Paulsen H, Robertson J M, Wintermeyer W
Nucleic Acids Res. 1982 Apr 24;10(8):2651-63. doi: 10.1093/nar/10.8.2651.
The complexes of N-AcPhe-tRNAPhe (or non-aminoacylated tRNAPhe) from yeast with 70S ribosomes from E. coli have been studied fluorimetrically utilizing wybutine, the fluorophore naturally occurring next to the 3' side of the anticodon, as a probe for conformational changes of the anticodon loop. The fluorescence parameters are very similar for tRNA bound to both ribosomal sites, thus excluding an appreciable conformational change of the anticodon loop upon translocation. The spectral change observed upon binding of tRNAPhe to the P site even in the absence of poly(U) is similar to the one brought about by binding of poly(U) alone to the tRNA. This effect may be due to a hydrophobic binding site of the anticodon loop or to a conformational change of the loop induced by binding interactions of various tRNA sites including the anticodon.
利用反密码子3'侧天然存在的荧光团怀丁碱作为反密码子环构象变化的探针,通过荧光分析法研究了来自酵母的N-乙酰苯丙氨酰-tRNA苯丙氨酸(或非氨酰化tRNA苯丙氨酸)与来自大肠杆菌的70S核糖体形成的复合物。与结合到两个核糖体位点的tRNA相比,荧光参数非常相似,因此排除了转位时反密码子环发生明显构象变化的可能性。即使在没有聚尿苷酸(poly(U))的情况下,当tRNA苯丙氨酸结合到P位点时观察到的光谱变化与单独将聚尿苷酸结合到tRNA所引起的光谱变化相似。这种效应可能是由于反密码子环的疏水结合位点,或者是由于包括反密码子在内的各种tRNA位点的结合相互作用诱导的环构象变化。