Marles-Wright Jon, Grant Tim, Delumeau Olivier, van Duinen Gijs, Firbank Susan J, Lewis Peter J, Murray James W, Newman Joseph A, Quin Maureen B, Race Paul R, Rohou Alexis, Tichelaar Willem, van Heel Marin, Lewis Richard J
Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle-upon-Tyne NE2 4HH, UK.
Science. 2008 Oct 3;322(5898):92-6. doi: 10.1126/science.1159572.
A commonly used strategy by microorganisms to survive multiple stresses involves a signal transduction cascade that increases the expression of stress-responsive genes. Stress signals can be integrated by a multiprotein signaling hub that responds to various signals to effect a single outcome. We obtained a medium-resolution cryo-electron microscopy reconstruction of the 1.8-megadalton "stressosome" from Bacillus subtilis. Fitting known crystal structures of components into this reconstruction gave a pseudoatomic structure, which had a virus capsid-like core with sensory extensions. We suggest that the different sensory extensions respond to different signals, whereas the conserved domains in the core integrate the varied signals. The architecture of the stressosome provides the potential for cooperativity, suggesting that the response could be tuned dependent on the magnitude of chemophysical insult.
微生物用于在多种压力下存活的一种常用策略涉及一个信号转导级联反应，该反应会增加应激反应基因的表达。应激信号可由一个多蛋白信号枢纽整合，该枢纽对各种信号作出反应以实现单一结果。我们获得了来自枯草芽孢杆菌的180万道尔顿“应激体”的中等分辨率冷冻电子显微镜重建图像。将已知的组分晶体结构拟合到该重建图像中得到了一个准原子结构，其具有类似病毒衣壳的核心和传感延伸部分。我们认为，不同的传感延伸部分对不同的信号作出反应，而核心中的保守结构域整合各种信号。应激体的结构提供了协同作用的可能性，这表明反应可以根据化学物理损伤的程度进行调节。
