1
|
Bao H, Wang W, Sun H, Chen J. The switch states of the GDP-bound HRAS affected by point mutations: a study from Gaussian accelerated molecular dynamics simulations and free energy landscapes. J Biomol Struct Dyn 2024; 42:3363-3381. [PMID: 37216340 DOI: 10.1080/07391102.2023.2213355] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Accepted: 05/04/2023] [Indexed: 05/24/2023]
Abstract
Point mutations play a vital role in the conformational transformation of HRAS. In this work, Gaussian accelerated molecular dynamics (GaMD) simulations followed by constructions of free energy landscapes (FELs) were adopted to explore the effect of mutations D33K, A59T and L120A on conformation states of the GDP-bound HRAS. The results from the post-processing analyses on GaMD trajectories suggest that mutations alter the flexibility and motion modes of the switch domains from HRAS. The analyses from FELs show that mutations induce more disordered states of the switch domains and affect interactions of GDP with HRAS, implying that mutations yield a vital effect on the binding of HRAS to effectors. The GDP-residue interaction network revealed by our current work indicates that salt bridges and hydrogen bonding interactions (HBIs) play key roles in the binding of GDP to HRAS. Furthermore, instability in the interactions of magnesium ions and GDP with the switch SI leads to the extreme disorder of the switch domains. This study is expected to provide the energetic basis and molecular mechanism for further understanding the function of HRAS.Communicated by Ramaswamy H. Sarma.
Collapse
Affiliation(s)
- Huayin Bao
- School of Pharmacy, Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Wei Wang
- School of Science, Shandong Jiaotong University, Jinan, China
| | - Haibo Sun
- School of Science, Shandong Jiaotong University, Jinan, China
| | - Jianzhong Chen
- School of Science, Shandong Jiaotong University, Jinan, China
| |
Collapse
|
2
|
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.
Collapse
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
| |
Collapse
|
3
|
Yu Z, Wang Z, Cui X, Cao Z, Zhang W, Sun K, Hu G. Conformational States of the GDP- and GTP-Bound HRAS Affected by A59E and K117R: An Exploration from Gaussian Accelerated Molecular Dynamics. Molecules 2024; 29:645. [PMID: 38338389 PMCID: PMC10856033 DOI: 10.3390/molecules29030645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Revised: 01/01/2024] [Accepted: 01/25/2024] [Indexed: 02/12/2024] Open
Abstract
The HRAS protein is considered a critical target for drug development in cancers. It is vital for effective drug development to understand the effects of mutations on the binding of GTP and GDP to HRAS. We conducted Gaussian accelerated molecular dynamics (GaMD) simulations and free energy landscape (FEL) calculations to investigate the impacts of two mutations (A59E and K117R) on GTP and GDP binding and the conformational states of the switch domain. Our findings demonstrate that these mutations not only modify the flexibility of the switch domains, but also affect the correlated motions of these domains. Furthermore, the mutations significantly disrupt the dynamic behavior of the switch domains, leading to a conformational change in HRAS. Additionally, these mutations significantly impact the switch domain's interactions, including their hydrogen bonding with ligands and electrostatic interactions with magnesium ions. Since the switch domains are crucial for the binding of HRAS to effectors, any alterations in their interactions or conformational states will undoubtedly disrupt the activity of HRAS. This research provides valuable information for the design of drugs targeting HRAS.
Collapse
Affiliation(s)
- Zhiping Yu
- Shandong Key Laboratory of Biophysics, Dezhou University, Dezhou 253023, China; (Z.Y.); (Z.C.)
| | - Zhen Wang
- Pingyin People’s Hospital, Jinan 250400, China; (Z.W.); (X.C.)
| | - Xiuzhen Cui
- Pingyin People’s Hospital, Jinan 250400, China; (Z.W.); (X.C.)
| | - Zanxia Cao
- Shandong Key Laboratory of Biophysics, Dezhou University, Dezhou 253023, China; (Z.Y.); (Z.C.)
| | - Wanyunfei Zhang
- School of Science, Xi’an Polytechnic University, Xi’an 710048, China; (W.Z.); (K.S.)
| | - Kunxiao Sun
- School of Science, Xi’an Polytechnic University, Xi’an 710048, China; (W.Z.); (K.S.)
| | - Guodong Hu
- Shandong Key Laboratory of Biophysics, Dezhou University, Dezhou 253023, China; (Z.Y.); (Z.C.)
| |
Collapse
|
4
|
Chen S, Zhang Z, Zhang Y, Choi T, Zhao Y. Activation Mechanism of RhoA Caused by Constitutively Activating Mutations G14V and Q63L. Int J Mol Sci 2022; 23:ijms232415458. [PMID: 36555100 PMCID: PMC9778661 DOI: 10.3390/ijms232415458] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 11/23/2022] [Accepted: 11/30/2022] [Indexed: 12/12/2022] Open
Abstract
RhoA, a member of Rho GTPases, regulates myriad cellular processes. Abnormal expression of RhoA has been implicated in various diseases, including cancers, developmental disorders and bacterial infections. RhoA mutations G14V and Q63L have been reported to constitutively activate RhoA. To figure out the mechanisms, in total, 1.8 μs molecular dynamics (MD) simulations were performed here on RhoAWT and mutants G14V and Q63L in GTP-bound forms, followed by dynamic analysis. Both mutations were found to affect the conformational dynamics of RhoA switch regions, especially switch I, shifting the whole ensemble from the wild type's open inactive state to different active-like states, where T37 and Mg2+ played important roles. In RhoAG14V, both switches underwent thorough state transition, whereas in RhoAQ63L, only switch I was sustained in a much more closed conformation with additional hydrophobic interactions introduced by L63. Moreover, significantly decreased solvent exposure of the GTP-binding site was observed in both mutants with the surrounding hydrophobic regions expanded, which furnished access to water molecules required for hydrolysis more difficult and thereby impaired GTP hydrolysis. These structural and dynamic differences first suggested the potential activation mechanism of RhoAG14V and RhoAQ63L. Together, our findings complemented the understanding of RhoA activation at the atomic level and can be utilized in the development of novel therapies for RhoA-related diseases.
Collapse
|
5
|
Yu Z, Su H, Chen J, Hu G. Deciphering Conformational Changes of the GDP-Bound NRAS Induced by Mutations G13D, Q61R, and C118S through Gaussian Accelerated Molecular Dynamic Simulations. Molecules 2022; 27:5596. [PMID: 36080363 PMCID: PMC9457619 DOI: 10.3390/molecules27175596] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 08/24/2022] [Accepted: 08/25/2022] [Indexed: 11/29/2022] Open
Abstract
The conformational changes in switch domains significantly affect the activity of NRAS. Gaussian-accelerated molecular dynamics (GaMD) simulations of three separate replicas were performed to decipher the effects of G13D, Q16R, and C118S on the conformational transformation of the GDP-bound NRAS. The analyses of root-mean-square fluctuations and dynamics cross-correlation maps indicated that the structural flexibility and motion modes of the switch domains involved in the binding of NRAS to effectors are highly altered by the G13D, Q61R, and C118Smutations. The free energy landscapes (FELs) suggested that mutations induce more energetic states in NRAS than the GDP-bound WT NRAS and lead to high disorder in the switch domains. The FELs also indicated that the different numbers of sodium ions entering the GDP binding regions compensate for the changes in electrostatic environments caused by mutations, especially for G13D. The GDP-residue interactions revealed that the disorder in the switch domains was attributable to the unstable hydrogen bonds between GDP and two residues, V29 and D30. This work is expected to provide information on the energetic basis and dynamics of conformational changes in switch domains that can aid in deeply understanding the target roles of NRAS in anticancer treatment.
Collapse
Affiliation(s)
- Zhiping Yu
- Shandong Key Laboratory of Biophysics, Institute of Biophysics, Dezhou University, Dezhou 253023, China
| | - Hongyi Su
- Laoling People’s Hospital, Dezhou 253600, China
| | - Jianzhong Chen
- School of Science, Shandong Jiaotong University, Jinan 250357, China
| | - Guodong Hu
- Shandong Key Laboratory of Biophysics, Institute of Biophysics, Dezhou University, Dezhou 253023, China
- Laoling People’s Hospital, Dezhou 253600, China
| |
Collapse
|
6
|
Chen J, Zeng Q, Wang W, Hu Q, Bao H. Q61 mutant-mediated dynamics changes of the GTP-KRAS complex probed by Gaussian accelerated molecular dynamics and free energy landscapes. RSC Adv 2022; 12:1742-1757. [PMID: 35425180 PMCID: PMC8978876 DOI: 10.1039/d1ra07936k] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Accepted: 01/04/2022] [Indexed: 12/19/2022] Open
Abstract
Understanding the molecular mechanism of the GTP-KRAS binding is significant for improving the target roles of KRAS in cancer treatment. In this work, multiple replica Gaussian accelerated molecular dynamics (MR-GaMD) simulations were applied to decode the effect of Q61A, Q61H and Q61L on the activity of KRAS. Dynamics analyses based on MR-GaMD trajectory reveal that motion modes and dynamics behavior of the switch domain in KRAS are heavily affected by the three Q61 mutants. Information of free energy landscapes (FELs) shows that Q61A, Q61H and Q61L induce structural disorder of the switch domain and disturb the activity of KRAS. Analysis of the interaction network uncovers that the decrease in the stability of hydrogen bonding interactions (HBIs) of GTP with residues V29 and D30 induced by Q61A, Q61H and Q61L is responsible for the structural disorder of the switch-I and that in the occupancy of the hydrogen bond between GTP and residue G60 leads to the structural disorder of the switch-II. Thus, the high disorder of the switch domain caused by three current Q61 mutants produces a significant effect on binding of KRAS to its effectors. This work is expected to provide useful information for further understanding function and target roles of KRAS in anti-cancer drug development.
Collapse
Affiliation(s)
- Jianzhong Chen
- School of Science, Shandong Jiaotong University Jinan 250357 China
| | - Qingkai Zeng
- School of Science, Shandong Jiaotong University Jinan 250357 China
| | - Wei Wang
- School of Science, Shandong Jiaotong University Jinan 250357 China
| | - Qingquan Hu
- School of Science, Shandong Jiaotong University Jinan 250357 China
| | - Huayin Bao
- School of Pharmacy, Shandong University of Traditional Chinese Medicine Jinan 250355 China
| |
Collapse
|
7
|
Felline A, Raimondi F, Gentile S, Fanelli F. Structural communication between the GTPase Sec4p and its activator Sec2p: Determinants of GEF activity and early deformations to nucleotide release. Comput Struct Biotechnol J 2022; 20:5162-5180. [PMID: 36187918 PMCID: PMC9508438 DOI: 10.1016/j.csbj.2022.09.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 09/08/2022] [Accepted: 09/08/2022] [Indexed: 11/29/2022] Open
Abstract
Ras GTPases are molecular switches that cycle between OFF and ON states depending on the bound nucleotide (i.e. GDP-bound and GTP-bound, respectively). The Rab GTPase, Sec4p, plays regulatory roles in multiple steps of intracellular vesicle trafficking. Nucleotide release is catalyzed by the Guanine Nucleotide Exchange Factor (GEF) Sec2p. Here, the integration of structural information with molecular dynamics (MD) simulations addressed a number of questions concerning the intrinsic and stimulated dynamics of Sec2p and Sec4p as well as the chain of structural deformations leading to GEF-assisted activation of the Rab GTPase. Sec2p holds an intrinsic ability to adopt the conformation found in the crystallographic complexes with Sec4p, thus suggesting that the latter selects and shifts the conformational equilibrium towards a pre-existing bound-like conformation of Sec2p. The anchoring of Sec4p to a suitable conformation of Sec2p favors the Sec2p-assisted pulling on itself of the α1/switch 1 (SWI) loop and of SWI, which loose any contact with GDP. Those deformations of Sec4p would occur earlier. Formation of the final Sec2p-Sec4p hydrophobic interface, accomplishes later. Disruption of the nucleotide cage would cause firstly loss of interactions with the guanine ring and secondly loss of interactions with the phosphates. The ease in sampling the energy landscape and adopting a bound-like conformation likely favors the catalyzing ability of GEFs for Ras GTPases.
