Ouyang Zhenlin, He Wenbo, Wu Di, An Hao, Duan Lei, Jiao Min, He Xiaoyu, Yu Qinyue, Zhang Jiaxin, Qin Qian, Wang Ruochen, Zheng Fang, Hwang Peter M, Hua Xiaoting, Zhu Li, Wen Yurong
Center for Microbiome Research of Med-X Institute, Department of Critical Care Medicine, Shaanxi Provincial Key Laboratory of Sepsis in Critical Care Medicine, The First Affiliated Hospital, Xi'an Jiaotong University, Xi'an 710061, China.
Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China.
Structure. 2025 Mar 6;33(3):539-551.e4. doi: 10.1016/j.str.2024.12.009. Epub 2025 Jan 10.
Multidrug-resistant Acinetobacter baumannii has emerged as one of the most antibiotic-resistant bacterial pathogens associated with nosocomial infection, with its resistance highly depending on multiple multidrug efflux pumps. Here, we report the cryoelectron microscopy (cryo-EM) structure of Acinetobacter drug efflux G (AdeG), the inner membrane component of one of three important resistance-nodulation-cell division (RND) pump family members in A. baumannii, which is involved in drug resistance to chloramphenicol, trimethoprim, ciprofloxacin, and clindamycin. We systematically compare the structures and substrate binding specificities of AdeG, AdeB, and AdeJ multidrug efflux pumps via molecular docking, revealing potential determinants for drug binding. Knockout experiments demonstrate a functional complementarity between AdeABC, AdeFGH, and AdeIJK. Our study provides a structural understanding of A. baumannii multidrug efflux pump AdeG and reveals complementary drug efflux activity between AdeG and other RND efflux pumps, which may promote further rational drug discovery efforts targeting multidrug efflux pumps.
多重耐药鲍曼不动杆菌已成为与医院感染相关的最具抗生素耐药性的细菌病原体之一，其耐药性高度依赖于多种多药外排泵。在此，我们报告了鲍曼不动杆菌药物外排G（AdeG）的冷冻电子显微镜（cryo-EM）结构，AdeG是鲍曼不动杆菌中三个重要的耐药-结瘤-细胞分裂（RND）泵家族成员之一的内膜成分，它参与对氯霉素、甲氧苄啶、环丙沙星和克林霉素的耐药。我们通过分子对接系统地比较了AdeG、AdeB和AdeJ多药外排泵的结构和底物结合特异性，揭示了药物结合的潜在决定因素。基因敲除实验证明了AdeABC、AdeFGH和AdeIJK之间的功能互补性。我们的研究提供了对鲍曼不动杆菌多药外排泵AdeG的结构理解，并揭示了AdeG与其他RND外排泵之间的互补药物外排活性，这可能会促进针对多药外排泵的进一步合理药物发现工作。
