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G Protein-selective GPCR Conformations Measured Using FRET Sensors in a Live Cell Suspension Fluorometer Assay
Published on: September 10, 2016
Conformational selection in G-proteins: lessons from Ras and Rho
Biophysical Journal
|November 30, 2010
Summary
Monomeric G-proteins like Ras and Rho utilize conformational selection, not induced fit, to bind nucleotides. Simulations reveal these proteins naturally explore multiple states, with nucleotide binding selecting the active conformation.
Area of Science:
- Molecular biology
- Biochemistry
- Computational biophysics
Background:
- Monomeric G-proteins (Ras, Rho) traditionally modeled with induced fit for activation.
- Nucleotide presence/absence dictates conformational state instantaneously.
- Limited understanding of intrinsic protein dynamics without ligands.
Discussion:
- Atomistic simulations reveal Ras and Rho proteins intrinsically sample multiple conformations without nucleotide ligands.
- Conformational selection, not induced fit, is the primary mechanism for nucleotide-dependent conformational changes.
- This challenges the traditional induced fit model for these G-proteins.
Key Insights:
- Ras and Rho proteins exhibit inherent conformational flexibility.
- Nucleotide binding acts as a selection mechanism among pre-existing states.
- Correlated motions predict conserved allosteric coupling between nucleotide site and C-terminus.
Outlook:
- Further experimental validation of conformational selection mechanism.
- Investigating other G-protein families for similar dynamics.
- Exploring therapeutic strategies targeting protein dynamics.
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