Interactions between DNA and the Hfq Amyloid-like Region Trigger a Viscoelastic Response

Omar El Hamoui (1) , Indresh Yadav (2) , Milad Radiom (3) , Frank Wien (1) , Jean-Francois Berret (3) , Johan R C van Der Maarel (2) , Véronique Arluison (4)

1 SSOLEIL - Synchrotron SOLEIL
2 NUS - National University of Singapore
3 MSC - Matière et Systèmes Complexes
4 MMB - LLB - Matière molle et biophysique

Molecular transport of biomolecules plays a pivotal role in the machinery of life. Yet, this role is poorly understood due the lack of quantitative information. Here, the role and properties of the C-terminal region of Escherichia coli Hfq is reported, involved in controlling the flow of a DNA solution. A combination of experimental methodologies has been used to probe the interaction of Hfq with DNA and to measure the rheological properties of the complex. A physical gel with a temperature reversible elasticity modulus is formed due to formation of non-covalent crosslinks. The mechanical response of the complexes shows that they are inhomogeneous soft solids. Our experiments indicate that Hfq C-terminal region could contribute to genome's mechanical response. The reported viscoelasticity of the DNA-protein complex might have implications for cellular processes involving molecular transport of DNA or segments thereof.

Mots clés: Nucleoid-associated protein (NAP); phase separation; DNA elastic gel; Hfq; functionnal amyloid

Domaines: Matière Molle [cond-mat.soft]; Biomécanique [physics.med-ph]

Omar El Hamoui, Indresh Yadav, Milad Radiom, Frank Wien, Jean-Francois Berret, et al.. Interactions between DNA and the Hfq Amyloid-like Region Trigger a Viscoelastic Response. Biomacromolecules, In press, ⟨10.1021/acs.biomac.0c00747⟩. ⟨hal-02926069⟩