产品内容
本酶催化的反应为ATP + [RNA]-3'-(3'-Phospho-Ribonucleoside) = AMP + Diphosphate + [RNA]-3'-(2',3'-Cyclophospho)-Ribonucleoside (Overall Reaction);;(1a) ATP + [RNA 3'-Phosphate Cyclase]-L-Histidine = [RNA 3'-Phosphate Cyclase]-Ntau-(5'-Adenylyl)-L-Histidine + Diphosphate;;(1b) [RNA 3'-Phosphate Cyclase]-Ntau-(5'-Adenylyl)-L-Histidine + [RNA]-3'-(3'-Phospho-Ribonucleoside) = [RNA 3'-Phosphate Cyclase]-L-Histidine + [RNA]-3'-Ribonucleoside-3'-(5'-Diphosphoadenosine);;(1c) [RNA]-3'-Ribonucleoside-3'-(5'-Diphosphoadenosine) = [RNA]-3'-(2',3'-Cyclophospho)-Ribonucleoside + AMP，系统名称为RNA-3'-Phosphate:RNA Ligase (Cyclizing, AMP-Forming)，该酶在ATP依赖的反应中将各种RNA底物的3'-末端磷酸转化为2',3'-环状磷酸二酯。催化通过三步机制进行：首先酶被ATP激活，在腺苷酸和组氨酸残基之间形成磷酰胺键[5,6]。然后腺苷酸基团被转移至底物的3'-磷酸末端，形成加帽结构[RNA]-3'-（5'-二磷酸腺苷）。最后，该酶催化邻位O-2'对3'-磷的攻击，形成环状磷酸并释放腺苷酸。该酶也具有多核苷酸5'腺苷酰化活性[7]。参见EC 6.5.1.5，RNA 3'-末端磷酸环化酶（GTP）。
暂无数据！
扫码关注公众号
