Darobactin B Stabilises a Lateral-Closed Conformation of the BAM Complex in E. coli Cells
Darobactin B Stabilises a Lateral-Closed Conformation of the BAM Complex in E. coli Cells
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Darobactin B 稳定大肠杆菌细胞中 BAM 复合物的横向闭合构象
DOI：
10.1002/ange.202218783
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发表时间：
2023
影响因子：
--
通讯作者：
Haysom S
中科院分区：
文献类型：
--
作者：
Haysom S
β-桶组装机制（BAM复合物）对于革兰氏阴性菌中的外膜蛋白（OMP）折叠至关重要，并且代表了一种有前途的抗菌靶标。已经报道了BAM的几种构象状态，但是所有这些都是在缺乏外膜（OM）的独特特征和复杂性的条件下获得的。在这里，我们使用脉冲电子-电子双共振（PELDOR或DEER）光谱距离测量来询问大肠杆菌细胞中BAM复合物的构象系综。 我们发现BAM在OM中采用了广泛的构象系综，而在抗生素darobactin B（DAR B）的存在下，BAM的构象平衡转移到与侧向闭合状态一致的受限系综。我们的细胞内PELDOR发现得到了存在和不存在DAR B的BAM的新cryoEM结构的支持。这项工作证明了PELDOR在其天然细胞环境中映射BAM构象变化的实用性。
The β‐barrel assembly machinery (BAM complex) is essential for outer membrane protein (OMP) folding in Gram‐negative bacteria, and represents a promising antimicrobial target. Several conformational states of BAM have been reported, but all have been obtained under conditions which lack the unique features and complexity of the outer membrane (OM). Here, we use Pulsed Electron‐Electron Double Resonance (PELDOR, or DEER) spectroscopy distance measurements to interrogate the conformational ensemble of the BAM complex inE. colicells. We show that BAM adopts a broad ensemble of conformations in the OM, while in the presence of the antibiotic darobactin B (DAR‐B), BAM′s conformational equilibrium shifts to a restricted ensemble consistent with the lateral closed state. Our in‐cell PELDOR findings are supported by new cryoEM structures of BAM in the presence and absence of DAR‐B. This work demonstrates the utility of PELDOR to map conformational changes in BAM within its native cellular environment.