ras-GAP). The detailed mechanism of GTP hydrolysis is still unresolved. To clarify it, we calculated the energy profile of GTP hydrolysis in the active site of a recently characterized vision-related member of this family, the Arl3-RP2 complex. The mechanism suggested in this study retains the main features of GTP hydrolysis by the Ras-GAP complex, but the relative energies of the corresponding intermediates are different and an additional intermediate exists in the Arl3-RP2 complex compared with the Ras-GAP. These differences arise from small deviations in the catalytic arginine conformation of the active site. In the Arl3-RP2 complex, the first two intermediates, corresponding to the Pγ-Oβγ bond cleavage and the glutamine-assisted proton transfer, are almost isoenergetic with the ES complex. Numerical simulations of the kinetic curves demonstrate that the concentrations of these intermediates are comparable with that of ES during the reaction. The calculated IR spectra reveal specific vibrational bands, corresponding to these intermediates. These specific features of the Arl3-RP2 complex open the opportunity to identify spectroscopically two more reaction intermediates in GTP hydrolysis in addition to the ES and EP complexes.
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Affiliation(s)
- Maria G Khrenova
- Chemistry Department, Lomonosov Moscow State University , Leninskie Gory 1/3, Moscow, 119991, Russian Federation
| | - Ekaterina D Kots
- Chemistry Department, Lomonosov Moscow State University , Leninskie Gory 1/3, Moscow, 119991, Russian Federation.,N. M. Emanuel Institute of Biochemical Physics, Russian Academy of Sciences , Kosygina 4, Moscow, 119334, Russian Federation
| | - Alexander V Nemukhin
- Chemistry Department, Lomonosov Moscow State University , Leninskie Gory 1/3, Moscow, 119991, Russian Federation.,N. M. Emanuel Institute of Biochemical Physics, Russian Academy of Sciences , Kosygina 4, Moscow, 119334, Russian Federation
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41
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Jin Y, Molt RW, Waltho JP, Richards NGJ, Blackburn GM. (19)F NMR and DFT Analysis Reveal Structural and Electronic Transition State Features for RhoA-Catalyzed GTP Hydrolysis. Angew Chem Int Ed Engl 2016; 55:3318-22. [PMID: 26822702 PMCID: PMC4770445 DOI: 10.1002/anie.201509477] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Revised: 01/14/2016] [Indexed: 11/13/2022]
Abstract
Molecular details for RhoA/GAP catalysis of the hydrolysis of GTP to GDP are poorly understood. We use (19)F NMR chemical shifts in the MgF3(-) transition state analogue (TSA) complex as a spectroscopic reporter to indicate electron distribution for the γ-PO3(-) oxygens in the corresponding TS, implying that oxygen coordinated to Mg has the greatest electron density. This was validated by QM calculations giving a picture of the electronic properties of the transition state (TS) for nucleophilic attack of water on the γ-PO3(-) group based on the structure of a RhoA/GAP-GDP-MgF3(-) TSA complex. The TS model displays a network of 20 hydrogen bonds, including the GAP Arg85' side chain, but neither phosphate torsional strain nor general base catalysis is evident. The nucleophilic water occupies a reactive location different from that in multiple ground state complexes, arising from reorientation of the Gln-63 carboxamide by Arg85' to preclude direct hydrogen bonding from water to the target γ-PO3(-) group.
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Affiliation(s)
- Yi Jin
- Krebs Institute, Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, UK
| | - Robert W Molt
- Department of Chemistry and Chemical Biology, Indiana University Purdue University Indianapolis, Indianapolis, IN, 46202, USA
| | - Jonathan P Waltho
- Krebs Institute, Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, UK.
- Manchester Institute of Biotechnology, Manchester, M1 7DN, UK.
| | - Nigel G J Richards
- Department of Chemistry and Chemical Biology, Indiana University Purdue University Indianapolis, Indianapolis, IN, 46202, USA.
- School of Chemistry, Cardiff University, Cardiff, CF10 3AT, UK.
| | - G Michael Blackburn
- Krebs Institute, Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, UK.
