Harnett S P, Lowe G, Tansley G
Biochemistry. 1985 Dec 3;24(25):7446-9. doi: 10.1021/bi00346a062.
RNA ligase from bacteriophage T4 infected Escherichia coli catalyzes the activation of adenosine 3',5'-bisphosphate (representing the donor oligonucleotide) by adenosine 5'-[(S)-alpha-17O,alpha,alpha-18O2]triphosphate with retention of configuration at P alpha. Since single-step enzyme-catalyzed nucleotidyl transfer reactions proceed with inversion, this stereochemical result provides support for a double displacement mechanism involving an adenylyl-enzyme intermediate as proposed previously from isotope exchange experiments.
来自受噬菌体T4感染的大肠杆菌的RNA连接酶催化3',5'-二磷酸腺苷（代表供体寡核苷酸）被5'-[(S)-α-17O,α,α-18O2]三磷酸腺苷激活，且在Pα处构型保持不变。由于单步酶催化的核苷酸转移反应是构型翻转进行的，所以这种立体化学结果为先前从同位素交换实验中提出的涉及腺苷酰 - 酶中间体的双取代机制提供了支持。
