Research Unit Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knöll Institute, Adolf-Reichwein-Straße 23, 07745, Jena, Germany.
Center for Protein Assemblies, Technical University of Munich, Ernst-Otto-Fischer-Straße 8, 85747, Garching, Germany.
Angew Chem Int Ed Engl. 2022 Sep 12;61(37):e202206168. doi: 10.1002/anie.202206168. Epub 2022 Aug 3.
Understanding antibiotic resistance mechanisms is central to the development of anti-infective therapies and genomics-based drug discovery. Yet, many knowledge gaps remain regarding the resistance strategies employed against novel types of antibiotics from less-explored producers such as anaerobic bacteria, among them the Clostridia. Through the use of genome editing and functional assays, we found that CtaZ confers self-resistance against the copper chelator and gyrase inhibitor closthioamide (CTA) in Ruminiclostridium cellulolyticum. Bioinformatics, biochemical analyses, and X-ray crystallography revealed CtaZ as a founding member of a new group of GyrI-like proteins. CtaZ is unique in binding a polythioamide scaffold in a ligand-optimized hydrophobic pocket, thereby confining CTA. By genome mining using CtaZ as a handle, we discovered previously overlooked homologs encoded by diverse members of the phylum Firmicutes, including many pathogens. In addition to characterizing both a new role for a GyrI-like domain in self-resistance and unprecedented thioamide binding, this work aids in uncovering related drug-resistance mechanisms.
了解抗生素耐药机制对于开发抗感染疗法和基于基因组学的药物发现至关重要。然而，对于来自较少探索的生产者（如厌氧菌，其中包括梭菌）的新型抗生素所采用的耐药策略，仍存在许多知识空白。通过使用基因组编辑和功能测定，我们发现 CtaZ 使 Ruminiclostridium cellulolyticum 能够对铜螯合剂和拓扑异构酶抑制剂 closthioamide (CTA) 产生自身耐药性。生物信息学、生化分析和 X 射线晶体学揭示 CtaZ 是一类新的 GyrI 样蛋白的创始成员。CtaZ 的独特之处在于结合配体优化的疏水性口袋中的聚硫酰胺支架，从而限制 CTA。通过使用 CtaZ 作为柄进行基因组挖掘，我们发现了以前被忽视的厚壁菌门不同成员编码的同源物，包括许多病原体。除了表征 GyrI 样结构域在自身耐药性中的新作用和前所未有的硫酰胺结合外，这项工作还有助于揭示相关的耐药机制。
