Equilibrium Dynamics of a Biomolecular Complex Analyzed at Single-amino Acid Resolution by Cryo-electron Microscopy. Issue 8 (15th April 2023)

• Record Type: Journal Article
• Authors: Luque, Daniel; Ortega-Esteban, Alvaro; Valbuena, Alejandro; Luis Vilas, Jose; Rodríguez-Huete, Alicia; Mateu, Mauricio G.; Castón, José R.
• Is Part Of: Journal of molecular biology. Volume 435:Issue 8(2023)
• Publication Date: 2023-04-15
• Subjects: Virus capsid -- Equilibrium dynamics -- Mechanical elasticity -- Cryo-electron microscopy -- Atomic force microscopy; Molecular biology -- Periodicals; Biology -- Periodicals; Biochemistry -- Periodicals; Bacteriology -- Periodicals; Molecular Biology -- Periodicals; Biochemistry -- Periodicals; Biologie moléculaire -- Périodiques; Biologie -- Périodiques; Biochimie -- Périodiques; Moleculaire biologie; Biochemistry; Biology; Molecular biology; Periodicals; 572.805
• DOI: 10.1016/j.jmb.2023.168024
• Languages: English
• ISSNs: 0022-2836

Abstract

Graphical abstract: Cryo-EM structure of the capsid protein of minute virus of mice (MVM): local resolution is a signature of equilibrium dinamics in solution Highlights: Cryo-EM of biocomplexes shows information on their local equilibrium dynamics. Mechanical stiffening and impaired equilibrium dynamics of a virus particle are linked. Abstract: The biological function of macromolecular complexes depends not only on large-scale transitions between conformations, but also on small-scale conformational fluctuations at equilibrium. Information on the equilibrium dynamics of biomolecular complexes could, in principle, be obtained from local resolution (LR) data in cryo-electron microscopy (cryo-EM) maps. However, this possibility had not been validated by comparing, for a same biomolecular complex, LR data with quantitative information on equilibrium dynamics obtained by an established solution technique. In this study we determined the cryo-EM structure of the minute virus of mice (MVM) capsid as a model biomolecular complex. The LR values obtained correlated with crystallographic B factors and with hydrogen/deuterium exchange (HDX) rates obtained by mass spectrometry (HDX-MS), a gold standard for determining equilibrium dynamics in solution. This result validated a LR-based cryo-EM approach to investigate, with high spatial resolution, the equilibrium dynamics of biomolecular complexes. As an application of this approach, we determined the cryo-EM structure of two mutant MVM capsids and compared their equilibrium dynamics with that of the wild-type MVM capsid. The results supported a previously suggested linkage between mechanical stiffening and impaired equilibrium dynamics of a virus particle. Cryo-EM is emerging as a powerful approach for simultaneously acquiring information on the atomic structure and local equilibrium dynamics of biomolecular complexes.