Bruce A G, Uhlenbeck O C
Nucleic Acids Res. 1978 Oct;5(10):3665-77. doi: 10.1093/nar/5.10.3665.
T4 RNA ligase will catalyze the addition of nucleoside 3', 5'-bisphosphates onto the 3' terminus of tRNA resulting in tRNA molecule one nucleotide longer with a 3' terminal phosphate. Under appropriate conditions the reaction is quantitative and, if high specific radioactivity bisphosphates are used, it provides an efficient means for in vitro labeling of tRNA. Although the 3' terminal hydroxyl is a good acceptor, the 5' terminal phosphate in most tRNA's is not an effective donor in the RNA ligase reaction. This poor reactivity is due to the secondary structure of the 5' terminal nucleotide. If E. Coli tRNAf Met is used, the 5' phosphate is reactive and the major product with RNA ligase is the cyclic tRNA.
T4 RNA连接酶会催化将核苷3',5'-双磷酸添加到tRNA的3'末端，使末端，使tRNA分子延长一个核苷酸，且3'末端带有磷酸基团。在适当条件下，该反应是定量的，如果使用高比放射性的双磷酸，则它为tRNA的体外标记提供了一种有效的方法。虽然3'末端羟基是良好的受体，但大多数tRNA中的5'末端磷酸在RNA连接酶反应中不是有效的供体。这种低反应活性是由于5'末端核苷酸的二级结构所致。如果使用大肠杆菌的tRNAf Met，5'磷酸具有反应活性，RNA连接酶的主要产物是环状tRNA。
