HU multimerization shift controls nucleoid compaction

摘要: Molecular mechanisms controlling functional bacterial chromosome (nucleoid) compaction and organization are surprisingly enigmatic but partly depend on conserved, histone-like proteins HUαα HUαβ their interactions that span the nanoscale mesoscale from protein-DNA complexes to nucleoid structure. We determined crystal structures of these chromosome-associated in complex with native duplex DNA. Distinct DNA binding modes elucidate fundamental features packing regulate gene transcription. By combining solution x-ray scattering results, we architectures HU-DNA nucleoproteins under near-physiological conditions. These macromolecular conformations result contraction at cellular level based vivo imaging unlabeled by soft tomography upon HUβ ectopic HUα38 expression. Structural characterization charge-altered HUαα-DNA reveals an HU molecular switch is suitable for condensing reprogramming noninvasive Escherichia coli into invasive form. Collective findings suggest shifts between networking cooperative noncooperative DNA-dependent multimerization control supercoiling independently topoisomerase activity. integrating structures, scattering, mutational tests, structure, show defined dynamic interaction networks can promote reorganization transcriptional regulation as efficient general microbial help synchronize genetic responses cell cycle, changing environments, pathogenesis.