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Jin Y, Molt RW, Waltho JP, Richards NGJ, Blackburn GM. 19F NMR and DFT Analysis Reveal Structural and Electronic Transition State Features for RhoA-Catalyzed GTP Hydrolysis. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201509477] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Yi Jin
- Krebs Institute, Department of Molecular Biology and Biotechnology; University of Sheffield; Sheffield S10 2TN UK
| | - Robert W. Molt
- Department of Chemistry and Chemical Biology; Indiana University Purdue University Indianapolis; Indianapolis IN 46202 USA
| | - Jonathan P. Waltho
- Krebs Institute, Department of Molecular Biology and Biotechnology; University of Sheffield; Sheffield S10 2TN UK
- Manchester Institute of Biotechnology; Manchester M1 7DN UK
| | - Nigel G. J. Richards
- Department of Chemistry and Chemical Biology; Indiana University Purdue University Indianapolis; Indianapolis IN 46202 USA
- School of Chemistry; Cardiff University; Cardiff CF10 3AT UK
| | - G. Michael Blackburn
- Krebs Institute, Department of Molecular Biology and Biotechnology; University of Sheffield; Sheffield S10 2TN UK
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43
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Acosta-Silva C, Bertran J, Branchadell V, Oliva A. Theoretical Insights on the Mechanism of the GTP Hydrolysis Catalyzed by the Elongation Factor Tu (EF-Tu). J Phys Chem B 2015; 120:89-101. [PMID: 26653849 DOI: 10.1021/acs.jpcb.5b10145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The purpose of this work is to have a better understanding of the mechanism of GTP hydrolysis catalyzed by the elongation factor Tu. Two main aspects are being discussed in the literature: the associative or dissociative character of the process and the nature of nucleophile activation. The calculations of the QM subsystem have been done by means of the M06-2X density functional and the split valence triple-ζ 6-311+G(d,p) basis set. The environmental effect has been introduced through the continuum SMD method. We have studied three models of increasing complexity in order to analyze the different factors that intervene in the catalytic action. The results obtained in this paper confirm that the protonated His84 plays a fundamental role in the catalytic mechanism, but we have also found that the crystallographic sodium ion has a notable effect in the catalysis. So, our work has permitted a new insight, complementary to those obtained with QM/MM calculations, into this very complex process.
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Affiliation(s)
- Carles Acosta-Silva
- Departament de Química, Universitat Autònoma de Barcelona , 08193 Bellaterra, Spain
| | - Joan Bertran
- Departament de Química, Universitat Autònoma de Barcelona , 08193 Bellaterra, Spain
| | - Vicenç Branchadell
- Departament de Química, Universitat Autònoma de Barcelona , 08193 Bellaterra, Spain
| | - Antoni Oliva
- Departament de Química, Universitat Autònoma de Barcelona , 08193 Bellaterra, Spain
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44
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Khrenova MG, Grigorenko BL, Mironov VA, Nemukhin AV. Why does mutation of Gln61 in Ras by the nitro analog NGln maintain activity of Ras-GAP in hydrolysis of guanosine triphosphate? Proteins 2015; 83:2091-9. [PMID: 26370130 DOI: 10.1002/prot.24927] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Revised: 08/31/2015] [Accepted: 09/02/2015] [Indexed: 11/05/2022]
Abstract
Interpretation of the experiments showing that the Ras-GAP protein complex maintains activity in guanosine triphosphate (GTP) hydrolysis upon replacement of Glu61 in Ras with its unnatural nitro analog, NGln, is an important issue for understanding details of chemical transformations at the enzyme active site. By using molecular modeling we demonstrate that both glutamine and its nitro analog in the aci-nitro form participate in the reaction of GTP hydrolysis at the stages of proton transfer and formation of inorganic phosphate. The computed structures and the energy profiles for the complete pathway from the enzyme-substrate to enzyme-product complexes for the wild-type and mutated Ras suggest that the reaction mechanism is not affected by this mutation.
