Ghosh R K, Deutscher M P
J Biol Chem. 1978 Feb 25;253(4):997-1000.
A nuclease (RNase D) that can recognize structurally altered transfer RNA molecules has been partially purified from Escherichia coli. The enzyme acts poorly on intact tRNA and is inactive with the synthetic polyribonucleotides, poly(A), poly(U), or double-stranded poly(A).poly(U). The enzyme requires Mg2+ for activity and is stimulated by the monovalent cations, K+ and NH4+. The products of the reaction are 5'-mononucleotides. The molecular weight of the protein is about 60,000 as judged by Sephadex G-100 chromatography. The enzyme does not correspond to any known E. coli ribonuclease and may represent an intracellular scavenging mechanism for denatured tRNAs and other inactive RNA molecules.
一种能够识别结构改变的转运RNA分子的核酸酶（核糖核酸酶D）已从大肠杆菌中部分纯化出来。该酶对完整的tRNA作用不佳，对合成多聚核糖核苷酸、聚腺苷酸、聚尿苷酸或双链聚腺苷酸·聚尿苷酸没有活性。该酶的活性需要Mg2+，并受到单价阳离子K+和NH4+的刺激。反应产物是5'-单核苷酸。通过葡聚糖G-100层析法判断，该蛋白质的分子量约为60,000。该酶与任何已知的大肠杆菌核糖核酸酶都不对应，可能代表了一种针对变性tRNA和其他无活性RNA分子的细胞内清除机制。