Collapse
|
8
|
Zhao J, Wang L, Bao H, Chen J. Cluster analysis on conformational changes of the GDP/KRAS complex induced by A59G and D33E. Chem Phys Lett 2021. [DOI: 10.1016/j.cplett.2021.138995] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
9
|
Chen J, Wang L, Wang W, Sun H, Pang L, Bao H. Conformational transformation of switch domains in GDP/K-Ras induced by G13 mutants: An investigation through Gaussian accelerated molecular dynamics simulations and principal component analysis. Comput Biol Med 2021; 135:104639. [PMID: 34247129 DOI: 10.1016/j.compbiomed.2021.104639] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 07/05/2021] [Accepted: 07/05/2021] [Indexed: 10/20/2022]
Abstract
Mutations in K-Ras are involved in a large number of all human cancers, thus, K-Ras is regarded as a promising target for anticancer drug design. Understanding the target roles of K-Ras is important for providing insights on the molecular mechanism underlying the conformational transformation of the switch domains in K-Ras due to mutations. In this study, multiple replica Gaussian accelerated molecular (MR-GaMD) simulations and principal component analysis (PCA) were applied to probe the effect of G13A, G13D and G13I mutations on conformational transformations of the switch domains in GDP-associated K-Ras. The results suggest that G13A, G13D and G13I enhance the structural flexibility of the switch domains, change the correlated motion modes of the switch domains and strengthen the total motion strength of K-Ras compared with the wild-type (WT) K-Ras. Free energy landscape analyses not only show that the switch domains of the GDP-bound inactive K-Ras mainly exist as a closed state but also indicate that mutations evidently alter the free energy profile of K-Ras and affect the conformational transformation of the switch domains between the closed and open states. Analyses of hydrophobic interaction contacts and hydrogen bonding interactions show that the mutations scarcely change the interaction network of GDP with K-Ras and only disturb the interaction of GDP with the switch (SW1). In summary, two newly introduced mutations, G13A and G13I, play similar adjustment roles in the conformational transformations of two switch domains to G13D and are possibly utilized to tune the activity of K-Ras and the binding of guanine nucleotide exchange factors.
Collapse
Affiliation(s)
- Jianzhong Chen
- School of Science, Shandong Jiaotong University, Jinan, 250357, China.
| | - Lifei Wang
- School of Science, Shandong Jiaotong University, Jinan, 250357, China
| | - Wei Wang
- School of Science, Shandong Jiaotong University, Jinan, 250357, China
| | - Haibo Sun
- School of Science, Shandong Jiaotong University, Jinan, 250357, China
| | - Laixue Pang
- School of Science, Shandong Jiaotong University, Jinan, 250357, China
| | - Huayin Bao
- School of Pharmacy, Shandong University of Traditional Chinese Medicine, Jinan, 250355, China.
| |
Collapse
|
10
|
Chen J, Zhang S, Wang W, Pang L, Zhang Q, Liu X. Mutation-Induced Impacts on the Switch Transformations of the GDP- and GTP-Bound K-Ras: Insights from Multiple Replica Gaussian Accelerated Molecular Dynamics and Free Energy Analysis. J Chem Inf Model 2021; 61:1954-1969. [PMID: 33739090 DOI: 10.1021/acs.jcim.0c01470] [Citation(s) in RCA: 85] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Mutations yield significant effect on the structural flexibility of two switch domains, SW1 and SW2, in K-Ras, which is considered as an important target of anticancer drug design. To unveil a molecular mechanism with regard to mutation-mediated tuning on the activity of K-Ras, multiple replica Gaussian accelerated molecular dynamics (MR-GaMD) simulations followed by analysis of free energy landscapes (FELs) are performed on the GDP- and GTP-bound wild-type (WT), G12V, and D33E K-Ras. The results suggest that G12V and D33E not only evidently change the flexibility of SW1 and SW2 but also greatly affect correlated motions of SW1 and SW2 separately relative to the P-loop and SW1, which exerts a certain tuning on the activity of K-Ras. The information stemming from the analyses of FELs reveals that the conformations of SW1 and SW2 are in high disorders in the GDP- and GTP-associated WT and mutated K-Ras, possibly producing significant effect on binding of guanine nucleotide exchange factors or effectors to K-Ras. The interaction networks of GDP and GTP with K-Ras are identified and the results uncover that the instability in hydrogen-bonding interactions of SW1 with GDP and GTP is mostly responsible for conformational disorder of SW1 and SW2 as well as tunes the activity of oncogenic K-Ras.
Collapse
Affiliation(s)
- Jianzhong Chen
- School of Science, Shandong Jiaotong University, Jinan 250357, China
| | - Shaolong Zhang
- School of Physics and Electronics, Shandong Normal University, Jinan, 250358, China
| | - Wei Wang
- School of Science, Shandong Jiaotong University, Jinan 250357, China
| | - Laixue Pang
- School of Science, Shandong Jiaotong University, Jinan 250357, China
| | - Qinggang Zhang
- School of Physics and Electronics, Shandong Normal University, Jinan, 250358, China
| | - Xinguo Liu
- School of Physics and Electronics, Shandong Normal University, Jinan, 250358, China
| |
Collapse
|
11
|
Dynamic Protein Allosteric Regulation and Disease. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1163:25-43. [DOI: 10.1007/978-981-13-8719-7_2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
|
12
|
Orellana L. Large-Scale Conformational Changes and Protein Function: Breaking the in silico Barrier. Front Mol Biosci 2019; 6:117. [PMID: 31750315 PMCID: PMC6848229 DOI: 10.3389/fmolb.2019.00117] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2019] [Accepted: 10/14/2019] [Indexed: 12/16/2022] Open
Abstract
Large-scale conformational changes are essential to link protein structures with their function at the cell and organism scale, but have been elusive both experimentally and computationally. Over the past few years developments in cryo-electron microscopy and crystallography techniques have started to reveal multiple snapshots of increasingly large and flexible systems, deemed impossible only short time ago. As structural information accumulates, theoretical methods become central to understand how different conformers interconvert to mediate biological function. Here we briefly survey current in silico methods to tackle large conformational changes, reviewing recent examples of cross-validation of experiments and computational predictions, which show how the integration of different scale simulations with biological information is already starting to break the barriers between the in silico, in vitro, and in vivo worlds, shedding new light onto complex biological problems inaccessible so far.
Collapse
Affiliation(s)
- Laura Orellana
- Institutionen för Biokemi och Biofysik, Stockholms Universitet, Stockholm, Sweden.,Science for Life Laboratory, Solna, Sweden
| |
Collapse
|
13
|
Khaled M, Gorfe A, Sayyed-Ahmad A. Conformational and Dynamical Effects of Tyr32 Phosphorylation in K-Ras: Molecular Dynamics Simulation and Markov State Models Analysis. J Phys Chem B 2019; 123:7667-7675. [PMID: 31419909 PMCID: PMC7020251 DOI: 10.1021/acs.jpcb.9b05768] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Phosphorylation of tyrosine 32 in K-Ras has been shown to influence function by disrupting the GTPase cycle. To shed light on the underlying mechanism and atomic basis of this process, we carried out a comparative investigation of the oncogenic G12D K-Ras mutant and its phosphorylated variant (pTyr32) using all-atom molecular dynamics simulations and Markov state models. We show that, despite sharing a number of common features, G12D and pTyr32-G12D K-Ras exhibit some distinct conformational states and fluctuations. In addition to notable differences in conformation and dynamics of residues surrounding the GTP binding site, nonlocal changes were observed at a number of loops. Switch I is more flexible in pTyr32-G12D K-Ras while switch II is more flexible in G12D K-Ras. We also used time-lagged independent component analysis and k-means clustering to identify five metastable states for each system. We utilized transition path theory to calculate the transition probabilities for each state to build a Markov state model for each system. These models and other close inspections suggest that the phosphorylation of Tyr32 strongly affects protein dynamics and the active site conformation, especially with regards to the canonical switch conformations and dynamics.
Collapse
Affiliation(s)
- Mohammed Khaled
- Department of Physics, Birzeit University, PO Box 14, Birzeit, Palestine
| | - Alemayehu Gorfe
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston, 6431 Fannin Street, Houston, Texas 77030, United States
| | | |
Collapse
|
14
|
Lu S, Ni D, Wang C, He X, Lin H, Wang Z, Zhang J. Deactivation Pathway of Ras GTPase Underlies Conformational Substates as Targets for Drug Design. ACS Catal 2019. [DOI: 10.1021/acscatal.9b02556] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Shaoyong Lu
- Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Clinical and Fundamental Research Center, Department of Pharmacy, Renji Hospital, Shanghai Jiao Tong University, School of Medicine, Shanghai 200127, China
| | - Duan Ni
- Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Clinical and Fundamental Research Center, Department of Pharmacy, Renji Hospital, Shanghai Jiao Tong University, School of Medicine, Shanghai 200127, China
| | - Chengxiang Wang
- Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Clinical and Fundamental Research Center, Department of Pharmacy, Renji Hospital, Shanghai Jiao Tong University, School of Medicine, Shanghai 200127, China
| | - Xinheng He
- Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Clinical and Fundamental Research Center, Department of Pharmacy, Renji Hospital, Shanghai Jiao Tong University, School of Medicine, Shanghai 200127, China
| | - Houwen Lin
- Research Center for Marine Drugs, State Key Laboratory of Oncogenes and Related Genes, Department of Pharmacy, Renji Hospital, Shanghai Jiao Tong University, School of Medicine, Shanghai 200127, China
| | - Zheng Wang
- Department of Gastrointestinal Surgery, Renji Hospital, Shanghai Jiao Tong University, School of Medicine, Shanghai 200127, China
| | - Jian Zhang
- Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Clinical and Fundamental Research Center, Department of Pharmacy, Renji Hospital, Shanghai Jiao Tong University, School of Medicine, Shanghai 200127, China
| |
Collapse
|
15
|
Ni D, Li X, He X, Zhang H, Zhang J, Lu S. Drugging K-Ras G12C through covalent inhibitors: Mission possible? Pharmacol Ther 2019; 202:1-17. [PMID: 31233765 DOI: 10.1016/j.pharmthera.2019.06.007] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Ras, whose mutants are present in approximately 30% of human tumours, is one of the most important oncogenes. Drugging Ras is thus regarded as the quest for the Holy Grail in cancer therapeutics development. Despite more than three decades of efforts, drug discovery targeting Ras constantly fails, rendering Ras undruggable, due to its smooth surface and picomolar affinity towards guanosine substrates. The most frequently mutated isoform of Ras is K-Ras, accounting for >85% of Ras-driven cancers, and one majority of them is the G12C mutation. Recent advances in structural biology shed light on drugging Ras, and one of the cutting-edge breakthroughs is the design of covalent G12C-specific inhibitors targeting the mutated cysteine. This type of inhibitor can be classified into substrate-competitive orthosteric inhibitors and non-competitive allosteric inhibitors. They display improved selectivity and enhanced potency due to their G12-specific and irreversible covalent binding nature. Thus, they represent a new hope for revolutionizing the conventional characterization of Ras as "undruggable" and pave a promising avenue for further drug discovery. Here, we provide comprehensive structural and medicinal chemical insights into K-Ras covalent inhibitors specific for the G12C mutant. We first present an in-depth analysis of the conformations of the inhibitor binding pockets. Then, all the latest covalent ligands selectively inhibiting K-RasG12C are reviewed. Finally, we examine the current challenges faced by this new class of anti-Ras inhibitors.
