Sgaramella V, Van de Sande J H, Khorana H G
Proc Natl Acad Sci U S A. 1970 Nov;67(3):1468-75. doi: 10.1073/pnas.67.3.1468.
The polynucleotide ligase isolated from T4-infected Escherichia coli was previously shown to bring about repair of breaks in the single strands of bihelical DNA. The present work shows that the enzyme can also catalyze the joining of DNA duplexes at their base-paired ends. This novel reaction occurs when the deoxynucleoside at a 5'-end carries a phosphate group and the complementary deoxynucleoside opposite to it carries a 3'-hydroxyl group. The consequence is the lengthening of the original duplex to form dimers or oligomers depending upon whether one or both ends are base-paired.
先前已表明,从感染T4噬菌体的大肠杆菌中分离出的多核苷酸连接酶能够修复双螺旋DNA单链中的断裂处。目前的研究表明,该酶还能催化DNA双链在其碱基配对末端的连接。当5'-末端的脱氧核苷带有磷酸基团,且与之相对的互补脱氧核苷带有3'-羟基时,就会发生这种新反应。其结果是,根据一端还是两端进行碱基配对,原始双链会延长形成二聚体或寡聚体。