Diener J L, Moore P B
Department of Chemistry, Yale University, New Haven, Connecticut 06520-8107, USA.
Mol Cell. 1998 May;1(6):883-94.
The structure of the bulge-helix-bulge motif that constitutes the intron/exon splice site in H. volcanii pre-tRNATrp has been determined by NMR spectroscopy. The conformations of the two 3 nt bulges, where the pre-tRNA is cleaved, are stabilized by stacking interactions between bulge nucleotides and bases in the adjacent Watson-Crick helices and by a network of backbone hydrogen bonds. Both bulges are presented on the same minor groove face of the central 4 bp helix, and the overall structure has approximate two-fold symmetry, which makes it well-suited for attack by archaeal splicing endonucleases, which are symmetric dimers.
通过核磁共振光谱法已确定了构成火山栖热变形菌前体tRNATrp中内含子/外显子剪接位点的凸起-螺旋-凸起基序的结构。前体tRNA被切割的两个3核苷酸凸起的构象，通过凸起核苷酸与相邻沃森-克里克螺旋中的碱基之间的堆积相互作用以及主链氢键网络得以稳定。两个凸起都位于中央4碱基对螺旋的同一小沟面上，且整体结构具有近似的二重对称性，这使其非常适合被作为对称二聚体的古菌剪接内切核酸酶识别。