Collapse
Affiliation(s)
- Duan Ni
- Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University, School of Medicine, Shanghai 200025, China
| | - Xinyi Li
- Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University, School of Medicine, Shanghai 200025, China
| | - Xinheng He
- Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University, School of Medicine, Shanghai 200025, China
| | - Hao Zhang
- Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University, School of Medicine, Shanghai 200025, China
| | - Jian Zhang
- Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University, School of Medicine, Shanghai 200025, China; Medicinal Bioinformatics Center, Shanghai Jiao Tong University, School of Medicine, Shanghai 200025, China.
| | - Shaoyong Lu
- Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University, School of Medicine, Shanghai 200025, China; Medicinal Bioinformatics Center, Shanghai Jiao Tong University, School of Medicine, Shanghai 200025, China.
| |
Collapse
|
16
|
Review: Precision medicine and driver mutations: Computational methods, functional assays and conformational principles for interpreting cancer drivers. PLoS Comput Biol 2019; 15:e1006658. [PMID: 30921324 PMCID: PMC6438456 DOI: 10.1371/journal.pcbi.1006658] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
At the root of the so-called precision medicine or precision oncology, which is our focus here, is the hypothesis that cancer treatment would be considerably better if therapies were guided by a tumor’s genomic alterations. This hypothesis has sparked major initiatives focusing on whole-genome and/or exome sequencing, creation of large databases, and developing tools for their statistical analyses—all aspiring to identify actionable alterations, and thus molecular targets, in a patient. At the center of the massive amount of collected sequence data is their interpretations that largely rest on statistical analysis and phenotypic observations. Statistics is vital, because it guides identification of cancer-driving alterations. However, statistics of mutations do not identify a change in protein conformation; therefore, it may not define sufficiently accurate actionable mutations, neglecting those that are rare. Among the many thematic overviews of precision oncology, this review innovates by further comprehensively including precision pharmacology, and within this framework, articulating its protein structural landscape and consequences to cellular signaling pathways. It provides the underlying physicochemical basis, thereby also opening the door to a broader community.
Collapse
|
17
|
Takahara S, Inoue SI, Miyagawa-Tomita S, Matsuura K, Nakashima Y, Niihori T, Matsubara Y, Saiki Y, Aoki Y. New Noonan syndrome model mice with RIT1 mutation exhibit cardiac hypertrophy and susceptibility to β-adrenergic stimulation-induced cardiac fibrosis. EBioMedicine 2019; 42:43-53. [PMID: 30898653 PMCID: PMC6491386 DOI: 10.1016/j.ebiom.2019.03.014] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 02/27/2019] [Accepted: 03/06/2019] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Noonan syndrome (NS) is a genetic disorder characterized by short stature, a distinctive facial appearance, and heart defects. We recently discovered a novel NS gene, RIT1, which is a member of the RAS subfamily of small GTPases. NS patients with RIT1 mutations have a high incidence of hypertrophic cardiomyopathy and edematous phenotype, but the specific role of RIT1 remains unclear. METHODS To investigate how germline RIT1 mutations cause NS, we generated knock-in mice that carried a NS-associated Rit1 A57G mutation (Rit1A57G/+). We investigated the phenotypes of Rit1A57G/+ mice in fetal and adult stages as well as the effects of isoproterenol on cardiac function in Rit1A57G/+ mice. FINDINGS Rit1A57G/+ embryos exhibited decreased viability, edema, subcutaneous hemorrhage and AKT activation. Surviving Rit1A57G/+ mice had a short stature, craniofacial abnormalities and splenomegaly. Cardiac hypertrophy and cardiac fibrosis with increased expression of S100A4, vimentin and periostin were observed in Rit1A57G/+ mice compared to Rit1+/+ mice. Upon isoproterenol stimulation, cardiac fibrosis was drastically increased in Rit1A57G/+ mice. Phosphorylated (at Thr308) AKT levels were also elevated in isoproterenol-treated Rit1A57G/+ hearts. INTERPRETATION The A57G mutation in Rit1 causes cardiac hypertrophy, fibrosis and other NS-associated features. Biochemical analysis indicates that the AKT signaling pathway might be related to downstream signaling in the RIT1 A57G mutant at a developmental stage and under β-adrenergic stimulation in the heart. FUND: The Grants-in-Aid were provided by the Practical Research Project for Rare/Intractable Diseases from the Japan Agency for Medical Research and Development, the Japan Society for the Promotion of Science KAKENHI Grant.
Collapse
Affiliation(s)
- Shingo Takahara
- Department of Medical Genetics, Tohoku University Graduate School of Medicine, Sendai, Japan; Division of Cardiovascular Surgery, Graduate School of Medicine, Tohoku University, Sendai, Japan
| | - Shin-Ichi Inoue
- Department of Medical Genetics, Tohoku University Graduate School of Medicine, Sendai, Japan.
| | - Sachiko Miyagawa-Tomita
- Department of Pediatric Cardiology, Tokyo Women's Medical University, Tokyo, Japan; Department of Physiological Chemistry and Metabolism, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan; Department of Animal Nursing Science, Yamazaki University of Animal Health Technology, Tokyo, Japan
| | - Katsuhisa Matsuura
- Institute of Advanced Biomedical Engineering and Science, Tokyo Women's Medical University, Tokyo, Japan; Department of Cardiology, Tokyo Women's Medical University, Tokyo, Japan
| | - Yasumi Nakashima
- Department of Pediatrics, Seirei Hamamatsu General Hospital, Hamamatsu, Japan
| | - Tetsuya Niihori
- Department of Medical Genetics, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Yoichi Matsubara
- Department of Medical Genetics, Tohoku University Graduate School of Medicine, Sendai, Japan; National Center for Child Health and Development, Tokyo, Japan
| | - Yoshikatsu Saiki
- Division of Cardiovascular Surgery, Graduate School of Medicine, Tohoku University, Sendai, Japan
| | - Yoko Aoki
- Department of Medical Genetics, Tohoku University Graduate School of Medicine, Sendai, Japan.
| |
Collapse
|
18
|
Molnar F, Norris LS, Schulten K. Simulated (Un)Binding of Arachidonic Acid in the Cyclooxygenase site of Prostaglandin H2 Synthase-1. PROGRESS IN REACTION KINETICS AND MECHANISM 2019. [DOI: 10.3184/007967400103165155] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Molecular dynamics simulations with external forces are employed to study the unbinding and binding of arachidonic acid (AA) in the cyclooxygenase (COX) site of prostaglandin H2 synthase-1. Simulations with AA inside the COX binding channel reveal sequences of concerted bond rotations in the fatty acid alkyl chain which obviate the need for gross conformational changes in the protein and substrate during unbinding and binding. The all-cis structure of AA, with double bonds separated by two single bonds, facilitates easy access to the COX channel and correct positioning inside the active site for the COX chemistry to occur. Two derivatives of AA, one with a cis double bond changed to a trans configuration and the other with a double bond reduced to a single bond, are also studied. In both cases the concertedness of bond rotations in the fatty acid chain is diminished and larger forces are required to move the fatty acid inside the COX channel. Important motions of residues near the mouth of the COX channel are found and analyzed. In particular, a conformational “switch” involving Arg83, Glu524 and Arg120 is seen to mediate the movement of the substrate from the membrane to the channel.
Collapse
Affiliation(s)
- Ferenc Molnar
- Beckman Institute, University of Illinois at Urbana-Champaign, 405 North Mathews, Urbana, Illinois 61801
| | - Lawrence S. Norris
- Departments of Biomedical Engineering and Chemistry, Northwestern University, 2145 Sheridan, Evanston, IL 60208, USA
| | - Klaus Schulten
- Beckman Institute, University of Illinois at Urbana-Champaign, 405 North Mathews, Urbana, Illinois 61801
| |
Collapse
|
19
|
Röder K, Joseph JA, Husic BE, Wales DJ. Energy Landscapes for Proteins: From Single Funnels to Multifunctional Systems. ADVANCED THEORY AND SIMULATIONS 2019. [DOI: 10.1002/adts.201800175] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Konstantin Röder
- Department of ChemistryUniversity of CambridgeLensfield Road CB2 1EW Cambridge UK
| | - Jerelle A. Joseph
- Department of ChemistryUniversity of CambridgeLensfield Road CB2 1EW Cambridge UK
| | - Brooke E. Husic
- Department of ChemistryUniversity of CambridgeLensfield Road CB2 1EW Cambridge UK
| | - David J. Wales
- Department of ChemistryUniversity of CambridgeLensfield Road CB2 1EW Cambridge UK
| |
Collapse
|
20
|
Prediction of perturbed proton transfer networks. PLoS One 2018; 13:e0207718. [PMID: 30540792 PMCID: PMC6291078 DOI: 10.1371/journal.pone.0207718] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Accepted: 11/05/2018] [Indexed: 11/19/2022] Open
Abstract
The transfer of protons through proton translocating channels is a complex process, for which direct samplings of different protonation states and side chain conformations in a transition network calculation provide an efficient, bias-free description. In principle, a new transition network calculation is required for every unsampled change in the system of interest, e.g. an unsampled protonation state change, which is associated with significant computational costs. Transition networks void of or including an unsampled change are termed unperturbed or perturbed, respectively. Here, we present a prediction method, which is based on an extensive coarse-graining of the underlying transition networks to speed up the calculations. It uses the minimum spanning tree and a corresponding sensitivity analysis of an unperturbed transition network as initial guess and refinement parameter for the determination of an unknown, perturbed transition network. Thereby, the minimum spanning tree defines a sub-network connecting all nodes without cycles and minimal edge weight sum, while the sensitivity analysis analyzes the stability of the minimum spanning tree towards individual edge weight reductions. Using the prediction method, we are able to reduce the calculation costs in a model system by up to 80%, while important network properties are maintained in most predictions.
Collapse
|
21
|
Hodošček M, Elghobashi-Meinhardt N. Simulations of NPC1(NTD):NPC2 Protein Complex Reveal Cholesterol Transfer Pathways. Int J Mol Sci 2018; 19:ijms19092623. [PMID: 30181526 PMCID: PMC6163316 DOI: 10.3390/ijms19092623] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Revised: 08/30/2018] [Accepted: 08/31/2018] [Indexed: 11/22/2022] Open
Abstract
The Niemann Pick type C (NPC) proteins, NPC1 and NPC2, are involved in the lysosomal storage disease, NPC disease. The formation of a NPC1–NPC2 protein–protein complex is believed to be necessary for the transfer of cholesterol and lipids out of the late endosomal (LE)/lysosomal (Lys) compartments. Mutations in either NPC1 or NPC2 can lead to an accumulation of cholesterol and lipids in the LE/Lys, the primary phenotype of the NPC disease. We investigated the NPC1(NTD)–NPC2 protein–protein complex computationally using two putative binding interfaces. A combination of molecular modeling and molecular dynamics simulations reveals atomic details that are responsible for interface stability. Cholesterol binding energies associated with each of the binding pockets for the two models are calculated. Analyses of the cholesterol binding in the two models support bidirectional ligand transfer when a particular interface is established. Based on the results, we propose that, depending on the location of the cholesterol ligand, a dynamical interface between the NPC2 and NPC1(NTD) proteins exists. Structural features of a particular interface can lower the energy barrier and stabilize the passage of the cholesterol substrate from NPC2 to NPC1(NTD).
