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bioRxiv · 10.1101/2022.06.23.497280

Nucleoid-Associated Proteins Undergo Liquid-Liquid Phase Separation with DNA into Multiphasic Condensates Resembling Bacterial Nucleoids

Gupta, A.·Joshi, A.·Arora, K.·Mukhopadhyay, S.·Guptasarma, P.
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Abstract

Liquid-liquid phase separation offers unique spatiotemporal control over myriad complex intracellular biochemical processes through compartmentalization of biomolecules into highly dynamic, liquid-like condensates known as membrane-less organelles. The bacterial nucleoid is thought to be one such phase-separated condensate; however, its formation, regulation, and biophysical characteristics are poorly understood. Our super-resolution imaging data suggests that nucleoids are dynamic assemblages of sub-micron-sized liquid-like droplets. We demonstrate that non-sequence-specific Nucleoid-Associated Proteins (NAPs) such as HU-A, HU-B and Dps, accrete nucleic acids and spontaneously condense with them into liquid-like, multicomponent, multiphasic, heterotypic phase-separated droplets. Upon mixing of HU-B, DNA and Dps, HU-B-enriched droplets are seen to contain demixed Dps-enriched droplets. Our findings indicate scope for the possible existence of multiphasic liquid-like compartments within nucleoids, providing insights into bacterial growth phase-dependent variations in the levels of different NAPs.

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Gupta, A., Joshi, A., Arora, K., Mukhopadhyay, S., Guptasarma, P.. 2022-06-24. Nucleoid-Associated Proteins Undergo Liquid-Liquid Phase Separation with DNA into Multiphasic Condensates Resembling Bacterial Nucleoids. https://doi.org/10.1101/2022.06.23.497280

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