Compaction and condensation of DNA mediated by the C-terminal domain of Hfq

Compaction et condensation de l’ADN induites par le domaine C-terminal amyloïde de Hfq

Antoine Malabirade (1, 2) , Kai Jiang (3) , Krzysztof Kubiak (1) , Alvaro Diaz-Mendoza (4) , Fan Liu (3) , Jeroen A. Van kan (3) , Jean-François Berret (4) , Véronique Arluison (1, 5) , Johan r.C. Van der maarel (3)

1 LLB - UMR 12 - Laboratoire Léon Brillouin
2 UP11 - Université Paris-Sud - Paris 11
3 Department of Physics (Singapore)
4 MSC - Matière et Systèmes Complexes
5 UPD7 - Université Paris Diderot - Paris 7

Hfq is a bacterial protein that is involved in several aspects of nucleic acids metabolism. It has been described as one of the nucleoid associated proteins shaping the bacterial chromosome, although it is better known to influence translation and turnover of cellular RNAs. Here, we explore the role of Escherichia coli Hfq's C-terminal domain in the compaction of double stranded DNA. Various experimental methodologies, including fluorescence microscopy imaging of single DNA molecules confined inside nanofluidic channels, atomic force microscopy, isothermal titration microcalorimetry and electrophoretic mobility assays have been used to follow the assembly of the C-terminal and N-terminal regions of Hfq on DNA. Results highlight the role of Hfq's C-terminal arms in DNA binding, change in mechanical properties of the double helix and compaction of DNA into a condensed form. The propensity for bridging and compaction of DNA by the C-terminal domain might be related to aggregation of bound protein and may have implications for protein binding related gene regulation.

Domains: Biochemistry, Molecular Biology; Molecular biology; Biophysics; Structural Biology [q-bio.BM]

Antoine Malabirade, Kai Jiang, Krzysztof Kubiak, Alvaro Diaz-Mendoza, Fan Liu, et al.. Compaction and condensation of DNA mediated by the C-terminal domain of Hfq. Nucleic Acids Research, 2017, 45, pp.7299 - 7308. ⟨10.1093/nar/gkx431⟩. ⟨cea-01591370⟩