Collapse
Affiliation(s)
- Milan Hodošček
- National Institute of Chemistry, Hajdrihova 19, 1001 Ljubljana, Slovenia.
| | | |
Collapse
|
22
|
Röder K, Wales DJ. Predicting Pathways between Distant Configurations for Biomolecules. J Chem Theory Comput 2018; 14:4271-4278. [DOI: 10.1021/acs.jctc.8b00370] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Konstantin Röder
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, U.K
| | - David J. Wales
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, U.K
| |
Collapse
|
23
|
Li Y, Zhang Y, Großerüschkamp F, Stephan S, Cui Q, Kötting C, Xia F, Gerwert K. Specific Substates of Ras To Interact with GAPs and Effectors: Revealed by Theoretical Simulations and FTIR Experiments. J Phys Chem Lett 2018; 9:1312-1317. [PMID: 29488771 PMCID: PMC6692134 DOI: 10.1021/acs.jpclett.8b00342] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The oncogenic Ras protein adopts various specific conformational states to execute its function in signal transduction. The large number of Ras structures obtained from X-ray and NMR experiments illustrates the diverse conformations that Ras adopts. It is difficult, however, to connect specific structural features with Ras functions. We report the free-energy landscape of Ras·GTP based on extensive explicit solvent simulations. The free-energy map clearly shows that the functional state 2 of Ras·GTP in fact has two distinct substates, denoted here as "Tyr32in" and "Tyr32out". Unbiased MD simulations show that the two substrates interconvert on the submicrosecond scale in solution, pointing to a novel mechanism for Ras·GTP to selectively interact with GAPs and effectors. This proposal is further supported by time-resolved FTIR experiments, which demonstrate that Tyr32 destabilizes the Ras·GAP complex and facilitates an efficient termination of Ras signaling.
Collapse
Affiliation(s)
- Yang Li
- School of Chemistry and Molecular Engineering , East China Normal University , Shanghai 200062 , China
- School of Information Science and Engineering , Shandong Agricultural University , Taian 271018 , China
| | - Yuwei Zhang
- School of Chemistry and Molecular Engineering , East China Normal University , Shanghai 200062 , China
| | | | - Sara Stephan
- Department of Biophysics , Ruhr-University Bochum , ND 04 North , 44780 Bochum , Germany
| | - Qiang Cui
- Department of Chemistry and Theoretical Chemistry Institute , University of Wisconsin , 1101 University Avenue , Madison , Wisconsin 53706 , United States
| | - Carsten Kötting
- Department of Biophysics , Ruhr-University Bochum , ND 04 North , 44780 Bochum , Germany
| | - Fei Xia
- School of Chemistry and Molecular Engineering , East China Normal University , Shanghai 200062 , China
- NYU-ECNU Center for Computational Chemistry at NYU Shanghai , Shanghai 200062 , China
| | - Klaus Gerwert
- Department of Biophysics , Ruhr-University Bochum , ND 04 North , 44780 Bochum , Germany
| |
Collapse
|
24
|
Xu S, Long BN, Boris GH, Chen A, Ni S, Kennedy MA. Structural insight into the rearrangement of the switch I region in GTP-bound G12A K-Ras. ACTA CRYSTALLOGRAPHICA SECTION D-STRUCTURAL BIOLOGY 2017; 73:970-984. [PMID: 29199977 DOI: 10.1107/s2059798317015418] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 07/23/2017] [Accepted: 10/23/2017] [Indexed: 12/21/2022]
Abstract
K-Ras, a molecular switch that regulates cell growth, apoptosis and metabolism, is activated when it undergoes a conformation change upon binding GTP and is deactivated following the hydrolysis of GTP to GDP. Hydrolysis of GTP in water is accelerated by coordination to K-Ras, where GTP adopts a high-energy conformation approaching the transition state. The G12A mutation reduces intrinsic K-Ras GTP hydrolysis by an unexplained mechanism. Here, crystal structures of G12A K-Ras in complex with GDP, GTP, GTPγS and GppNHp, and of Q61A K-Ras in complex with GDP, are reported. In the G12A K-Ras-GTP complex, the switch I region undergoes a significant reorganization such that the Tyr32 side chain points towards the GTP-binding pocket and forms a hydrogen bond to the GTP γ-phosphate, effectively stabilizing GTP in its precatalytic state, increasing the activation energy required to reach the transition state and contributing to the reduced intrinsic GTPase activity of G12A K-Ras mutants.
Collapse
Affiliation(s)
- Shenyuan Xu
- Department of Chemistry and Biochemistry, Miami University, Oxford, OH 45056, USA
| | - Brian N Long
- Department of Chemistry and Biochemistry, Miami University, Oxford, OH 45056, USA
| | - Gabriel H Boris
- Department of Chemistry and Biochemistry, Miami University, Oxford, OH 45056, USA
| | - Anqi Chen
- Department of Chemistry and Biochemistry, Miami University, Oxford, OH 45056, USA
| | - Shuisong Ni
- Department of Chemistry and Biochemistry, Miami University, Oxford, OH 45056, USA
| | - Michael A Kennedy
- Department of Chemistry and Biochemistry, Miami University, Oxford, OH 45056, USA
| |
Collapse
|
25
|
Electric-Field-Induced Protein Translocation via a Conformational Transition in SecDF: An MD Study. Biophys J 2017. [PMID: 28636909 DOI: 10.1016/j.bpj.2017.04.034] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
SecDF is an important component of the Sec protein translocation machinery embedded in the bacterial membrane, which is associated with many functions, such as stabilizing other Sec translocon components within the membrane, maintaining the transmembrane (TM) potential, and facilitating the ATP-independent stage of the translocation mechanism. Related studies suggest that SecDF undergoes functionally important conformational changes that involve mainly its P1-head domain and that these changes are coupled with the proton motive force (Δp). However, there still is not a clear understanding of how SecDF functions, its exact role in the translocation machinery, and how its function is related to Δp. Here, using all-atom molecular dynamics simulations combined with umbrella sampling, we study the P1-head conformational change and how it is coupled to the proton motive force. We report potentials of mean force along a root-mean-square-distance-based reaction coordinate obtained in the presence and absence of the TM electrical potential. Our results show that the interaction of the P1 domain dipole moment with the TM electrical field considerably lowers the free-energy barrier in the direction of F-form to I-form transition.
Collapse
|
26
|
Lv D, Gong W, Zhang Y, Liu Y, Li C. A coarse-grained method to predict the open-to-closed behavior of glutamine binding protein. Chem Phys 2017. [DOI: 10.1016/j.chemphys.2017.05.019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
|
27
|
Sharma N, Sonavane U, Joshi R. Differentiating the pre-hydrolysis states of wild-type and A59G mutant HRas: An insight through MD simulations. Comput Biol Chem 2017; 69:96-109. [PMID: 28600956 DOI: 10.1016/j.compbiolchem.2017.05.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Revised: 02/15/2017] [Accepted: 05/26/2017] [Indexed: 01/09/2023]
Abstract
The most representative member of the Ras subfamily is its HRas isoform. Ras proteins being GTPases, possess an intrinsic activity to hydrolyze the GTP molecule to GDP. During the transition phases, between active and inactive states, P-loop and switch regions show maximum variations. Various hot-spot Ras mutants (G12V, A59G, Q61L etc) have been reported, that limit the protein's conformation in the permanent active state. In the present study, we aim to explore the structural dynamics of one such crucial mutant of Ras namely A59G which belongs to the conserved Switch II region of the protein. Approximately ∼15μs of Classical Molecular Dynamics (CMD) simulations have been carried out on the mutant and wild-type complexes. Further, a metadynamics simulation of 500ns was also carried out, which suggests an energy barrier of ∼9.56kcal/mol between wild-type and mutant conformation. We demonstrate the role of water molecule in maintaining the required interaction networks in the pre-hydrolysis state, its impact on A59G mutation, distinct orientation of the Gln61 residue in two conformations, disruption of crucial Gly60 and γ phosphate and the change in the Switch II region. The outcome of our study captures the pre-hydrolysis state of the HRas protein. It also establishes the fact that this mutation makes the movement of Switch II region and the conserved DXXGQ motif highly constrained, which is known to be an important requirement for hydrolysis. This suggests that the A59G mutation may decrease the rate of intrinsic hydrolysis as well as GAP-mediated hydrolysis.
Collapse
Affiliation(s)
- Neeru Sharma
- HPC - Medical and Bioinformatics Applications Group, Centre for Development of Advanced Computing, Pune University Campus, Pune - 411 007, India
| | - Uddhavesh Sonavane
- HPC - Medical and Bioinformatics Applications Group, Centre for Development of Advanced Computing, Pune University Campus, Pune - 411 007, India.
| | - Rajendra Joshi
- HPC - Medical and Bioinformatics Applications Group, Centre for Development of Advanced Computing, Pune University Campus, Pune - 411 007, India.
| |
Collapse
|
28
|
Sayyed-Ahmad A, Prakash P, Gorfe AA. Distinct dynamics and interaction patterns in H- and K-Ras oncogenic P-loop mutants. Proteins 2017; 85:1618-1632. [PMID: 28498561 DOI: 10.1002/prot.25317] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2017] [Revised: 04/27/2017] [Accepted: 05/05/2017] [Indexed: 12/31/2022]
Abstract
Despite years of study, the structural or dynamical basis for the differential reactivity and oncogenicity of Ras isoforms and mutants remains unclear. In this study, we investigated the effects of amino acid variations on the structure and dynamics of wild type and oncogenic mutants G12D, G12V, and G13D of H- and K-Ras proteins. Based on data from µs-scale molecular dynamics simulations, we show that the overall structure of the proteins remains similar but there are important differences in dynamics and interaction networks. We identified differences in residue interaction patterns around the canonical switch and distal loop regions, and persistent sodium ion binding near the GTP particularly in the G13D mutants. Our results also suggest that different Ras variants have distinct local structural features and interactions with the GTP, variations that have the potential to affect GTP release and hydrolysis. Furthermore, we found that H-Ras proteins and particularly the G12V and G13D variants are significantly more flexible than their K-Ras counterparts. Finally, while most of the simulated proteins sampled the effector-interacting state 2 conformational state, G12V and G13D H-Ras adopted an open switch state 1 conformation that is defective in effector interaction. These differences have implications for Ras GTPase activity, effector or exchange factor binding, dimerization and membrane interaction. Proteins 2017; 85:1618-1632. © 2017 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Abdallah Sayyed-Ahmad
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston, Houston, Texas, 77030
| | - Priyanka Prakash
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston, Houston, Texas, 77030
| | - Alemayehu A Gorfe
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston, Houston, Texas, 77030
| |
Collapse
|
29
|
Nucleotide Dependent Switching in Rho GTPase: Conformational Heterogeneity and Competing Molecular Interactions. Sci Rep 2017; 7:45829. [PMID: 28374773 PMCID: PMC5379185 DOI: 10.1038/srep45829] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Accepted: 03/06/2017] [Indexed: 01/05/2023] Open
Abstract
Ras superfamily of GTPases regulate myriad cellular processes through a conserved nucleotide (GTP/GDP) dependent switching mechanism. Unlike Ras family of GTPases, for the Rho GTPases, there is no clear evidence for the existence of “sub-states” such as state 1 & state 2 in the GTP bound form. To explore the nucleotide dependent conformational space of the Switch I loop and also to look for existence of state 1 like conformations in Rho GTPases, atomistic molecular dynamics and metadynamics simulations on RhoA were performed. These studies demonstrate that both the nucleotide-free state and the GDP bound “OFF” state have very similar conformations, whereas the GTP bound “ON” state has unique conformations with signatures of two intermediate states. The conformational free energy landscape for these systems suggests the presence of multiple intermediate states. Interestingly, the energetic penalty of exposing the non-polar residues in the GTP bound form is counter balanced by the favourable hydrogen bonded interactions between the γ-phosphate group of GTP with the highly conserved Tyr34 and Thr37 residues. These competing molecular interactions lead to a tuneable energy landscape of the Switch I conformation, which can undergo significant changes based on the local environment including changes upon binding to effectors.
