Nodusmicin and 18-O-acetyl-nodusmicin were isolated as a co-metabolite of nargenicin from Nocardia sp. CS682. NgnL belonging to the α/β-hydrolase superfamily was heterologously expressed in Escherichia coli BL21 and was evaluated for its potential for acetylation of nodusmicin by in-vitro reactions. The generation of 18-O-acetyl nodusmicin was confirmed by high resolution-quadruple time of flight mass spectrometry (HR-QTOF-MS). Thus, it was concluded that NgnL can perform regiospecific acetylation of nodusmicin at 18-OH in presence of acetyl-CoA as an acetate donor. The enzyme kinetic parameters as Km and Vmax of the enzymes were also evaluated. Further, the biosynthetic role of the enzyme for acetylation of nodusmicin was confirmed by gene inactivation and complementation studies. Hence, from this study, it was established that NgnL is regiospecific acetyltransferase involved in the biosynthesis of 18-O-acetyl nodusmicin in Nocardia sp. CS682.

从诺卡氏菌（Nocardia sp。）分离出诺奇霉素和18 - O-乙酰基-诺奇霉素作为nargenicin的共代谢物。CS682。属于α/β-水解酶超家族的NgnL在大肠杆菌BL21中异源表达，并通过体外反应评估了其对Nososmicin乙酰化的潜力。18- O的产生高分辨率四倍飞行时间质谱法（HR-QTOF-MS）证实了-乙酰诺地霉素。因此，得出的结论是，在作为乙酸酯供体的乙酰辅酶A存在下，NgnL可以在18-OH上执行根瘤菌素的区域特异性乙酰化。还评估了酶的动力学参数，如Km和Vmax。此外，通过基因失活和互补研究证实了该酶对于根瘤菌素乙酰化的生物合成作用。因此，从该研究中，可以确定NgnL是参与诺卡氏菌属中18- O-乙酰基诺地霉素的生物合成的区域特异性乙酰基转移酶。CS682。