Shishido K, Ando T
Biochim Biophys Acta. 1981 Nov 27;656(1):123-7. doi: 10.1016/0005-2787(81)90035-6.
Covalently closed-circular, superhelical SV4O DNA was used in all experiments. EcoRI endonuclease- and HpaII endonuclease-generated unit-length linear duplex DNAs were digested with S1 endonuclease under the conditions where single-stranded CNA was completely converted into the acid-soluble form. These were subjected to an end-to-end joining test with T4 DNA ligase. The ligation efficiency was significantly lower than that of the flush-ended linear duplex DNAs which were generated by both HpaI endonuclease digestion and the matching up of EcoRI-generated sticky end with Escherichia coli DNA polymerase I (Klenow fraction). However, the ligation efficiency of the S1-treated DNAs increased up to same level as the flush-ended DNA upon treatment with E. coli DNA polymerase I . Similar results were obtained in the case of S1 -generated unit-length linear duplex DNA. S1 does cleave both strands of superhelical DNA at unbasepaired sites.
所有实验均使用共价闭合环状、超螺旋的SV40 DNA。用EcoRI核酸内切酶和HpaII核酸内切酶产生的单位长度线性双链DNA在单链CNA完全转化为酸溶性形式的条件下用S1核酸内切酶消化。将这些产物用T4 DNA连接酶进行端对端连接测试。连接效率显著低于由HpaI核酸内切酶消化以及用大肠杆菌DNA聚合酶I（Klenow片段）使EcoRI产生的粘性末端配对所产生的平端线性双链DNA的连接效率。然而，在用大肠杆菌DNA聚合酶I处理后，经S1处理的DNA的连接效率提高到与平端DNA相同的水平。在S1产生的单位长度线性双链DNA的情况下也获得了类似的结果。S1确实会在未配对位点切割超螺旋DNA的两条链。
