Weiss B
J Biol Chem. 1976 Apr 10;251(7):1896-901.
Exonuclease III, a phosphatase-exonuclease specific for bihelical DNA, wn the preparation was endonuclease II, an activity specific for DNA that has been partially depurinated by treatment with methyl methanesulfonate. The two activities, which could not be separated by electrophoresis, by sedimentation, or by gel filtration, were associated with a single monomeric protein of 28,000 daltons. To explain how a relatively small protein could have such diverse activities, it is proposed that one site on the enzyme can recognize interstrand spaces created either by depurination or by spontaneous terminal unwinding of a DNA duplex.
核酸外切酶III是一种对双螺旋DNA具有特异性的磷酸酶-核酸外切酶，而制备物中的核酸内切酶II是一种对经甲磺酸甲酯处理而部分脱嘌呤的DNA具有特异性的活性。这两种活性不能通过电泳、沉降或凝胶过滤分离，它们与一种28,000道尔顿的单体蛋白相关联。为了解释一种相对较小的蛋白质如何能具有如此多样的活性，有人提出该酶上的一个位点可以识别由脱嘌呤或DNA双链自发末端解旋产生的链间空隙。
