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Bacterial nucleoid structure probed by active drag and resistive pulse sensing.

TitleBacterial nucleoid structure probed by active drag and resistive pulse sensing.
Publication TypeJournal Article
Year of Publication2014
AuthorsThacker, VV, Bromek, K, Meijer, B, Kotar, J, Sclavi, B, Cosentino Lagomarsino, M, Keyser, UF, Cicuta, P
JournalIntegr Biol (Camb)
Volume6
Issue2
Pagination184-91
Date Published2014 Feb
ISSN1757-9708
Abstract

Recent biophysical approaches have provided key insights into the enthalpic and entropic forces that compact the nucleoid in the cell. Our biophysical approach combines two complementary, non-invasive and label-free techniques: a precisely timed steerable optical trap and a high throughput microcapillary Coulter counter. We demonstrate the ability of the latter technique to probe the physical properties and size of many purified nucleoids, at the individual nucleoid level. The DNA-binding protein H-NS is central to the organization of the bacterial genome. Our results show that nucleoids purified from the Δhns strain in the stationary phase expand approximately five fold more than the form observed in WT bacteria. This compaction is consistent with the role played by H-NS in regulating the nucleoid structure and the significant organizational changes that occur as the cell adapts to the stationary phase. We also study the permeability to the flow of ions and find that in the experiment nucleoids behave as solid colloids.

DOI10.1039/c3ib40147b
Alternate JournalIntegr Biol (Camb)
PubMed ID24321999