【作者】 王晓雷； 陈启华； 吴更； 许平； 赵一雷；

【Author】 Xiao-Lei Wang;Qihua Chen;Geng Wu;Ping Xu;Yi-Lei Zhao;State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology,Shanghai Jiao Tong University;

【机构】 上海交通大学微生物代谢国家重点实验室；

【摘要】 <正>在烟草废弃物有机污染物微生物降解中,恶臭假单胞菌S16尼古丁吡咯降解途径关键酶N-甲酰马来酰胺酸去甲酰基酶(Nfo)和马来酰胺脱酰胺酶(Ami)分别负责进入主代谢三羧酸循环系统前的两步脱氮反应。我们对该微生物代谢途径的两个功能高度类似但具有完全不同底物选择性的酰胺水解酶的结构进行了理论计算研究[1-2],通过对Nfo和Ami的蛋白晶体结构与底物分子的对接和能量分析,识别在底物结合和催化中发挥重要作用的氨基酸残基,并通过酶学突变实验进行验证,证明了Nfo和Ami具有特异性降解各自底物N-甲更多还原

【Abstract】 Nfo and Ami are the two amide hydrolases in tobacco microbial degradation by Pseudomonas putida S16, responsible for sequential denitrogenations of the nicotine pyrrole pathway before Krebs cycle. Here we investigated the substrate selectivity of Nfo and Ami, based on the crystal structures of the two enzyme. Using molecular docking and conformation analysis, we observed that Ser94-His238-Asp118 in Nfo and Cys150-Asp29-Lys117 in Ami were respectively the triads, and accordingly the substrate selectivity was rationalized by the neighboring residues. Conclusively, the two amide hydrolases possess the different attacking groups and recognition mechanisms.更多还原