Collapse
|
30
|
Gao K, Zhao Y. A Network of Conformational Transitions in the Apo Form of NDM-1 Enzyme Revealed by MD Simulation and a Markov State Model. J Phys Chem B 2017; 121:2952-2960. [PMID: 28319394 DOI: 10.1021/acs.jpcb.7b00062] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
New Delhi metallo-β-lactamase-1 (NDM-1) is a novel β-lactamase enzyme that confers enteric bacteria with nearly complete resistance to all β-lactam antibiotics, so it raises a formidable and global threat to human health. However, the binding mechanism between apo-NDM-1 and antibiotics as well as related conformational changes remains poorly understood, which largely hinders the overcoming of its antibiotic resistance. In our study, long-time conventional molecular dynamics simulation and Markov state models were applied to reveal both the dynamical and conformational landscape of apo-NDM-1: the MD simulation demonstrates that loop L3, which is responsible for antibiotic binding, is the most flexible and undergoes dramatic conformational changes; moreover, the Markov state model built from the simulation maps four metastable states including open, semiopen, and closed conformations of loop L3 as well as frequent transitions between the states. Our findings propose a possible conformational selection model for the binding mechanism between apo-NDM-1 and antibiotics, which facilitates the design of novel inhibitors and antibiotics.
Collapse
Affiliation(s)
- Kaifu Gao
- Institute of Biophysics and Department of Physics, Central China Normal University , Wuhan 430079, P. R. China
| | - Yunjie Zhao
- Institute of Biophysics and Department of Physics, Central China Normal University , Wuhan 430079, P. R. China
| |
Collapse
|
31
|
Gao K, Jia Y, Yang M. A Network of Conformational Transitions Revealed by Molecular Dynamics Simulations of the Binary Complex of Escherichia coli 6-Hydroxymethyl-7,8-dihydropterin Pyrophosphokinase with MgATP. Biochemistry 2016; 55:6931-6939. [PMID: 27951655 DOI: 10.1021/acs.biochem.6b00720] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
6-Hydroxymethyl-7,8-dihydropterin pyrophosphokinase (HPPK) catalyzes the first reaction in the folate biosynthetic pathway. Comparison of its X-ray and nuclear magnetic resonance structures suggests that the enzyme undergoes significant conformational change upon binding to its substrates, especially in three catalytic loops. Experimental research has shown that, in its binary form, even bound by analogues of MgATP, loops 2 and 3 remain rather flexible; this raises questions about the putative large-scale induced-fit conformational change of the HPPK-MgATP binary complex. In this work, long-time all-atomic molecular dynamics simulations were conducted to investigate the loop dynamics in this complex. Our simulations show that, with loop 3 closed, multiple conformations of loop 2, including the open, semiopen, and closed forms, are all accessible to the binary complex. These results provide valuable structural insights into the details of conformational changes upon 6-hydroxymethyl-7,8-dihydropterin (HP) binding and biological activities of HPPK. Conformational network analysis and principal component analysis related to the loops are also discussed.
Collapse
Affiliation(s)
- Kaifu Gao
- Institute of Biophysics and Department of Physics, Central China Normal University , Wuhan 430079, P. R. China
| | - Ya Jia
- Institute of Biophysics and Department of Physics, Central China Normal University , Wuhan 430079, P. R. China
| | - Minghui Yang
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Centre for Magnetic Resonance, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences , Wuhan 430071, P. R. China
| |
Collapse
|
32
|
Lu S, Jang H, Gu S, Zhang J, Nussinov R. Drugging Ras GTPase: a comprehensive mechanistic and signaling structural view. Chem Soc Rev 2016; 45:4929-52. [PMID: 27396271 PMCID: PMC5021603 DOI: 10.1039/c5cs00911a] [Citation(s) in RCA: 142] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Ras proteins are small GTPases, cycling between inactive GDP-bound and active GTP-bound states. Through these switches they regulate signaling that controls cell growth and proliferation. Activating Ras mutations are associated with approximately 30% of human cancers, which are frequently resistant to standard therapies. Over the past few years, structural biology and in silico drug design, coupled with improved screening technology, led to a handful of promising inhibitors, raising the possibility of drugging Ras proteins. At the same time, the invariable emergence of drug resistance argues for the critical importance of additionally honing in on signaling pathways which are likely to be involved. Here we overview current advances in Ras structural knowledge, including the conformational dynamic of full-length Ras in solution and at the membrane, therapeutic inhibition of Ras activity by targeting its active site, allosteric sites, and Ras-effector protein-protein interfaces, Ras dimers, the K-Ras4B/calmodulin/PI3Kα trimer, and targeting Ras with siRNA. To mitigate drug resistance, we propose signaling pathways that can be co-targeted along with Ras and explain why. These include pathways leading to the expression (or activation) of YAP1 and c-Myc. We postulate that these and Ras signaling pathways, MAPK/ERK and PI3K/Akt/mTOR, act independently and in corresponding ways in cell cycle control. The structural data are instrumental in the discovery and development of Ras inhibitors for treating RAS-driven cancers. Together with the signaling blueprints through which drug resistance can evolve, this review provides a comprehensive and innovative master plan for tackling mutant Ras proteins.
Collapse
Affiliation(s)
- Shaoyong Lu
- Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Children’s Medical Center, Shanghai Jiao Tong University, School of Medicine, Shanghai, 200127, China
| | - Hyunbum Jang
- Cancer and Inflammation Program, Leidos Biomedical Research, Inc., Frederick National Laboratory, National Cancer Institute, Frederick, MD 21702, U.S.A
| | - Shuo Gu
- Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Children’s Medical Center, Shanghai Jiao Tong University, School of Medicine, Shanghai, 200127, China
| | - Jian Zhang
- Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Children’s Medical Center, Shanghai Jiao Tong University, School of Medicine, Shanghai, 200127, China
| | - Ruth Nussinov
- Cancer and Inflammation Program, Leidos Biomedical Research, Inc., Frederick National Laboratory, National Cancer Institute, Frederick, MD 21702, U.S.A
- Department of Human Genetics and Molecular Medicine, Sackler School of Medicine, Sackler Institute of Molecular Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| |
Collapse
|
33
|
Maximova T, Moffatt R, Ma B, Nussinov R, Shehu A. Principles and Overview of Sampling Methods for Modeling Macromolecular Structure and Dynamics. PLoS Comput Biol 2016; 12:e1004619. [PMID: 27124275 PMCID: PMC4849799 DOI: 10.1371/journal.pcbi.1004619] [Citation(s) in RCA: 132] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Investigation of macromolecular structure and dynamics is fundamental to understanding how macromolecules carry out their functions in the cell. Significant advances have been made toward this end in silico, with a growing number of computational methods proposed yearly to study and simulate various aspects of macromolecular structure and dynamics. This review aims to provide an overview of recent advances, focusing primarily on methods proposed for exploring the structure space of macromolecules in isolation and in assemblies for the purpose of characterizing equilibrium structure and dynamics. In addition to surveying recent applications that showcase current capabilities of computational methods, this review highlights state-of-the-art algorithmic techniques proposed to overcome challenges posed in silico by the disparate spatial and time scales accessed by dynamic macromolecules. This review is not meant to be exhaustive, as such an endeavor is impossible, but rather aims to balance breadth and depth of strategies for modeling macromolecular structure and dynamics for a broad audience of novices and experts.
Collapse
Affiliation(s)
- Tatiana Maximova
- Department of Computer Science, George Mason University, Fairfax, Virginia, United States of America
| | - Ryan Moffatt
- Department of Computer Science, George Mason University, Fairfax, Virginia, United States of America
| | - Buyong Ma
- Basic Science Program, Leidos Biomedical Research, Inc. Cancer and Inflammation Program, National Cancer Institute, Frederick, Maryland, United States of America
| | - Ruth Nussinov
- Basic Science Program, Leidos Biomedical Research, Inc. Cancer and Inflammation Program, National Cancer Institute, Frederick, Maryland, United States of America
- Sackler Institute of Molecular Medicine, Department of Human Genetics and Molecular Medicine, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Amarda Shehu
- Department of Computer Science, George Mason University, Fairfax, Virginia, United States of America
- Department of Biongineering, George Mason University, Fairfax, Virginia, United States of America
- School of Systems Biology, George Mason University, Manassas, Virginia, United States of America
| |
Collapse
|
34
|
Lu S, Jang H, Nussinov R, Zhang J. The Structural Basis of Oncogenic Mutations G12, G13 and Q61 in Small GTPase K-Ras4B. Sci Rep 2016; 6:21949. [PMID: 26902995 PMCID: PMC4763299 DOI: 10.1038/srep21949] [Citation(s) in RCA: 135] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Accepted: 02/04/2016] [Indexed: 02/08/2023] Open
Abstract
Ras mediates cell proliferation, survival and differentiation. Mutations in K-Ras4B are predominant at residues G12, G13 and Q61. Even though all impair GAP-assisted GTP → GDP hydrolysis, the mutation frequencies of K-Ras4B in human cancers vary. Here we aim to figure out their mechanisms and differential oncogenicity. In total, we performed 6.4 μs molecular dynamics simulations on the wild-type K-Ras4B (K-Ras4B(WT)-GTP/GDP) catalytic domain, the K-Ras4B(WT)-GTP-GAP complex, and the mutants (K-Ras4B(G12C/G12D/G12V)-GTP/GDP, K-Ras4B(G13D)-GTP/GDP, K-Ras4B(Q61H)-GTP/GDP) and their complexes with GAP. In addition, we simulated 'exchanged' nucleotide states. These comprehensive simulations reveal that in solution K-Ras4B(WT)-GTP exists in two, active and inactive, conformations. Oncogenic mutations differentially elicit an inactive-to-active conformational transition in K-Ras4B-GTP; in K-Ras4B(G12C/G12D)-GDP they expose the bound nucleotide which facilitates the GDP-to-GTP exchange. These mechanisms may help elucidate the differential mutational statistics in K-Ras4B-driven cancers. Exchanged nucleotide simulations reveal that the conformational transition is more accessible in the GTP-to-GDP than in the GDP-to-GTP exchange. Importantly, GAP not only donates its R789 arginine finger, but stabilizes the catalytically-competent conformation and pre-organizes catalytic residue Q61; mutations disturb the R789/Q61 organization, impairing GAP-mediated GTP hydrolysis. Together, our simulations help provide a mechanistic explanation of key mutational events in one of the most oncogenic proteins in cancer.
