pDetermination of the 59-terminal sequences flanking all the individual cleavage sites for endonuclease AvaI in bacteriophage-lambda DNA has shown that this enzyme recognizes the hexanucleotide sequences: (Formula: see text), This sequence is cut as shown by the arrows to give single-stranded 59-tetranucleotide protrusions (cohesive ends). Endonucleases SmaI, XhoI and XmaI recognize different symmetrical subsets of this sequence and provide independent evidence for the occurrence of these subsets at particular endonuclease-AvaI cleavage sites in the bacteriophage-lambda genome. Further evidence for this structure came from the demonstration that DNA fragments generated by endonuclease AvaI can be ligated to form a discrete set of larger molecules and from nearest-neighbor analysis which showed that cytosine residues occurred at the 39-side of cleavage points. The observation that endonuclease AvaII recognized a subset of the sites recognized by AsuI [Hughes, Bruce & Murray (1979) Biochem. J. 185, 59-63[led to the deduction that AvaII recognize the pentanucleotide sequence: (Formula: see text), and breaks internucleotide bonds at the positions indicated by the arrows./p
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机译:>确定噬菌体-λDNA中所有核酸内切酶AvaI的单个切割位点两侧的59端序列已表明该酶可识别六核苷酸序列:(分子式:见正文),该序列如箭头所示被切割得到单链的59-四核苷酸突出部分(粘性末端)。内切核酸酶SmaI,XhoI和XmaI识别该序列的不同对称子集,并为这些子集在噬菌体-λ基因组中特定内切核酸酶-AvaI切割位点的发生提供了独立的证据。这种结构的进一步证据来自证明核酸内切酶AvaI产生的DNA片段可以连接形成离散的较大分子组的证据,以及来自最近邻分析的结果,该分析表明胞嘧啶残基出现在切割点的39侧。核酸内切酶AvaII识别AsuI识别的位点的子集的观察[Hughes,Bruce& A. Murray(1979)生物化学。 J. 185,59-63 [推论推论AvaII识别五核苷酸序列:(公式:参见文本),并在箭头所示的位置断开核苷酸间键。 p>
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