Gram-negative bacteria express structurally diverse lipoproteins in their cell envelope. Here, we find that approximately half of lipoproteins destined to the Escherichia coli outer membrane display an intrinsically disordered linker at their N terminus. Intrinsically disordered regions are common in proteins, but establishing their importance in vivo has remained challenging. As we sought to unravel how lipoproteins mature, we discovered that unstructured linkers are required for optimal trafficking by the Lol lipoprotein sorting system, whereby linker deletion re-routes three unrelated lipoproteins to the inner membrane. Focusing on the stress sensor RcsF, we found that replacing the linker with an artificial peptide restored normal outer-membrane targeting only when the peptide was of similar length and disordered. Overall, this study reveals the role played by intrinsic disorder in lipoprotein sorting, providing mechanistic insight into the biogenesis of these proteins and suggesting that evolution can select for intrinsic disorder that supports protein function.

革兰氏阴性菌在其细胞包膜中表达结构多样的脂蛋白。在这里，我们发现大约一半的脂蛋白注定要进入大肠杆菌外膜在其 N 末端显示出本质上无序的接头。本质上无序的区域在蛋白质中很常见，但在体内确定它们的重要性仍然具有挑战性。当我们试图解开脂蛋白如何成熟时，我们发现 Lol 脂蛋白分选系统的最佳运输需要非结构化接头，由此接头缺失将三种不相关的脂蛋白重新路由到内膜。着眼于应力传感器 RcsF，我们发现只有当肽的长度相似且无序时，用人工肽替换接头才能恢复正常的外膜靶向。总的来说，这项研究揭示了内在紊乱在脂蛋白分选中所起的作用，