Collapse
Affiliation(s)
- Shaoyong Lu
- Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University, School of Medicine, Shanghai, 200025, China
- Cancer and Inflammation Program, Leidos Biomedical Research, Inc., Frederick National Laboratory, National Cancer Institute, Frederick, MD 21702, USA
| | - Hyunbum Jang
- Cancer and Inflammation Program, Leidos Biomedical Research, Inc., Frederick National Laboratory, National Cancer Institute, Frederick, MD 21702, USA
| | - Ruth Nussinov
- Cancer and Inflammation Program, Leidos Biomedical Research, Inc., Frederick National Laboratory, National Cancer Institute, Frederick, MD 21702, USA
- Department of Human Genetics and Molecular Medicine, Sackler School of Medicine, Sackler Institute of Molecular Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Jian Zhang
- Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University, School of Medicine, Shanghai, 200025, China
- Institute of Bioinformatics and Medical Engineering, School of Electrical and Information Engineering, Jiangsu University of Technology, Changzhou 213001, China
| |
Collapse
|
35
|
Lu S, Jang H, Muratcioglu S, Gursoy A, Keskin O, Nussinov R, Zhang J. Ras Conformational Ensembles, Allostery, and Signaling. Chem Rev 2016; 116:6607-65. [PMID: 26815308 DOI: 10.1021/acs.chemrev.5b00542] [Citation(s) in RCA: 266] [Impact Index Per Article: 33.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Ras proteins are classical members of small GTPases that function as molecular switches by alternating between inactive GDP-bound and active GTP-bound states. Ras activation is regulated by guanine nucleotide exchange factors that catalyze the exchange of GDP by GTP, and inactivation is terminated by GTPase-activating proteins that accelerate the intrinsic GTP hydrolysis rate by orders of magnitude. In this review, we focus on data that have accumulated over the past few years pertaining to the conformational ensembles and the allosteric regulation of Ras proteins and their interpretation from our conformational landscape standpoint. The Ras ensemble embodies all states, including the ligand-bound conformations, the activated (or inactivated) allosteric modulated states, post-translationally modified states, mutational states, transition states, and nonfunctional states serving as a reservoir for emerging functions. The ensemble is shifted by distinct mutational events, cofactors, post-translational modifications, and different membrane compositions. A better understanding of Ras biology can contribute to therapeutic strategies.
Collapse
Affiliation(s)
- Shaoyong Lu
- Department of Pathophysiology, Shanghai Universities E-Institute for Chemical Biology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University, School of Medicine , Shanghai, 200025, China.,Cancer and Inflammation Program, Leidos Biomedical Research, Inc., Frederick National Laboratory, National Cancer Institute , Frederick, Maryland 21702, United States
| | - Hyunbum Jang
- Cancer and Inflammation Program, Leidos Biomedical Research, Inc., Frederick National Laboratory, National Cancer Institute , Frederick, Maryland 21702, United States
| | | | | | | | - Ruth Nussinov
- Cancer and Inflammation Program, Leidos Biomedical Research, Inc., Frederick National Laboratory, National Cancer Institute , Frederick, Maryland 21702, United States.,Department of Human Genetics and Molecular Medicine, Sackler School of Medicine, Sackler Institute of Molecular Medicine, Tel Aviv University , Tel Aviv 69978, Israel
| | - Jian Zhang
- Department of Pathophysiology, Shanghai Universities E-Institute for Chemical Biology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University, School of Medicine , Shanghai, 200025, China
| |
Collapse
|
36
|
Abstract
SUMMARYEvidence is emerging that the role of protein structure in disease needs to be rethought. Sequence mutations in proteins are often found to affect the rate at which a protein switches between structures. Modeling structural transitions in wildtype and variant proteins is central to understanding the molecular basis of disease. This paper investigates an efficient algorithmic realization of the stochastic roadmap simulation framework to model structural transitions in wildtype and variants of proteins implicated in human disorders. Our results indicate that the algorithm is able to extract useful information on the impact of mutations on protein structure and function.
Collapse
|
37
|
Gao K, He H, Yang M, Yan H. Molecular dynamics simulations of the Escherichia coli HPPK apo-enzyme reveal a network of conformational transitions. Biochemistry 2015; 54:6734-42. [PMID: 26492157 DOI: 10.1021/acs.biochem.5b01012] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
6-Hydroxymethyl-7,8-dihydropterin pyrophosphokinase (HPPK) catalyzes the first reaction in the folate biosynthetic pathway. Comparison of its X-ray and nuclear magnetic resonance structures suggests that the enzyme undergoes significant conformational change upon binding to its substrates, especially in three catalytic loops. Experimental research has shown that even when confined by crystal contacts, loops 2 and 3 remain rather flexible when the enzyme is in its apo form, raising questions about the putative large-scale induced-fit conformational change of HPPK. To investigate the loop dynamics in a crystal-free environment, we performed conventional molecular dynamics simulations of the apo-enzyme at two different temperatures (300 and 350 K). Our simulations show that the crystallographic B-factors considerably underestimate the loop dynamics; multiple conformations of loops 2 and 3, including the open, semi-open, and closed conformations that an enzyme must adopt throughout its catalytic cycle, are all accessible to the apo-enzyme. These results revise our previous view of the functional mechanism of conformational change upon MgATP binding and offer valuable structural insights into the workings of HPPK. In this paper, conformational network analysis and principal component analysis related to the loops are discussed to support the presented conclusions.
Collapse
Affiliation(s)
- Kaifu Gao
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences , Wuhan 430071, P. R. China
| | - Hongqing He
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences , Wuhan 430071, P. R. China
| | - Minghui Yang
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences , Wuhan 430071, P. R. China
| | - Honggao Yan
- Department of Biochemistry and Molecular Biology, Michigan State University , East Lansing, Michigan 48824, United States
| |
Collapse
|
38
|
Clausen R, Ma B, Nussinov R, Shehu A. Mapping the Conformation Space of Wildtype and Mutant H-Ras with a Memetic, Cellular, and Multiscale Evolutionary Algorithm. PLoS Comput Biol 2015; 11:e1004470. [PMID: 26325505 PMCID: PMC4556523 DOI: 10.1371/journal.pcbi.1004470] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Accepted: 07/28/2015] [Indexed: 11/18/2022] Open
Abstract
An important goal in molecular biology is to understand functional changes upon single-point mutations in proteins. Doing so through a detailed characterization of structure spaces and underlying energy landscapes is desirable but continues to challenge methods based on Molecular Dynamics. In this paper we propose a novel algorithm, SIfTER, which is based instead on stochastic optimization to circumvent the computational challenge of exploring the breadth of a protein's structure space. SIfTER is a data-driven evolutionary algorithm, leveraging experimentally-available structures of wildtype and variant sequences of a protein to define a reduced search space from where to efficiently draw samples corresponding to novel structures not directly observed in the wet laboratory. The main advantage of SIfTER is its ability to rapidly generate conformational ensembles, thus allowing mapping and juxtaposing landscapes of variant sequences and relating observed differences to functional changes. We apply SIfTER to variant sequences of the H-Ras catalytic domain, due to the prominent role of the Ras protein in signaling pathways that control cell proliferation, its well-studied conformational switching, and abundance of documented mutations in several human tumors. Many Ras mutations are oncogenic, but detailed energy landscapes have not been reported until now. Analysis of SIfTER-computed energy landscapes for the wildtype and two oncogenic variants, G12V and Q61L, suggests that these mutations cause constitutive activation through two different mechanisms. G12V directly affects binding specificity while leaving the energy landscape largely unchanged, whereas Q61L has pronounced, starker effects on the landscape. An implementation of SIfTER is made available at http://www.cs.gmu.edu/~ashehu/?q=OurTools. We believe SIfTER is useful to the community to answer the question of how sequence mutations affect the function of a protein, when there is an abundance of experimental structures that can be exploited to reconstruct an energy landscape that would be computationally impractical to do via Molecular Dynamics.
Collapse
Affiliation(s)
- Rudy Clausen
- Department of Computer Science, George Mason University, Fairfax, Virginia, United States of America
| | - Buyong Ma
- Basic Science Program, Leidos Biomedical Research, Inc. Cancer and Inflammation Program, National Cancer Institute, Frederick, Maryland, United States of America
| | - Ruth Nussinov
- Basic Science Program, Leidos Biomedical Research, Inc. Cancer and Inflammation Program, National Cancer Institute, Frederick, Maryland, United States of America
- Sackler Institute of Molecular Medicine, Department of Human Genetics and Molecular Medicine, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Amarda Shehu
- Department of Computer Science, George Mason University, Fairfax, Virginia, United States of America
- Department of Biongineering, George Mason University, Fairfax, Virginia, United States of America
- School of Systems Biology, George Mason University, Manassas, Virginia, United States of America
| |
Collapse
|
39
|
Kapoor A, Travesset A. Differential dynamics of RAS isoforms in GDP- and GTP-bound states. Proteins 2015; 83:1091-106. [PMID: 25846136 DOI: 10.1002/prot.24805] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Revised: 03/12/2015] [Accepted: 03/20/2015] [Indexed: 11/10/2022]
Abstract
RAS subfamily proteins regulates cell growth promoting signaling processes by cycling between active (GTP-bound) and inactive (GDP-bound) states. Different RAS isoforms, though structurally similar, exhibit functional specificity and are associated with different types of cancers and developmental disorders. Understanding the dynamical differences between the isoforms is crucial for the design of inhibitors that can selectively target a particular malfunctioning isoform. In this study, we provide a comprehensive comparison of the dynamics of all the three RAS isoforms (HRAS, KRAS, and NRAS) using extensive molecular dynamics simulations in both the GDP- (total of 3.06 μs) and GTP-bound (total of 2.4 μs) states. We observed significant differences in the dynamics of the isoforms, which rather interestingly, varied depending on the type of the nucleotide bound and the simulation temperature. Both SwitchI (Residues 25-40) and SwitchII (Residues 59-75) differ significantly in their flexibility in the three isoforms. Furthermore, Principal Component Analysis showed that there are differences in the conformational space sampled by the GTP-bound RAS isoforms. We also identified a previously unreported pocket, which opens transiently during MD simulations, and can be targeted to regulate nucleotide exchange reaction or possibly interfere with membrane localization. Further, we present the first simulation study showing GDP destabilization in the wild-type RAS protein. The destabilization of GDP/GTP occurred only in 1/50 simulations, emphasizing the need of guanine nucleotide exchange factors (GEFs) to accelerate such an extremely unfavorable process. This observation along with the other results presented in this article further support our previously hypothesized mechanism of GEF-assisted nucleotide exchange.
Collapse
Affiliation(s)
- Abhijeet Kapoor
- Department of Physics and Astronomy, Iowa State University, Ames, Iowa, 50011
| | - Alex Travesset
- Department of Physics and Astronomy, Iowa State University, Ames, Iowa, 50011
| |
Collapse
|
40
|
Wang B, Weng J, Wang W. Substrate binding accelerates the conformational transitions and substrate dissociation in multidrug efflux transporter AcrB. Front Microbiol 2015; 6:302. [PMID: 25918513 PMCID: PMC4394701 DOI: 10.3389/fmicb.2015.00302] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Accepted: 03/27/2015] [Indexed: 11/25/2022] Open
Abstract
The tripartite efflux pump assembly AcrAB-TolC is the major multidrug resistance transporter in E. coli. The inner membrane transporter AcrB is a homotrimer, energized by the proton movement down the transmembrane electrochemical gradient. The asymmetric crystal structures of AcrB with three monomers in distinct conformational states [access (A), binding (B) and extrusion (E)] support a functional rotating mechanism, in which each monomer of AcrB cycles among the three states in a concerted way. However, the relationship between the conformational changes during functional rotation and drug translocation has not been totally understood. Here, we explored the conformational changes of the AcrB homotrimer during the ABE to BEA transition in different substrate-binding states using targeted MD simulations. It was found that the dissociation of substrate from the distal binding pocket of B monomer is closely related to the concerted conformational changes in the translocation pathway, especially the side chain reorientation of Phe628 and Tyr327. A second substrate binding at the proximal binding pocket of A monomer evidently accelerates the conformational transitions as well as substrate dissociation in B monomer. The acceleration effect of the multi-substrate binding mode provides a molecular explanation for the positive cooperativity observed in the kinetic studies of substrate efflux and deepens our understanding of the functional rotating mechanism of AcrB.
