Appierto V, Bardella L, Vijayasarathy C, Avadhani N, Sgaramella V, Biunno I
Istituto Tecnologie Biomediche Avanzate (ITBA), CNR, Milano, Italy.
Gene. 1997 Mar 25;188(1):119-22. doi: 10.1016/s0378-1119(96)00794-9.
Xib, a gene recently reported to reside on the q28 region of the human X chromosome [Pergolizzi et al. (1996) Gene 168, 267-270], contains an open reading frame homologous to those of the DNase I family enzymes. The full open reading frame of this gene has been fused to the E. coli gene of the maltose binding protein and expressed in bacteria as a chimeric protein. The partially purified chimeric protein is enzymatically active. It introduces single and double stranded breaks into supercoiled DNA, at 30 degrees C in the absence of divalent cations and at a pH optimum of 5.2. To our knowledge this enzyme represents the first cloned human endonuclease with characteristics similar to those of acidic DNase II.
Xib是一个最近报道位于人类X染色体q28区域的基因[佩尔戈利齐等人（1996年），《基因》168卷，267 - 270页]，它含有一个与脱氧核糖核酸酶I家族酶的开放阅读框同源的开放阅读框。该基因的完整开放阅读框已与麦芽糖结合蛋白的大肠杆菌基因融合，并作为嵌合蛋白在细菌中表达。部分纯化的嵌合蛋白具有酶活性。它在30摄氏度、不存在二价阳离子且最适pH为5.2的条件下，能在超螺旋DNA中产生单链和双链断裂。据我们所知，这种酶是第一个克隆的具有与酸性脱氧核糖核酸酶II相似特征的人类内切核酸酶。
