A Specialized Polythioamide-Binding Protein Confers Antibiotic Self-Resistance in Anaerobic Bacteria.
Gude, F., Molloy, E.M., Horch, T., Dell, M., Dunbar, K.L., Krabbe, J., Groll, M., Hertweck, C.(2022) Angew Chem Int Ed Engl 61: e202206168-e202206168
- PubMed: 35852818 
- DOI: https://doi.org/10.1002/anie.202206168
- Primary Citation of Related Structures:  
7ZHD, 7ZHE - PubMed Abstract: 
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.
Organizational Affiliation: 
Research Unit Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knöll Institute, Adolf-Reichwein-Straße 23, 07745, Jena, Germany.