Gram-negative bacteria depend on energised protein complexes that connect the two membranes of the cell envelope. However, β-barrel outer-membrane proteins (OMPs) and α-helical inner-membrane proteins (IMPs) display quite different organisation. OMPs cluster into islands that restrict their lateral mobility, while IMPs generally diffuse throughout the cell. Here, using live cell imaging of Escherichia coli, we demonstrate that when transient, energy-dependent transmembrane connections are formed, IMPs become subjugated by the inherent organisation of OMPs and that such connections impact IMP function. We show that while establishing a translocon for import, the colicin ColE9 sequesters the IMPs of the proton motive force (PMF)-linked Tol-Pal complex into islands mirroring those of colicin-bound OMPs. Through this imposed organisation, the bacteriocin subverts the outer-membrane stabilising role of Tol-Pal, blocking its recruitment to cell division sites and slowing membrane constriction. The ordering of IMPs by OMPs via an energised inter-membrane bridge represents an emerging functional paradigm in cell envelope biology.

中文翻译：

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膜间串扰驱动大肠杆菌中的内膜蛋白组织。

革兰氏阴性细菌依赖于活化的蛋白质复合物，该蛋白质复合物连接细胞膜的两个膜。然而，β-桶外膜蛋白（OMPs）和α-螺旋内膜蛋白（IMPs）表现出截然不同的组织。OMP聚集成岛，限制了它们的横向移动性，而IMP通常在整个细胞中扩散。在这里，使用大肠杆菌的活细胞成像，我们证明了当形成瞬态的，依赖能量的跨膜连接时，IMP被OMP的固有组织所束缚，并且这种连接会影响IMP的功能。我们显示，在建立进口转运体时，大肠菌素ColE9螯合质子动力（PMF）关联的Tol-Pal复合物的IMP进入岛，反映出与大肠素结合的OMPs。通过这个强加的组织，细菌素破坏了Tol-Pal的外膜稳定作用，阻止了Tol-Pal募集到细胞分裂部位并减慢了膜的收缩。OMP通过通电的跨膜桥对IMP的排序代表了细胞包膜生物学中一种新兴的功能范例。