scholarly journals Molecular Dynamics Simulations Reveal Isoform Specific Contact Dynamics between the Plexin Rho GTPase Binding Domain (RBD) and Small Rho GTPases Rac1 and Rnd1

2017 ◽  
Vol 121 (7) ◽  
pp. 1485-1498 ◽  
Author(s):  
Liqun Zhang ◽  
Matthias Buck
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Rho Gtpases ◽  
Rho Gtpase ◽  
Binding Domain ◽  
Contact Dynamics ◽  
Specific Contact ◽  
Small Rho Gtpases ◽  
Gtpase Binding Domain ◽  
Dynamics Simulations

scholarly journals Molecular modelling of the nucleotide-binding domain of Wilson's disease protein: location of the ATP-binding site, domain dynamics and potential effects of the major disease mutations

2004 ◽  
Vol 382 (1) ◽  
pp. 293-305 ◽  
Author(s):  
Roman G. EFREMOV ◽  
Yuri A. KOSINSKY ◽  
Dmitry E. NOLDE ◽  
Ruslan TSIVKOVSKII ◽  
Alexander S. ARSENIEV ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Molecular Modelling ◽  
Wilson’S Disease ◽  
Wilson's Disease ◽  
Binding Domain ◽  
Atp Binding ◽  
Disease Mutations ◽  
Disease Protein ◽  
Dynamics Simulations

WNDP (Wilson's disease protein) is a copper-transporting ATPase that plays an essential role in human physiology. Mutations in WNDP result in copper accumulation in tissues and cause a severe hepato-neurological disorder known as Wilson's disease. Several mutations were surmised to affect the nucleotide binding and hydrolysis by WNDP; however, how the nucleotides bind to normal and mutated WNDP remains unknown. To aid such studies, we performed the molecular modelling of the spatial structure and dynamics of the ATP-binding domain of WNDP and its interactions with ATP. The three-dimensional models of this domain in two conformations were built using the X-ray structures of the Ca2+-ATPase in the E1 and E2 states. To study the functional aspects of the models, they were subjected to long-term molecular dynamics simulations in an explicit solvent; similar calculations were performed for the ATP-binding domain of Ca2+-ATPase. In both cases, we found large-scale motions that lead to significant changes of distances between several functionally important residues. The ATP docking revealed two possible modes of ATP binding: via adenosine buried in the cleft near residues H1069, R1151 and D1164, and via phosphate moiety ‘anchored’ by H-bonds with residues in the vicinity of catalytic D1027. Furthermore, interaction of ATP with both sites occurs if they are spatially close to each other. This may be achieved after relative domain motions of the ‘closure’ type observed in molecular dynamics simulations. The results provide a framework for analysis of disease mutations and for future mutagenesis studies.

scholarly journals The flexibility of ACE2 in the context of SARS-CoV-2 infection

2020 ◽  
Author(s):  
E. P. Barros ◽  
L. Casalino ◽  
Z. Gaieb ◽  
A. C. Dommer ◽  
Y. Wang ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Receptor Binding ◽  
Rational Design ◽  
Binding Domain ◽  
Full Length ◽  
Receptor Binding Domain ◽  
Spike Glycoprotein ◽  
Linker Region ◽  
Dynamics Simulations

AbstractThe COVID-19 pandemic has swept over the world in the past months, causing significant loss of life and consequences to human health. Although numerous drug and vaccine developments efforts are underway, many questions remain outstanding on the mechanism of SARS-CoV-2 viral association to angiotensin-converting enzyme 2 (ACE2), its main host receptor, and entry in the cell. Structural and biophysical studies indicate some degree of flexibility in the viral extracellular Spike glycoprotein and at the receptor binding domain-receptor interface, suggesting a role in infection. Here, we perform all-atom molecular dynamics simulations of the glycosylated, full-length membrane-bound ACE2 receptor, in both an apo and spike receptor binding domain (RBD) bound state, in order to probe the intrinsic dynamics of the ACE2 receptor in the context of the cell surface. A large degree of fluctuation in the full length structure is observed, indicating hinge bending motions at the linker region connecting the head to the transmembrane helix, while still not disrupting the ACE2 homodimer or ACE2-RBD interfaces. This flexibility translates into an ensemble of ACE2 homodimer conformations that could sterically accommodate binding of the spike trimer to more than one ACE2 homodimer, and suggests a mechanical contribution of the host receptor towards the large spike conformational changes required for cell fusion. This work presents further structural and functional insights into the role of ACE2 in viral infection that can be exploited for the rational design of effective SARS-CoV-2 therapeutics.Statement of SignificanceAs the host receptor of SARS-CoV-2, ACE2 has been the subject of extensive structural and antibody design efforts in aims to curtail COVID-19 spread. Here, we perform molecular dynamics simulations of the homodimer ACE2 full-length structure to study the dynamics of this protein in the context of the cellular membrane. The simulations evidence exceptional plasticity in the protein structure due to flexible hinge motions in the head-transmembrane domain linker region and helix mobility in the membrane, resulting in a varied ensemble of conformations distinct from the experimental structures. Our findings suggest a dynamical contribution of ACE2 to the spike glycoprotein shedding required for infection, and contribute to the question of stoichiometry of the Spike-ACE2 complex.

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