Hegg L A, Kou M, Thurlow D L
Department of Chemistry, Clark University, Worcester, Massachusetts 01610.
J Biol Chem. 1990 Oct 15;265(29):17441-5.
The 3'-terminal tRNA-like structure of the tobacco mosaic virus RNA interacts with ATP/CTP:tRNA nucleotidyltransferases from Escherichia coli or yeast in much the same manner as do tRNAs. Primary sites of interaction cluster near the 3' end and in the loop proposed to be analogous to the psi-loop of a tRNA. Some modified bases in the tRNA-like structure inhibit interaction with nucleotidyltransferase, yet the analogous bases in a tRNA do not. The location of some of these nucleotides within the analog to the psi-loop suggests that this structure differs slightly from its counterpart in a tRNA. The location of other such bases in the helical stem near the 3' end can be explained if the pseudoknot is disrupted by these modified bases or if the tertiary structure of the RNA is altered in the enzyme-RNA complex. A partially denatured secondary structure that persists on denaturing gels is proposed.
烟草花叶病毒RNA的3'末端类似tRNA的结构与来自大肠杆菌或酵母的ATP/CTP:tRNA核苷酸转移酶相互作用，其方式与tRNA非常相似。相互作用的主要位点聚集在3'末端附近以及被认为类似于tRNA的ψ环的环中。类似tRNA结构中的一些修饰碱基会抑制与核苷酸转移酶的相互作用，而tRNA中的类似碱基则不会。这些核苷酸在类似ψ环中的一些位置表明，该结构与tRNA中的对应结构略有不同。如果假结被这些修饰碱基破坏，或者RNA的三级结构在酶-RNA复合物中发生改变，那么在3'末端附近螺旋茎中其他此类碱基的位置就可以得到解释。有人提出了一种在变性凝胶上持续存在的部分变性二级结构。
