The object of the invention is a Mini-III RNase with amino acid sequence comprising an acceptor part, and a transplantable a4 helix, and a transplantable a5b-a6 loop, which form structures of a4 helix and a5b-a6 loop, respectively, in the Mini-III RNase structure, wherein the fragments which form structures of a4 helix and a5b-a6 loop, respectively, correspond structurally to respective structures of a4 helix and a5b-a6 loop formed by amino acid sequence fragments 46-52 and 85-98, respectively, of Mini-III RNase from Bacillus stubtilis shown in SEQ ID NO: 1, wherein the said Mini-III RNase exhibits sequence specificity in dsRNA cleavage being dependent only on a ribonucleotide sequence of the substrate, and independent from an occurrence of secondary structures in the substrate's structure, and independent from a presence of other assisting proteins, and wherein the Mini-III RNase is not the Mini-III protein from Bacillus stubtilis of SEQ ID NO: 1, nor SEQ ID NO: 1 with D94R mutation. The invention also relates to a method of obtaining a chimeric Mini-III RNase, a Mini-III RNase encoding construct, a cell with a Mini-III RNase encoding gene, use of Mini-III RNase for dsRNA cleavage, as well as a method of dsRNA cleavage depending only on a ribonucleotide sequence.
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机译：本发明的目的是具有氨基酸序列的Mini-III RNase，其包含受体部分和可移植的a4螺旋和可移植的a5b-a6环，它们分别在其中形成a4螺旋和a5b-a6环的结构。 Mini-III RNase结构，其中分别形成a4螺旋和a5b-a6环结构的片段在结构上对应于由氨基酸序列片段46-52和85-98形成的a4螺旋和a5b-a6环的相应结构，分别由SEQ ID NO：1所示的芽孢杆菌（Bacillus stubtilis）的Mini-III RNase组成，其中所述Mini-III RNase在dsRNA切割中表现出序列特异性，其仅取决于底物的核糖核苷酸序列，并且不依赖于底物结构中二级结构的存在，也不依赖于其他辅助蛋白的存在，并且其中Mini-III RNase不是来自SEQ ID NO：芽孢杆菌的Mini-III蛋白：1，也没有带有D的SEQ ID NO：1 94R突变。本发明还涉及获得嵌合的Mini-III RNase，Mini-III RNase编码构建体，具有Mini-III RNase编码基因的细胞的方法，使用Mini-III RNase进行dsRNA切割的方法以及方法。仅取决于核糖核苷酸序列的dsRNA切割的序列。
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