Collapse
Affiliation(s)
- Beibei Wang
- Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Department of Chemistry, Fudan University Shanghai, China
| | - Jingwei Weng
- Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Department of Chemistry, Fudan University Shanghai, China
| | - Wenning Wang
- Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Department of Chemistry, Fudan University Shanghai, China ; Institutes of Biomedical Sciences, Fudan University Shanghai, China
| |
Collapse
|
41
|
Mhlongo NN, Soliman MES. Single H5N1 influenza A neuraminidase mutation develops resistance to oseltamivir due to distorted conformational and drug binding landscape: multiple molecular dynamics analyses. RSC Adv 2015. [DOI: 10.1039/c4ra13494j] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Clinical studies showed that a single mutation, I117V, develops severe resistance to oseltamivir, the first orally active influenza A neuraminidase inhibitor, in highly pathogenic H5N1 influenza A viruses.
Collapse
Affiliation(s)
- Ndumiso N. Mhlongo
- Molecular Modelling and Drug Design Research Group
- School of Health Sciences
- University of KwaZulu-Natal
- Durban 4001
- South Africa
| | - Mahmoud E. S. Soliman
- Molecular Modelling and Drug Design Research Group
- School of Health Sciences
- University of KwaZulu-Natal
- Durban 4001
- South Africa
| |
Collapse
|
42
|
Xiao X, Zeng X, Yuan Y, Gao N, Guo Y, Pu X, Li M. Understanding the conformation transition in the activation pathway of β2 adrenergic receptor via a targeted molecular dynamics simulation. Phys Chem Chem Phys 2015; 17:2512-22. [DOI: 10.1039/c4cp04528a] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The conformation transition in the activation pathway of β2 adrenergic receptor was explored mainly using a target molecular dynamics simulation.
Collapse
Affiliation(s)
- Xiuchan Xiao
- Faculty of Chemistry
- Sichuan University
- Chengdu
- People's Republic of China
| | - Xiaojun Zeng
- Faculty of Chemistry
- Sichuan University
- Chengdu
- People's Republic of China
| | - Yuan Yuan
- College of Management
- Southwest University for Nationalities
- Chengdu
- People's Republic of China
| | - Nan Gao
- Faculty of Chemistry
- Sichuan University
- Chengdu
- People's Republic of China
| | - Yanzhi Guo
- Faculty of Chemistry
- Sichuan University
- Chengdu
- People's Republic of China
| | - Xuemei Pu
- Faculty of Chemistry
- Sichuan University
- Chengdu
- People's Republic of China
| | - Menglong Li
- Faculty of Chemistry
- Sichuan University
- Chengdu
- People's Republic of China
| |
Collapse
|
43
|
Li XY, Xie F, Zhang JC, Su JG. Study, by use of coarse-grained models, of the functionally crucial residues and allosteric pathway of anesthetic regulation of the Gloeobacter violaceus ligand-gated ion channel. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2014; 43:623-30. [PMID: 25367560 DOI: 10.1007/s00249-014-0992-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Revised: 07/24/2014] [Accepted: 10/01/2014] [Indexed: 11/28/2022]
Abstract
Although pentameric ligand-gated ion channels (pLGICs) have been found to be the targets of general anesthetics, the mechanism of the effects of anesthetics on pLGICs remains elusive. pLGICs from Gloeobacter violaceus (GLIC) can be inhibited by the anesthetic ketamine. X-ray crystallography has shown that the ketamine binding site is distant from the channel gate of the GLIC. It is still not clear how ketamine controls the function of the GLIC by long-range allosteric regulation. In this work, the functionally crucial residues and allosteric pathway of anesthetic regulation of the GLIC were identified by use of a coarse-grained thermodynamic method developed by our group. In our method, the functionally crucial sites were identified as the residues thermodynamically coupled with binding of ketamine. The results from calculation were highly consistent with experimental data. Our study aids understanding of the mechanism of the anesthetic action of ketamine on the GLIC by long-range allosteric modulation.
Collapse
Affiliation(s)
- Xing Yuan Li
- College of Science, Yanshan University, Qinhuangdao, 066004, China
| | | | | | | |
Collapse
|
44
|
Kapoor A, Travesset A. Mechanism of the exchange reaction in HRAS from multiscale modeling. PLoS One 2014; 9:e108846. [PMID: 25272152 PMCID: PMC4182752 DOI: 10.1371/journal.pone.0108846] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2014] [Accepted: 08/28/2014] [Indexed: 11/28/2022] Open
Abstract
HRAS regulates cell growth promoting signaling processes by cycling between active (GTP-bound) and inactive (GDP-bound) states. Understanding the transition mechanism is central for the design of small molecules to inhibit the formation of RAS-driven tumors. Using a multiscale approach involving coarse-grained (CG) simulations, all-atom classical molecular dynamics (CMD; total of 3.02 µs), and steered molecular dynamics (SMD) in combination with Principal Component Analysis (PCA), we identified the structural features that determine the nucleotide (GDP) exchange reaction. We show that weakening the coupling between the SwitchI (residues 25–40) and SwitchII (residues 59–75) accelerates the opening of SwitchI; however, an open conformation of SwitchI is unstable in the absence of guanine nucleotide exchange factors (GEFs) and rises up towards the bound nucleotide to close the nucleotide pocket. Both I21 and Y32, play a crucial role in SwitchI transition. We show that an open SwitchI conformation is not necessary for GDP destabilization but is required for GDP/Mg escape from the HRAS. Further, we present the first simulation study showing displacement of GDP/Mg away from the nucleotide pocket. Both SwitchI and SwitchII, delays the escape of displaced GDP/Mg in the absence of GEF. Based on these results, a model for the mechanism of GEF in accelerating the exchange process is hypothesized.
Collapse
Affiliation(s)
- Abhijeet Kapoor
- Physics and Astronomy, Iowa State University, Ames, Iowa, United States of America
- * E-mail:
| | - Alex Travesset
- Physics and Astronomy, Iowa State University, Ames, Iowa, United States of America
| |
Collapse
|
45
|
Src promotes GTPase activity of Ras via tyrosine 32 phosphorylation. Proc Natl Acad Sci U S A 2014; 111:E3785-94. [PMID: 25157176 DOI: 10.1073/pnas.1406559111] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Mutations in Ras GTPase and various other components of the Ras signaling pathways are among the most common genetic alterations in human cancers and also have been identified in several familial developmental syndromes. Over the past few decades it has become clear that the activity or the oncogenic potential of Ras is dependent on the nonreceptor tyrosine kinase Src to promote the Ras/Raf/MAPK pathway essential for proliferation, differentiation, and survival of eukaryotic cells. However, no direct relationship between Ras and Src has been established. We show here that Src binds to and phosphorylates GTP-, but not GDP-, loaded Ras on a conserved Y32 residue within the switch I region in vitro and that in vivo, Ras-Y32 phosphorylation markedly reduces the binding to effector Raf and concomitantly increases binding to GTPase-activating proteins and the rate of GTP hydrolysis. These results suggest that, in the context of predetermined crystallographic structures, Ras-Y32 serves as an Src-dependent keystone regulatory residue that modulates Ras GTPase activity and ensures unidirectionality to the Ras GTPase cycle.
Collapse
|
46
|
Flex E, Jaiswal M, Pantaleoni F, Martinelli S, Strullu M, Fansa EK, Caye A, De Luca A, Lepri F, Dvorsky R, Pannone L, Paolacci S, Zhang SC, Fodale V, Bocchinfuso G, Rossi C, Burkitt-Wright EMM, Farrotti A, Stellacci E, Cecchetti S, Ferese R, Bottero L, Castro S, Fenneteau O, Brethon B, Sanchez M, Roberts AE, Yntema HG, Van Der Burgt I, Cianci P, Bondeson ML, Cristina Digilio M, Zampino G, Kerr B, Aoki Y, Loh ML, Palleschi A, Di Schiavi E, Carè A, Selicorni A, Dallapiccola B, Cirstea IC, Stella L, Zenker M, Gelb BD, Cavé H, Ahmadian MR, Tartaglia M. Activating mutations in RRAS underlie a phenotype within the RASopathy spectrum and contribute to leukaemogenesis. Hum Mol Genet 2014; 23:4315-27. [PMID: 24705357 PMCID: PMC4103678 DOI: 10.1093/hmg/ddu148] [Citation(s) in RCA: 105] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Accepted: 03/04/2014] [Indexed: 12/29/2022] Open
Abstract
RASopathies, a family of disorders characterized by cardiac defects, defective growth, facial dysmorphism, variable cognitive deficits and predisposition to certain malignancies, are caused by constitutional dysregulation of RAS signalling predominantly through the RAF/MEK/ERK (MAPK) cascade. We report on two germline mutations (p.Gly39dup and p.Val55Met) in RRAS, a gene encoding a small monomeric GTPase controlling cell adhesion, spreading and migration, underlying a rare (2 subjects among 504 individuals analysed) and variable phenotype with features partially overlapping Noonan syndrome, the most common RASopathy. We also identified somatic RRAS mutations (p.Gly39dup and p.Gln87Leu) in 2 of 110 cases of non-syndromic juvenile myelomonocytic leukaemia, a childhood myeloproliferative/myelodysplastic disease caused by upregulated RAS signalling, defining an atypical form of this haematological disorder rapidly progressing to acute myeloid leukaemia. Two of the three identified mutations affected known oncogenic hotspots of RAS genes and conferred variably enhanced RRAS function and stimulus-dependent MAPK activation. Expression of an RRAS mutant homolog in Caenorhabditis elegans enhanced RAS signalling and engendered protruding vulva, a phenotype previously linked to the RASopathy-causing SHOC2(S2G) mutant. Overall, these findings provide evidence of a functional link between RRAS and MAPK signalling and reveal an unpredicted role of enhanced RRAS function in human disease.
