Bacteria use various strategies to become antibiotic resistant. The molecular details of these strategies are not fully understood. We can increase our understanding by investigating the same strategies found in antibiotic-producing bacteria. In this work, we characterize the self-resistance protein Ecm16 encoded by echinomycin-producing bacteria. Ecm16 is a structural homolog of the nucleotide excision repair protein UvrA. Expression of ecm16 in the heterologous system Escherichia coli was sufficient to render resistance against echinomycin. Ecm16 binds DNA (double-stranded and single-stranded) using a nucleotide-independent binding mode. Ecm16’s binding affinity for DNA increased by 1.7-fold when the DNA is intercalated with echinomycin. Ecm16 can render resistance against echinomycin toxicity independently of the nucleotide excision repair system. Similar to UvrA, Ecm16 has ATPase activity, and this activity is essential for Ecm16’s ability to render echinomycin resistance. Notably, UvrA and Ecm16 were unable to complement each other's function. Together, our findings identify new mechanistic details of how a refurbished DNA repair protein Ecm16 can specifically render resistance to the DNA intercalator echinomycin.

中文翻译：

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UvrA 样蛋白 Ecm16 需要 ATP 酶活性才能对棘霉素产生抗性

细菌使用各种策略来产生抗生素耐药性。这些策略的分子细节尚不完全清楚。我们可以通过研究在产生抗生素的细菌中发现的相同策略来增加我们的理解。在这项工作中，我们描述了由产生棘霉素的细菌编码的自抗性蛋白 Ecm16。Ecm16 是核​​苷酸切除修复蛋白 UvrA 的结构同源物。ecm16在异源系统大肠杆菌中的表达足以产生对棘霉素的抗性。Ecm16 使用不依赖核苷酸的结合模式结合 DNA（双链和单链）。当 DNA 插入棘霉素时，Ecm16 对 DNA 的结合亲和力增加了 1.7 倍。Ecm16 可以独立于核苷酸切除修复系统对棘霉素毒性产生抗性。与 UvrA 类似，Ecm16 具有 ATPase 活性，这种活性对于 Ecm16 产生棘霉素抗性的能力至关重要。值得注意的是，UvrA 和 Ecm16 无法互补彼此的功能。总之，我们的研究结果确定了翻新的 DNA 修复蛋白 Ecm16 如何特异性地呈现对 DNA 嵌入剂棘霉素的抗性的新机制细节。