RNA二级结构的6-D表示及相似性分析

The 6-D representation of RNA secondary structures and the analysis of similarity

根据RNA二级结构组成,用A′,U′,G′,C′分别表示基对A-U,G-C和基对G-U中的A,U,G,C,将RNA二级结构转化为基本序列,称之为RNA二级结构的特征序列。在此基础上再根据核苷酸A,C,G,U的化学结构在6-D空间中定义了使核苷酸集与点集之间一一对应的函数,进而利用这个函数在6-D空间中得到了RNA二级结构的6-D表示,然后基于6-D表示把它转化为L/L矩阵表示和特征向量P=(μx,μy,μz,μk,μl,μm)表示,其中μi表示点集对应坐标分量的均值,最后利用矩阵不变量:即L/L矩阵的最大特征值,还有特征向量之间的距离来描述序列或结构的不变性来分析了AIMV-3等九种病毒的RNA二级结构的相似性,得到了比较好的结果。

According to the composition of RNA secondary structure, the RNA secondary structure is transformed into basic sequence by A＇, U＇, G＇, C＇ representing the A, U, G, C in the base - pairs of A - U, G - C and G - U, and we call it the characteristic sequence. On the basis of it, we define a function between the nucleotide sets and point sets in the 6 - D space by the chemical structures of the bases of A, C, G, U. Then we get the 6 - dimen- sional representation of RNA secondary structure in the 6 - D space. Furthermore, we transform the representation into L/L matrix and characteristic vector P = （μx,y,μz,μk,μi,μm ）, where μi means the average values of the corresponding sub - coordinate of the vector. In the end, the similarity of the RNA secondary structures of AIMV - 3 and the other 8 kinds of viruses are analyzed and some better results are obtained making use of the matrix invariant ： the leading eigenvalues of the L/L matrix and the distances between the characteristic vectors, which describe the invariance of the sequences or the structures.