Pukkila P J
Mol Gen Genet. 1978 May 31;161(3):245-50. doi: 10.1007/BF00330997.
The activity of Ustilago maydis DNase I, an enzyme implicated in genetic recombination, on DNA substrates containing unpaired or mismatched bases, was examined. The enzyme nicked supercoiled PM-2 molecules, converting these to relaxed circular and linear molecules. Discrete double stranded linear fragments smaller than unit length were also observed after digestion at high enzyme concentration. Heteroduplex molecules were constructed using phi80 bacteriophage derivatives which contained single base substitutions within the E. coli tRNA1tyr gene. Single and double stranded nicking at or near the single mismatched site was observed with three out of the five pairs of heteroduplexes.
对玉米黑粉菌DNA酶I（一种与基因重组有关的酶）在含有未配对或错配碱基的DNA底物上的活性进行了检测。该酶切割超螺旋PM - 2分子，将其转化为松弛的环状和线性分子。在高酶浓度消化后，还观察到了小于单位长度的离散双链线性片段。使用在大肠杆菌tRNA1tyr基因内含有单碱基取代的φ80噬菌体衍生物构建异源双链分子。在五对异源双链分子中的三对中，在单个错配位点或其附近观察到了单链和双链切口。
