Manganese-Induced Substrate Promiscuity in the Reaction Catalyzed by Phosphoglutamine Cytidylyltransferase from Campylobacter jejuni.
Manganese-Induced Substrate Promiscuity in the Reaction Catalyzed by Phosphoglutamine Cytidylyltransferase from Campylobacter jejuni.
复制标题
DOI：
10.1021/acs.biochem.9b00189
复制
发表时间：
2019-03
期刊：
影响因子：
2.9
通讯作者：
Zane W Taylor;F. Raushel
中科院分区：
文献类型：
--
作者：
Zane W Taylor;F. Raushel
细菌性胃肠炎的主要原因是空肠弯曲杆菌，其是革兰氏阴性病原体，其在其荚膜多糖上含有独特的O-甲基氨基磷酸酯（MeOPN）。以前，MeOPN与逃避宿主免疫应答和血清抗性有关。尽管MeOPN参与致病性，但这种修饰的完整生物合成是未知的;然而，已经阐明了前四个酶促步骤。该途径中的第二种酶Cj1416是CTP/磷酸谷氨酰胺胞苷酰转移酶，其催化焦磷酸从MgCTP被1-谷氨酰胺磷酸置换以形成CDP-1-谷氨酰胺。最初，预测Cj1416使用氨基磷酸酯形成胞苷二氨基磷酸酯，但用MgATP作为底物没有检测到活性。然而，在MnCTP存在下，Cj1416可以直接催化由氨基磷酸酯和MnCTP形成胞苷二氨基磷酸酯。在这里，我们的特点锰诱导的混杂的CJ1416。在Mn 2+存在下，Cj1416催化使用l-谷氨酰胺磷酸、氨基磷酸酯、磷酸甲酯、膦酸甲酯、磷酸盐、砷酸盐、乙醇胺磷酸盐、甘油-1-磷酸盐、甘油-2-磷酸盐、丝氨醇磷酸盐、l-丝氨酸磷酸盐或3-磷酸-d-甘油酸盐作为亲核试剂从CTP置换焦磷酸盐的12种不同反应产物的形成。
The leading cause of bacterial gastroenteritis, Campylobacter jejuni, is a Gram-negative pathogen that contains a unique O-methyl phosphoramidate (MeOPN) on its capsular polysaccharide. Previously, MeOPN has been linked to the evasion of host immune responses and serum resistance. Despite the involvement of MeOPN in pathogenicity, the complete biosynthesis of this modification is unknown; however, the first four enzymatic steps have been elucidated. The second enzyme in this pathway, Cj1416, is a CTP/phosphoglutamine cytididylyltransferase that catalyzes the displacement of pyrophosphate from MgCTP by l-glutamine phosphate to form CDP-l-glutamine. Initially, Cj1416 was predicted to use phosphoramidate to form cytidine diphosphoramidate, but no activity was detected with MgATP as a substrate. However, in the presence of MnCTP, Cj1416 can directly catalyze the formation of cytidine diphosphoramidate from phosphoramidate and MnCTP. Here we characterize the manganese-induced promiscuity of Cj1416. In the presence of Mn2+, Cj1416 catalyzes the formation of 12 different reaction products using l-glutamine phosphate, phosphoramidate, methyl phosphate, methyl phosphonate, phosphate, arsenate, ethanolamine phosphate, glycerol-1-phosphate, glycerol-2-phosphate, serinol phosphate, l-serine phosphate, or 3-phospho-d-glycerate as the nucleophile to displace pyrophosphate from CTP.