1. Charged residues in the H-NS linker drive DNA binding and gene silencing in single cells.
- Author
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Yunfeng Gao, Yong Hwee Foo, Winardhi, Ricksen S., Qingnan Tang, Jie Yan, and Kenney, Linda J.
- Subjects
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DNA , *CELLS , *DEOXYRIBOSE , *BIOLOGY , *AMINO acids - Abstract
Nucleoid-associated proteins (NAPs) facilitate chromosome organization in bacteria, but the precise mechanism remains elusive. H-NS is a NAP that also plays a major role in silencing pathogen genes. We used genetics, single-particle tracking in live cells, superresolution microscopy, atomic force microscopy, and molecular dynamics simulations to examine H-NS/DNA interactions in single cells. We discovered a role for the unstructured linker region connecting the N-terminal oligomerization and C-terminal DNA binding domains. In the present work we demonstrate that linker amino acids promote engagement with DNA. In the absence of linker contacts, H-NS binding is significantly reduced, although no change in chromosome compaction is observed. H-NS is not localized to two distinct foci; rather, it is scattered all around the nucleoid. The linker makes DNA contacts that are required for gene silencing, while chromosome compaction does not appear to be an important H-NS function. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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