Fujii S, Tanaka Y, Uesugi S, Tanaka T, Sakata T, Hiroaki H
Faculty of Pharmaceutical Sciences, Osaka University, Japan.
Nucleic Acids Symp Ser. 1992(27):63-4.
A tridecaribonucleotide, r(UGAGCUUCGGCUC) doesn't form hairpin or interior loop and forms a double helix of 12 base pairs including the four successive nonstandard base pairs, U.G-U.C-C.U-G.U, in the crystal. Non-Watson-Crick base pairs, G.U and U.C are nicely incorporated in RNA duplex maintaining the regular A-form backbone. There exist the good overlapping between base pairings, U.G and U.C, so as to stabilize the nonstandard base pair track. Hydrogen bond networks involving water molecules in the major and minor grooves to stabilize this mismatch base pairing array, are observed and its conformational features are described.
一个十三聚体核糖核苷酸r(UGAGCUUCGGCUC)在晶体中不形成发夹或内环，而是形成一个包含四个连续非标准碱基对U.G-U.C-C.U-G.U的12个碱基对的双螺旋结构。非沃森-克里克碱基对G.U和U.C很好地融入RNA双链体中，维持着规则的A-型骨架。碱基对U.G和U.C之间存在良好的重叠，从而稳定了非标准碱基对序列。观察到在大沟和小沟中涉及水分子的氢键网络来稳定这种错配碱基对排列，并描述了其构象特征。
