Freier S M, Tinoco I
Biochemistry. 1975 Jul 29;14(15):3310-4. doi: 10.1021/bi00686a004.
Oligoribonucleotide binding to baker's yeast initiator tRNA was measured by equilibrium dialysis in order to determine which regions of the tRNA were free to bind complementary oligomers and which were involved in secondary and tertiary structure. Association constants of trinucleoside diphosphates and tetranucleoside triphophates complementary to the single-stranded regions of the cloverleaf structure of yeast tRNAfMet were measured at o degrees in 1.0 M NaCl, and 0.01 M MgCl2. The only regions of the tRNA whose complementary oligomers bound to the tRNA were the amino acid acceptor end and the five nucleotides at the 5' end of the anticodon loop. These results differ from those for the other tRNAs studied by this technique; usually oligomers complementary to the dihydrouracil loop bind to the tRNA. The sequence of yeast tRNAfMet and other eucaryotic initiators is unusual. The "TpsiC loop" contains the sequence A-U-C instead of T-psi-C, yet the binding pattern to the THE TpsiC LOOP IS LIKE THAT FOR OTHER TRNAs; no oligomers bind.
通过平衡透析法测定了寡核糖核苷酸与面包酵母起始tRNA的结合情况，以确定tRNA的哪些区域可自由结合互补寡聚物，以及哪些区域参与二级和三级结构。在0℃、1.0M NaCl和0.01M MgCl₂条件下，测定了与酵母tRNAfMet三叶草结构单链区域互补的三核苷二磷酸和四核苷三磷酸的缔合常数。tRNA中其互补寡聚物能与tRNA结合的唯一区域是氨基酸接受末端和反密码子环5′端的五个核苷酸。这些结果与用该技术研究的其他tRNA的结果不同；通常与二氢尿嘧啶环互补的寡聚物会与tRNA结合。酵母tRNAfMet和其他真核起始tRNA的序列不同寻常。“TψC环”包含A-U-C序列而非T-ψ-C，但与TψC环的结合模式与其他tRNA相同；没有寡聚物结合。
