Department of Chemistry, Molecular Sciences Research Hub, Imperial College London, 82 Wood Lane, London W12 0BZ, United Kingdom.
Department of Microbiology, Harvard Medical School, 4 Blackfan Circle, Boston, Massachusetts 02115, United States.
ACS Chem Biol. 2022 Jun 17;17(6):1598-1606. doi: 10.1021/acschembio.2c00276. Epub 2022 Jun 1.
In the search for novel antimicrobial therapeutics, toxin-antitoxin (TA) modules are promising yet underexplored targets for overcoming antibiotic failure. The bacterial toxin Doc has been associated with the persistence of in macrophages, enabling its survival upon antibiotic exposure. After developing a novel method to produce the recombinant toxin, we have used antitoxin-mimicking peptides to thoroughly investigate the mechanism by which its cognate antitoxin Phd neutralizes the activity of Doc. We reveal insights into the molecular detail of the Phd-Doc relationship and discriminate antitoxin residues that stabilize the TA complex from those essential for inhibiting the activity of the toxin. Coexpression of Doc and antitoxin peptides in was able to counteract the activity of the toxin, confirming our results with equivalent sequences. Our findings provide key principles for the development of chemical tools to study and therapeutically interrogate this important class of protein-protein interactions.
在寻找新型抗菌治疗方法的过程中，毒素-抗毒素 (TA) 模块是克服抗生素失效的有前途但未充分探索的目标。细菌毒素 Doc 与巨噬细胞中的 持续存在有关，使其在抗生素暴露时能够存活。在开发出一种生产重组毒素的新方法后，我们使用抗毒素模拟肽来深入研究其同源抗毒素 Phd 中和 Doc 活性的机制。我们揭示了 Phd-Doc 关系的分子细节，并区分了稳定 TA 复合物的抗毒素残基和抑制毒素活性所必需的抗毒素残基。Doc 和抗毒素肽在 中的共表达能够抵消毒素的活性，这证实了我们用等效序列的 结果。我们的研究结果为开发用于研究和治疗性探究这一重要类蛋白质-蛋白质相互作用的化学工具提供了关键原则。