Collapse
Affiliation(s)
- Elisabetta Flex
- Dipartimento di Ematologia, Oncologia e Medicina Molecolare and
| | - Mamta Jaiswal
- Institut für Biochemie und Molekularbiologie II, Medizinische Fakultät der Heinrich-Heine Universitat, Düsseldorf 40225, Germany
| | | | | | - Marion Strullu
- Genetics Department, INSERM UMR_S940, Institut Universitaire D'Hématologie (IUH), Université Paris-Diderot Sorbonne-Paris-Cité, Paris 75010, France
| | - Eyad K Fansa
- Institut für Biochemie und Molekularbiologie II, Medizinische Fakultät der Heinrich-Heine Universitat, Düsseldorf 40225, Germany
| | - Aurélie Caye
- Genetics Department, INSERM UMR_S940, Institut Universitaire D'Hématologie (IUH), Université Paris-Diderot Sorbonne-Paris-Cité, Paris 75010, France
| | - Alessandro De Luca
- Laboratorio Mendel, Istituto di Ricovero e Cura a Carattere Scientifico-Casa Sollievo Della Sofferenza, Rome 00198, Italy
| | | | - Radovan Dvorsky
- Institut für Biochemie und Molekularbiologie II, Medizinische Fakultät der Heinrich-Heine Universitat, Düsseldorf 40225, Germany
| | - Luca Pannone
- Dipartimento di Ematologia, Oncologia e Medicina Molecolare and
| | | | - Si-Cai Zhang
- Institut für Biochemie und Molekularbiologie II, Medizinische Fakultät der Heinrich-Heine Universitat, Düsseldorf 40225, Germany
| | | | - Gianfranco Bocchinfuso
- Dipartimento di Scienze e Tecnologie Chimiche, Università 'Tor Vergata', Rome 00133, Italy
| | - Cesare Rossi
- UO Genetica Medica, Policlinico S.Orsola-Malpighi, Bologna 40138, Italy
| | - Emma M M Burkitt-Wright
- Genetic Medicine, Academic Health Science Centre, Central Manchester University Hospitals NHS Foundation Trust, Manchester M13 9WL, UK
| | - Andrea Farrotti
- Dipartimento di Scienze e Tecnologie Chimiche, Università 'Tor Vergata', Rome 00133, Italy
| | | | - Serena Cecchetti
- Dipartimento di Biologia Cellulare e Neuroscienze, Istituto Superiore di Sanità, Rome 00161, Italy
| | - Rosangela Ferese
- Laboratorio Mendel, Istituto di Ricovero e Cura a Carattere Scientifico-Casa Sollievo Della Sofferenza, Rome 00198, Italy
| | | | - Silvana Castro
- Istituto di Genetica e Biofisica 'A. Buzzati Traverso', Consiglio Nazionale Delle Ricerche, Naples 80131, Italy
| | | | - Benoît Brethon
- Pediatric Hematology Department, Robert Debré Hospital, Paris 75019, France
| | - Massimo Sanchez
- Dipartimento di Biologia Cellulare e Neuroscienze, Istituto Superiore di Sanità, Rome 00161, Italy
| | - Amy E Roberts
- Department of Cardiology and Division of Genetics, and Department of Medicine, Boston Children's Hospital, Boston, MA 02115, USA
| | - Helger G Yntema
- Department of Human Genetics, Radboud University Medical Centre, and Nijmegen Centre for Molecular Life Sciences, Radboud University, Nijmegen 6500, The Netherlands
| | - Ineke Van Der Burgt
- Department of Human Genetics, Radboud University Medical Centre, and Nijmegen Centre for Molecular Life Sciences, Radboud University, Nijmegen 6500, The Netherlands
| | - Paola Cianci
- Genetica Clinica Pediatrica, Clinica Pediatrica Università Milano Bicocca, Fondazione MBBM, A.O. S. Gerardo, Monza 20900, Italy
| | - Marie-Louise Bondeson
- Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala 75237, Sweden
| | | | - Giuseppe Zampino
- Istituto di Clinica Pediatrica, Università Cattolica del Sacro Cuore, Rome 00168, Italy
| | - Bronwyn Kerr
- Genetic Medicine, Academic Health Science Centre, Central Manchester University Hospitals NHS Foundation Trust, Manchester M13 9WL, UK
| | - Yoko Aoki
- Department of Medical Genetics, Tohoku University School of Medicine, Sendai 980-8574, Japan
| | - Mignon L Loh
- Department of Pediatrics, Benioff Children's Hospital, University of California School of Medicine, and the Helen Diller Family Comprehensive Cancer Center, San Francisco, CA, 94143, USA
| | - Antonio Palleschi
- Dipartimento di Scienze e Tecnologie Chimiche, Università 'Tor Vergata', Rome 00133, Italy
| | - Elia Di Schiavi
- Istituto di Genetica e Biofisica 'A. Buzzati Traverso', Consiglio Nazionale Delle Ricerche, Naples 80131, Italy
| | - Alessandra Carè
- Dipartimento di Ematologia, Oncologia e Medicina Molecolare and
| | - Angelo Selicorni
- Genetica Clinica Pediatrica, Clinica Pediatrica Università Milano Bicocca, Fondazione MBBM, A.O. S. Gerardo, Monza 20900, Italy
| | | | - Ion C Cirstea
- Institut für Biochemie und Molekularbiologie II, Medizinische Fakultät der Heinrich-Heine Universitat, Düsseldorf 40225, Germany, Leibniz Institute for Age Research, Jena 07745, Germany
| | - Lorenzo Stella
- Dipartimento di Scienze e Tecnologie Chimiche, Università 'Tor Vergata', Rome 00133, Italy
| | - Martin Zenker
- Institute of Human Genetics, University Hospital of Magdeburg, Otto-von-Guericke-University, Magdeburg 39120, Germany
| | - Bruce D Gelb
- Department of Pediatrics and Department of Genetics and Department of Genomic Sciences, Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Hélène Cavé
- Genetics Department, INSERM UMR_S940, Institut Universitaire D'Hématologie (IUH), Université Paris-Diderot Sorbonne-Paris-Cité, Paris 75010, France
| | - Mohammad R Ahmadian
- Institut für Biochemie und Molekularbiologie II, Medizinische Fakultät der Heinrich-Heine Universitat, Düsseldorf 40225, Germany
| | - Marco Tartaglia
- Dipartimento di Ematologia, Oncologia e Medicina Molecolare and
| |
Collapse
|
47
|
Gur M, Madura JD, Bahar I. Global transitions of proteins explored by a multiscale hybrid methodology: application to adenylate kinase. Biophys J 2014; 105:1643-52. [PMID: 24094405 DOI: 10.1016/j.bpj.2013.07.058] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2013] [Revised: 06/25/2013] [Accepted: 07/11/2013] [Indexed: 12/19/2022] Open
Abstract
Efficient and accurate mapping of transition pathways is a challenging problem in allosteric proteins. We propose here a to our knowledge new methodology called collective molecular dynamics (coMD). coMD takes advantage of the collective modes of motions encoded by the fold, simultaneously evaluating the interactions and energetics via a full-atomic MD simulation protocol. The basic approach is to deform the structure collectively along the modes predicted by the anisotropic network model, upon selecting them via a Monte Carlo/Metropolis algorithm from among the complete pool of all accessible modes. Application to adenylate kinase, an allosteric enzyme composed of three domains, CORE, LID, and NMP, shows that both open-to-closed and closed-to-open transitions are readily sampled by coMD, with large-scale motions of the LID dominating. An energy-barrier crossing occurs during the NMP movements. The energy barrier originates from a switch between the salt bridges K136-D118 at the LID-CORE interface and K57-E170 and D33-R156 at the CORE-NMP and LID-NMP interfaces, respectively. Despite its simplicity and computing efficiency, coMD yields ensembles of transition pathways in close accord with detailed full atomic simulations, lending support to its utility as a multiscale hybrid method for efficiently exploring the allosteric transitions of multidomain or multimeric proteins.
Collapse
Affiliation(s)
- Mert Gur
- Department of Computational and Systems Biology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | | | | |
Collapse
|
48
|
Probing the wild-type HRas activation mechanism using steered molecular dynamics, understanding the energy barrier and role of water in the activation. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2014; 43:81-95. [PMID: 24442446 DOI: 10.1007/s00249-014-0942-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2013] [Revised: 12/31/2013] [Accepted: 01/02/2014] [Indexed: 10/25/2022]
Abstract
Ras is one of the most common oncogenes in human cancers. It belongs to a family of GTPases that functions as binary conformational switches by timely switching of their conformations from GDP to GTP and vice versa. It attains the final active state structure via an intermediate GTP-bound state. The transition between these states is a millisecond-time-scale event. This makes studying this mechanism beyond the scope of classical molecular dynamics. In the present study, we describe the activation pathway of the HRas protein complex along the distance-based reaction coordinate using steered molecular dynamics. Approximately ~720 ns of MD simulations using CMD and SMD was performed. We demonstrated the change in orientation and arrangement of the two switch regions and the role of various hydrogen bonds during the activation process. The weighted histogram analysis method was also performed, and the potential of mean force was calculated between the inactive and active via the intermediate state (state 1) of HRas. The study indicates that water seems to play a crucial role in the activation process and to transfer the HRas protein from its intermediate state to the fully active state. The implications of our study hereby suggest that the HRas activation mechanism is a multistep process. It starts from the inactive state to an intermediate state 1 followed by trapping of water molecules and flipping of the Thr35 residue to form a fully active state (state 2). This state 2 also comprises Gly60, Thr35, GTP, Mg(2+) and water-forming stable interactions.
Collapse
|
49
|
Gao Y, Iancu CV, Mukind S, Choe JY, Honzatko RB. Mechanism of displacement of a catalytically essential loop from the active site of mammalian fructose-1,6-bisphosphatase. Biochemistry 2013; 52:5206-16. [PMID: 23844654 PMCID: PMC4869526 DOI: 10.1021/bi400532n] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
AMP triggers a 15° subunit-pair rotation in fructose-1,6-bisphosphatase (FBPase) from its active R state to its inactive T state. During this transition, a catalytically essential loop (residues 50-72) leaves its active (engaged) conformation. Here, the structures of Ile(10) → Asp FBPase and molecular dynamic simulations reveal factors responsible for loop displacement. The AMP/Mg(2+) and AMP/Zn(2+) complexes of Asp(10) FBPase are in intermediate quaternary conformations (completing 12° of the subunit-pair rotation), but the complex with Zn(2+) provides the first instance of an engaged loop in a near-T quaternary state. The 12° subunit-pair rotation generates close contacts involving the hinges (residues 50-57) and hairpin turns (residues 58-72) of the engaged loops. Additional subunit-pair rotation toward the T state would make such contacts unfavorable, presumably causing displacement of the loop. Targeted molecular dynamics simulations reveal no steric barriers to subunit-pair rotations of up to 14° followed by the displacement of the loop from the active site. Principal component analysis reveals high-amplitude motions that exacerbate steric clashes of engaged loops in the near-T state. The results of the simulations and crystal structures are in agreement: subunit-pair rotations just short of the canonical T state coupled with high-amplitude modes sterically displace the dynamic loop from the active site.
Collapse
Affiliation(s)
- Yang Gao
- Department of Biochemistry, Biophysics, and Molecular Biology, 4206 Molecular Biology Building, Iowa State University, Ames, Iowa 50011-3260, United States
| | | | | | | | - Richard B. Honzatko
- Department of Biochemistry, Biophysics, and Molecular Biology, 4206 Molecular Biology Building, Iowa State University, Ames, Iowa 50011-3260, United States
| |
Collapse
|
50
|
Prakash P, Gorfe AA. Lessons from computer simulations of Ras proteins in solution and in membrane. Biochim Biophys Acta Gen Subj 2013; 1830:5211-8. [PMID: 23906604 DOI: 10.1016/j.bbagen.2013.07.024] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2013] [Revised: 07/23/2013] [Accepted: 07/24/2013] [Indexed: 12/22/2022]
Abstract
BACKGROUND A great deal has been learned over the last several decades about the function of Ras proteins in solution and membrane environments. While much of this knowledge has been derived from a plethora of experimental techniques, computer simulations have also played a substantial role. SCOPE OF REVIEW Our goal here is to summarize the contribution of molecular simulations to our current understanding of normal and aberrant Ras function. We focus on lessons from molecular dynamics simulations in aqueous and membrane environments. MAJOR CONCLUSIONS The central message is that a close interaction between theory and simulation on the one hand and cell-biological, spectroscopic and other experimental approaches on the other has played, and will likely continue to play, a vital role in Ras research. GENERAL SIGNIFICANCE Atomistic insights emerging from detailed simulations of Ras in solution and in bilayers may be the key to unlock the secret that to date prevented development of selective anti-Ras inhibitors for cancer therapy.
Collapse
Affiliation(s)
- Priyanka Prakash
- University of Texas Health Science Center at Houston, Department of Integrative Biology and Pharmacology, 6431 Fannin St., Houston, TX 77030, USA
| | | |
Collapse
|