The H-NS (heat-stable nucleoid structuring) protein affects both nucleoid compaction and global gene regulation. H-NS appears to act primarily as a silencer of AT-rich genetic material acquired by horizontal gene transfer. As such, it is key in the regulation of most genes involved in virulence and in adaptation to new environmental niches. Here we review recent progress in understanding the biochemistry of H-NS and how xenogeneic silencing affects bacterial evolution. We highlight the strengths and weaknesses of some of the models proposed in H-NS-mediated nucleoprotein complex formation. Based on recent single-molecule studies, we also propose a novel mode of DNA compaction by H-NS termed intrabridging to explain over two decades of observations of the H-NS molecule.

中文翻译：

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异种沉默及其对细菌基因组的影响

H-NS（热稳定的类核苷酸结构）蛋白会影响类核苷酸的紧实和整体基因调控。H-NS似乎主要是通过水平基因转移获得的富含AT的遗传物质的沉默剂。因此，它是调控大多数与毒性相关的基因以及适应新环境的关键。在这里，我们回顾了了解H-NS的生物化学以及异种沉默如何影响细菌进化的最新进展。我们强调了在H-NS介导的核蛋白复合物形成中提出的某些模型的优缺点。基于最近的单分子研究，我们还提出了一种新的H-NS致密性DNA压缩模式，称为桥内杂交，以解释H-NS分子超过二十年的观察结果。