The structure of RseB: a sensor in periplasmic stress response of E. coli.
The structure of RseB: a sensor in periplasmic stress response of E. coli.
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DOI：
10.1016/j.jmb.2007.06.039
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发表时间：
2007-09
影响因子：
5.6
通讯作者：
P. Wollmann;K. Zeth
中科院分区：
文献类型：
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作者：
P. Wollmann;K. Zeth
在细菌细胞被膜中进化出一个优雅的信号转导网络，以响应环境压力。它是通过感知周质中不利和有害的变化而启动的。然后，通过跨膜抗σ因子RseA的受控降解传递应力信号，这导致替代σ因子σE的激活。周质蛋白RseB在调节RseA的稳定性中发挥关键作用。对大肠杆菌中的RseB进行了结晶，并在2.4 μ m和2.8 μ m分辨率下测定了晶体结构。蛋白质形成同二聚体，单体由两个结构域组成。大结构域类似于未闭合的β桶，其在结构上与能够结合脂蛋白的脂质锚的蛋白质家族非常相似。小的C-末端结构域通过部分非结构化的环连接到大的结构域，负责与RseA相互作用。基于RseB的结构，我们认为它是一个具有双重功能的周质应激传感器：它检测错误定位的脂蛋白，并传播信号以诱导σ E反应。
An elegant network of signal transduction has evolved in the bacterial cell envelope to respond to environmental stress. It is initiated by sensing unfavourable and harmful changes in the periplasm. The stress signal is then transmitted by a controlled degradation of the transmembrane anti-σ-factor RseA that leads to the activation of the alternative sigma factor σE. The periplasmic protein RseB exerts a crucial role in modulating the stability of RseA. RseB from Escherichia coli has been crystallized and crystal structures were determined at 2.4 Å and at 2.8 Å resolution. The protein forms a homodimer, with the monomer composed of two domains. The large domain resembles an unclosed β-barrel that is structurally remarkably similar to a protein family capable of binding the lipid anchor of lipoproteins. The small C-terminal domain, connected to the large domain by a partially unstructured loop, is responsible for interaction with RseA. On the basis of the structure of RseB, we suggest that it acts as a sensor of periplasmic stress with a dual functionality: it detects mislocalized lipoproteins and propagates the signal to induce the σE-response.