Two Cryptic Self-Resistance Mechanisms in Streptomyces tenebrarius Reveal Insights into the Biosynthesis of Apramycin
Two Cryptic Self-Resistance Mechanisms in Streptomyces tenebrarius Reveal Insights into the Biosynthesis of Apramycin
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近链霉菌中的两种隐秘的自我抵抗机制揭示了对安普霉素生物合成的见解
DOI：
10.1002/anie.202100687
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发表时间：
2021-03-05
影响因子：
16.6
通讯作者：
Yu, Yi
中科院分区：
文献类型：
--
作者：
Zhang, Qian;Chi, Hao-Tian;Yu, Yi
安普霉素是一种具有临床应用前景的氨基糖苷类抗生素（阿加）。到目前为止，安普霉素的生物合成和自身抗性的机制仍然很大程度上未知。在这里，我们报告说，安普霉素的生物合成过程中，通过意想不到的磷酸化，脱乙酰化和脱磷酸化的步骤，其中一个新的氨基糖苷磷酸转移酶（AprU），一个假定的肌酐酰胺水解酶（AprP），和碱性磷酸酶（AprZ）参与。生物化学表征显示AprU特异性磷酸化假三糖中间体的5-OH，其N-7 '乙酰基随后被AprP水解。AprZ位于细胞外，从假四糖中间体中除去磷酸基团，导致安普霉素成熟。有趣的是，7 '-N-乙酰化和5-O-磷酸化的安普霉素分别在Δ aprU和Δ aprZ中积累，表现出显著降低的抗菌活性，这意味着黑暗链霉菌利用C-5磷酸化和N-7 '乙酰化作为两种策略来避免自毒。值得注意的是，这项研究为新一代AGA的设计提供了深入了解，以规避耐药病原体的出现。
Apramycin is a clinically promising aminoglycoside antibiotic (AGA). To date, mechanisms underlying the biosynthesis and self-resistance of apramycin remain largely unknown. Here we report that apramycin biosynthesis proceeds through unexpected phosphorylation, deacetylation, and dephosphorylation steps, in which a novel aminoglycoside phosphotransferase (AprU), a putative creatinine amidohydrolase (AprP), and an alkaline phosphatase (AprZ) are involved. Biochemical characterization revealed that AprU specifically phosphorylates 5-OH of a pseudotrisaccharide intermediate, whose N-7 ' acetyl group is subsequently hydrolyzed by AprP. AprZ is located extracellularly where it removes the phosphate group from a pseudotetrasaccharide intermediate, leading to the maturation of apramycin. Intriguingly, 7 '-N-acetylated and 5-O-phosphorylated apramycin that were accumulated in Delta aprU and Delta aprZ respectively exhibited significantly reduced antibacterial activities, implying Streptomyces tenebrarius employs C-5 phosphorylation and N-7 ' acetylation as two strategies to avoid auto-toxicity. Significantly, this study provides insight into the design of new generation AGAs to circumvent the emergence of drug-resistant pathogens.