scholarly journals Molecular Dynamics Simulations and Dynamic Network Analysis Reveal the Allosteric Unbinding of Monobody to H-Ras Triggered by R135K Mutation

2017 ◽  
Vol 18 (11) ◽  
pp. 2249 ◽  
Author(s):  
Duan Ni ◽  
Kun Song ◽  
Jian Zhang ◽  
Shaoyong Lu
2014 ◽  
Vol 169 ◽  
pp. 303-321 ◽  
Author(s):  
Ariane Allain ◽  
Isaure Chauvot de Beauchêne ◽  
Florent Langenfeld ◽  
Yann Guarracino ◽  
Elodie Laine ◽  
...  

Allostery is a universal phenomenon that couples the information induced by a local perturbation (effector) in a protein to spatially distant regulated sites. Such an event can be described in terms of a large scale transmission of information (communication) through a dynamic coupling between structurally rigid (minimally frustrated) and plastic (locally frustrated) clusters of residues. To elaborate a rational description of allosteric coupling, we propose an original approach – MOdular NETwork Analysis (MONETA) – based on the analysis of inter-residue dynamical correlations to localize the propagation of both structural and dynamical effects of a perturbation throughout a protein structure. MONETA uses inter-residue cross-correlations and commute times computed from molecular dynamics simulations and a topological description of a protein to build a modular network representation composed of clusters of residues (dynamic segments) linked together by chains of residues (communication pathways). MONETA provides a brand new direct and simple visualization of protein allosteric communication. A GEPHI module implemented in the MONETA package allows the generation of 2D graphs of the communication network. An interactive PyMOL plugin permits drawing of the communication pathways between chosen protein fragments or residues on a 3D representation. MONETA is a powerful tool for on-the-fly display of communication networks in proteins. We applied MONETA for the analysis of communication pathways (i) between the main regulatory fragments of receptors tyrosine kinases (RTKs), KIT and CSF-1R, in the native and mutated states and (ii) in proteins STAT5 (STAT5a and STAT5b) in the phosphorylated and the unphosphorylated forms. The description of the physical support for allosteric coupling by MONETA allowed a comparison of the mechanisms of (a) constitutive activation induced by equivalent mutations in two RTKs and (b) allosteric regulation in the activated and non-activated STAT5 proteins. Our theoretical prediction based on results obtained with MONETA was validated for KIT by in vitro experiments. MONETA is a versatile analytical and visualization tool entirely devoted to the understanding of the functioning/malfunctioning of allosteric regulation in proteins – a crucial basis to guide the discovery of next-generation allosteric drugs.


2019 ◽  
Author(s):  
Juan A. Bueren-Calabuig ◽  
Marcus Bage ◽  
Victoria H. Cowling ◽  
Andrei V. Pisliakov

ABSTRACTThe RNA guanine-7 methyltransferase (RNMT) in complex with RNMT-Activating Miniprotein (RAM) catalyses the formation of a N7-methylated guanosine cap structure on the 5’ end of nascent RNA polymerase II transcripts. The mRNA cap protects the transcript from exonucleases and recruits cap-binding complexes that mediate RNA processing, export and translation. By using microsecond standard and accelerated molecular dynamics simulations, we provide for the first time a detailed molecular mechanism of allosteric regulation of RNMT by RAM. We show that RAM selects the RNMT active site conformations that are optimal for binding of substrates (AdoMet and the cap), thus enhancing their affinity. Furthermore, our results strongly suggest the likely scenario in which the cap binding promotes the subsequent AdoMet binding, consistent with the previously suggested cooperative binding model. By employing the dynamic network and community analyses, we revealed the underlying long-range allosteric networks and paths that are crucial for allosteric regulation by RAM. Our findings complement and explain previous experimental data on RNMT activity. Moreover, this study provides the most complete description of the cap and AdoMet binding poses and interactions within the enzyme’s active site. This information is critical for the drug discovery efforts that consider RNMT as a promising anti-cancer target.


2020 ◽  
Vol 22 (5) ◽  
pp. 2887-2907
Author(s):  
Trevor R. Fisher ◽  
Guobing Zhou ◽  
Yijun Shi ◽  
Liangliang Huang

Molecular dynamics simulations reveal that the maximum contribution of H-bonds between water and glycerol occurs around 30 mol% glycerol. Such a concentration is also where several of the mixture's properties have an observed maxima or minima.


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