Armstrong K A, Bauer W R
Nucleic Acids Res. 1983 Jun 25;11(12):4109-26. doi: 10.1093/nar/11.12.4109.
Cleavage of pBR322 DNA I by the restriction endonuclease HinfI is preferentially inhibited at specific HinfI cleavage sites. These sites in pBR322 DNA I have been identified and ordered with respect to the frequency with which they are cleaved. The HinfI site most resistant to cleavage in pBR322 DNA I is unique in that runs of G-C base pairs are immediately adjacent on both sites. Two differently permuted linear (DNA III) species were produced by cleavage with two different restriction endonucleases, PstI and AvaI. Only one of these linear molecules, that produced by PstI, exhibits the same preferential cleavage pattern as DNA I. The second linear species, that arising from AvaI digestion, shows pronounced relative inhibition of cleavage at the HinfI sites nearest the ends of the molecule (100 to 120 base pairs away, respectively). This result suggest that proximity to the termini of a linear DNA molecule might also influence preferential cleavage. The possibility of formation of stem-loop structures does not appear to influence preferential cleavage by HinfI.
限制性内切酶HinfI对pBR322 DNA I的切割在特定的HinfI切割位点受到优先抑制。已确定pBR322 DNA I中的这些位点，并根据它们被切割的频率进行了排序。pBR322 DNA I中对切割最具抗性的HinfI位点是独特的，因为在两个位点上G-C碱基对的序列紧邻。用两种不同的限制性内切酶PstI和AvaI切割产生了两种不同排列的线性（DNA III）分子。这些线性分子中只有一种，即由PstI产生的分子，表现出与DNA I相同的优先切割模式。第二种线性分子，即由AvaI消化产生的分子，在最靠近分子末端（分别相距100至120个碱基对）的HinfI位点处显示出明显的相对切割抑制。这一结果表明，靠近线性DNA分子的末端也可能影响优先切割。茎环结构的形成可能性似乎不影响HinfI的优先切割。