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Affiliation(s)
- Maria G Khrenova
- Chemistry Department, M.V. Lomonosov Moscow State University, 1-3 Leninskie Gory, Moscow, 119991, Russia
| | - Bella L Grigorenko
- Chemistry Department, M.V. Lomonosov Moscow State University, 1-3 Leninskie Gory, Moscow, 119991, Russia.,N.M. Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, 4 Kosygin Street, Moscow, 119334, Russia
| | - Vladimir A Mironov
- Chemistry Department, M.V. Lomonosov Moscow State University, 1-3 Leninskie Gory, Moscow, 119991, Russia
| | - Alexander V Nemukhin
- Chemistry Department, M.V. Lomonosov Moscow State University, 1-3 Leninskie Gory, Moscow, 119991, Russia.,N.M. Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, 4 Kosygin Street, Moscow, 119334, Russia
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Khrenova MG, Grigorenko BL, Kolomeisky AB, Nemukhin AV. Hydrolysis of Guanosine Triphosphate (GTP) by the Ras·GAP Protein Complex: Reaction Mechanism and Kinetic Scheme. J Phys Chem B 2015; 119:12838-45. [PMID: 26374425 DOI: 10.1021/acs.jpcb.5b07238] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Molecular mechanisms of the hydrolysis of guanosine triphosphate (GTP) to guanosine diphosphate (GDP) and inorganic phosphate (Pi) by the Ras·GAP protein complex are fully investigated by using modern modeling tools. The previously hypothesized stages of the cleavage of the phosphorus-oxygen bond in GTP and the formation of the imide form of catalytic Gln61 from Ras upon creation of Pi are confirmed by using the higher-level quantum-based calculations. The steps of the enzyme regeneration are modeled for the first time, providing a comprehensive description of the catalytic cycle. It is found that for the reaction Ras·GAP·GTP·H2O → Ras·GAP·GDP·Pi, the highest barriers correspond to the process of regeneration of the active site but not to the process of substrate cleavage. The specific shape of the energy profile is responsible for an interesting kinetic mechanism of the GTP hydrolysis. The analysis of the process using the first-passage approach and consideration of kinetic equations suggest that the overall reaction rate is a result of the balance between relatively fast transitions and low probability of states from which these transitions are taking place. Our theoretical predictions are in excellent agreement with available experimental observations on GTP hydrolysis rates.
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Affiliation(s)
- Maria G Khrenova
- Chemistry Department, M.V. Lomonosov Moscow State University , Leninskie Gory 1/3, Moscow 119991, Russian Federation
| | - Bella L Grigorenko
- Chemistry Department, M.V. Lomonosov Moscow State University , Leninskie Gory 1/3, Moscow 119991, Russian Federation.,N.M. Emanuel Institute of Biochemical Physics, Russian Academy of Sciences , Kosygina 4, Moscow 119334, Russian Federation
| | - Anatoly B Kolomeisky
- Department of Chemistry and Center for Theoretical Biological Physics, Rice University , Houston, Texas 77005, United States
| | - Alexander V Nemukhin
- Chemistry Department, M.V. Lomonosov Moscow State University , Leninskie Gory 1/3, Moscow 119991, Russian Federation.,N.M. Emanuel Institute of Biochemical Physics, Russian Academy of Sciences , Kosygina 4, Moscow 119334, Russian Federation
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Protein synthesis during cellular quiescence is inhibited by phosphorylation of a translational elongation factor. Proc Natl Acad Sci U S A 2015; 112:E3274-81. [PMID: 26056311 DOI: 10.1073/pnas.1505297112] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In nature, most organisms experience conditions that are suboptimal for growth. To survive, cells must fine-tune energy-demanding metabolic processes in response to nutrient availability. Here, we describe a novel mechanism by which protein synthesis in starved cells is down-regulated by phosphorylation of the universally conserved elongation factor Tu (EF-Tu). Phosphorylation impairs the essential GTPase activity of EF-Tu, thereby preventing its release from the ribosome. As a consequence, phosphorylated EF-Tu has a dominant-negative effect in elongation, resulting in the overall inhibition of protein synthesis. Importantly, this mechanism allows a quick and robust regulation of one of the most abundant cellular proteins. Given that the threonine that serves as the primary site of phosphorylation is conserved in all translational GTPases from bacteria to humans, this mechanism may have important implications for growth-rate control in phylogenetically diverse organisms.
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