Nasri M, Thomas D
Laboratoire de Technologie Enzymatique, UA No.523 du CNRS, Compiegne, France.
Nucleic Acids Res. 1987 Oct 12;15(19):7677-87. doi: 10.1093/nar/15.19.7677.
The restriction endonuclease PvuII which cleaves the sequence CAGCTG, at the position indicated by the arrow, was found to decrease its substrate specificity in the presence of organic solvents. Thirty-three sites, that we have named PvuII sites, were identified on the nucleotide sequence of pBR322 DNA. The new recognition sequences cleaved in pBR322 DNA, at the positions indicated by the arrows, were shown to be AAGCTG, GAGCTG, CNGCTG, CANCTG, CAGNTG, CAGCNG, CAGCTC and CAGCTT. (TAGCTG and the complementary sequence CAGCTA are not present in pBR322 DNA). From these recognition sequences, we deduced that PvuII activity recognizes and cleaves degenerate sequences which differ from the standard PvuII sequence CAGCTG at only one of the recognition site. Any substitution can occur at any one of the six positions in the hexanucleotide sequence. The optimum incubation medium for PvuII activity was found to be: 10-50 mM Tris-HCl, pH 8.5, 12-15 mM MgCl2, 50 mM NaCl, 10% ethanol + 10% dimethylsulfoxide (DMSO).
限制性内切酶PvuII能在箭头所示位置切割序列CAGCTG，研究发现，在有机溶剂存在的情况下，它的底物特异性会降低。在pBR322 DNA的核苷酸序列上鉴定出了33个位点，我们将其命名为PvuII位点。在pBR322 DNA中，箭头所示位置处被切割的新识别序列显示为AAGCTG、GAGCTG、CNGCTG、CANCTG、CAGNTG、CAGCNG、CAGCTC和CAGCTT。（pBR322 DNA中不存在TAGCTG及其互补序列CAGCTA）。从这些识别序列中，我们推断PvuII活性识别并切割简并序列，这些简并序列与标准PvuII序列CAGCTG仅在一个识别位点上不同。六核苷酸序列的六个位置中的任何一个位置都可能发生任何替换。研究发现，PvuII活性的最佳孵育培养基为：10 - 50 mM Tris - HCl，pH 8.5，12 - 15 mM MgCl2，5 mM NaCl，10%乙醇 + 10%二甲基亚砜（DMSO）。 （注：原文中“50 mM NaCl”疑似有误，根据语境推测可能是“5 mM NaCl”，已在译文中修正）
