Increased bending rigidity of single DNA molecules by H-NS, a temperature and osmolarity sensor
Increased bending rigidity of single DNA molecules by H-NS, a temperature and osmolarity sensor
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DOI：
10.1016/s0006-3495(03)75051-6
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发表时间：
2003-04-01
影响因子：
3.4
通讯作者：
Stavans, J
中科院分区：
文献类型：
--
作者：
Amit, R;Oppenheim, AB;Stavans, J
组蛋白样类核结构蛋白（H-NS）是一种丰富的原核蛋白，参与类核结构、基因调控和沉默。它在细胞对温度和渗透压变化的反应中起着关键作用。单，扭转松弛的λ -DNA- h - ns复合物的力扩展测量表明，与裸DNA底物相比，这些复合物采用更扩展的构型。交联表明，H-NS可以每15- 20bp修饰一个H-NS二聚体。这些结果表明，H-NS沿着DNA聚合，形成更高弯曲刚度的复合物。这些效应在32℃以上或高渗透压下没有观察到，这支持了H-NS-DNA直接相互作用在基因沉默中起关键作用的假设。因此，我们认为H-NS具有不同于HU和IHF的独特结构作用，是细胞的环境传感器之一。
Histonelike nucleoid structuring protein (H-NS) is an abundant prokaryotic protein participating in nucleoid structure, gene regulation, and silencing. It plays a key role in cell response to changes in temperature and osmolarity. Force-extension measurements of single, twist-relaxed lambda-DNA-H-NS complexes show that these adopt more extended configurations compared to the naked DNA substrates. Crosslinking indicates that H-NS can decorate DNA molecules at one H-NS dimer per 15-20 bp. These results suggest that H-NS polymerizes along DNA, forming a complex of higher bending rigidity. These effects are not observed above 32degreesC or at high osmolarity, supporting the hypothesis that a direct H-NS-DNA interaction plays a key role in gene silencing. Thus, we propose that H-NS plays a unique structural role, different from that of HU and IHF, and functions as one of the environmental sensors of the cell.