Histone‐like nucleoid‐structuring protein (H‐NS) and integration host factor (IHF) are major nucleoid‐associated proteins, and DnaA, a replication initiator, may also be related with nucleoid compaction. It has been shown that protein‐dependent DNA compaction is related with many aspects of bacterial physiology, including transcription, DNA replication, and site‐specific recombination. However, the mechanism of bacterial physiology resulting from nucleoid compaction remains unknown. Here, we show that H‐NS is important for correct nucleoid compaction in a medium‐independent manner. H‐NS‐mediated nucleoid compaction is not required for correct cell division, but the latter is dependent on H‐NS in rich medium. Further, it is found that the IHFα‐mediated nucleoid compaction is needed for correct cell division, and the effect is dependent on medium. Also, we show that the effects of H‐NS and IHF on nucleoid compaction are cumulative. Interestingly, DnaA also plays an important role in nucleoid compaction, and the effect of DnaA on nucleoid compaction appears to be related to cell division in a medium‐dependent manner. The results presented here suggest that scrambled initiation of replication, improper cell division, and slow growth is likely associated with disturbances in nucleoid organization directly or indirectly.

中文翻译：

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H-NS、IHF 和 DnaA 导致类核组织、复制起始和细胞分裂的变化

组蛋白样核苷结构蛋白 (H-NS) 和整合宿主因子 (IHF) 是主要的核苷相关蛋白，复制起始因子 DnaA 也可能与核苷压缩有关。已经表明，蛋白质依赖性 DNA 压缩与细菌生理学的许多方面有关，包括转录、DNA 复制和位点特异性重组。然而，由类核压实引起的细菌生理学机制仍然未知。在这里，我们表明 H-NS 对于以介质无关的方式正确的类核压实很重要。正确的细胞分裂不需要 H-NS 介导的类核压实，但后者依赖于富培养基中的 H-NS。此外，发现正确的细胞分裂需要 IHFα 介导的类核压实，其效果取决于培养基。此外，我们表明 H-NS 和 IHF 对类核压实的影响是累积的。有趣的是，DnaA 在类核压实中也起着重要作用，DnaA 对类核压实的影响似乎与细胞分裂以介质依赖的方式有关。此处呈现的结果表明，复制开始的混乱、细胞分裂不当和生长缓慢可能与类核组织的紊乱直接或间接相关。