N‐acetylglucosamine 6‐phosphate deacetylase (NagA) catalyzes the conversion of N‐acetylglucosamine‐6‐phosphate to glucosamine‐6‐phosphate in amino sugar catabolism. This conversion is an essential step in the catabolism of sialic acid in several pathogenic bacteria, including Pasteurella multocida, and thus NagA is identified as a potential drug target. Here, we report the unique structural features of NagA from P. multocida (PmNagA) resolved to 1.95 Å. PmNagA displays an altered quaternary architecture with unique interface interactions compared to its close homolog, the Escherichia coli NagA (EcNagA). We confirmed that the altered quaternary structure is not a crystallographic artifact using single particle electron cryo‐microscopy. Analysis of the determined crystal structure reveals a set of hot‐spot residues involved in novel interactions at the dimer‐dimer interface. PmNagA binds to one Zn²⁺ ion in the active site and demonstrates kinetic parameters comparable to other bacterial homologs. Kinetic studies reveal that at high substrate concentrations (~10‐fold the K_M), the tetrameric PmNagA displays hysteresis similar to its distant neighbor, the dimeric Staphylococcus aureus NagA (SaNagA). Our findings provide key information on structural and functional properties of NagA in P. multocida that could be utilized to design novel antibacterials.

中文翻译：

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来自多杀巴斯德氏菌的N-乙酰氨基葡萄糖-6-磷酸脱乙酰酶的结构组装中的第四纪变化。

N-乙酰氨基葡萄糖6-磷酸脱乙酰酶（NagA）在氨基糖分解代谢中催化N-乙酰氨基葡萄糖6-磷酸向氨基葡萄糖6-磷酸的转化。该转化是唾液酸在多种致病菌（包括多杀巴斯德氏菌）中分解的必不可少的步骤，因此，NagA被确定为潜在的药物靶标。在这里，我们报告了来自多杀性疟原虫（PmNagA）的NagA的独特结构特征，解析为1.95Å。与紧密同源的大肠杆菌相比，PmNagA显示出改变后的四级结构，具有独特的界面相互作用NagA（EcNagA）。我们证实，使用单粒子电子冷冻显微镜观察到，改变后的四级结构不是晶体伪像。对确定的晶体结构的分析揭示了一组热点残基，这些残基参与了二聚体-二聚体界面的新型相互作用。PmNagA在活性位点与一个Zn ²⁺离子结合，并显示出与其他细菌同源物相当的动力学参数。动力学研究显示，在高底物浓度（〜10倍的ķ_中号），四聚体PmNagA显示滞后类似于其遥远的邻居，二聚体金黄色葡萄球菌NAGA（SaNagA）。我们的发现提供了关于P. multocida中NagA的结构和功能特性的关键信息 可用于设计新型抗菌剂。