Horowitz J, Ofengand J, Daniel W E, Cohn M
J Biol Chem. 1977 Jun 25;252(12):4418-20.
The 19F NMR spectrum of Escherichia coli tRNA1Val in which [5-19F]uridine replaces 93% of all uridine and uridine-derived residues has been examined at 93.6 and 235 MHz. The resolution of 11 peaks and visibility of two additional shoulders at either frequency for the 14 FUra residues in the molecule attests to the excellence of 19F as a probe for the structure of tRNA1Val in solution. No significant gain in resolution was attained at the higher frequency. A comparison of the relative areas in the different regions of the 19F spectrum of mixed [FUra]tRNAs with that of [FUra]tRNA1Val suggests that the three single resonances at lowest field in the region 86.5 to 88.5 ppm upfield from trifluoroacetate correspond to the three invariant bases which form tertiary hydrogen bonds in all tRNAs, namely, 8 (U or s4U), 54 (T), and 55 (phi) in unsubstituted tRNAs.
已经在93.6和235兆赫下检测了大肠杆菌tRNA1Val的19F核磁共振谱，其中[5-19F]尿苷取代了所有尿苷和尿苷衍生残基的93%。分子中14个氟尿嘧啶残基在这两个频率下的11个峰的分辨率以及另外两个峰肩的可见性证明19F作为溶液中tRNA1Val结构的探针非常出色。在较高频率下分辨率没有显著提高。混合[氟尿嘧啶]tRNA的19F谱不同区域的相对面积与[氟尿嘧啶]tRNA1Val的相对面积比较表明，在距三氟乙酸86.5至88.5 ppm高场区域中最低场的三个单共振峰对应于在所有tRNA中形成三级氢键的三个不变碱基，即在未取代的tRNA中的8（U或s4U）、54（T）和55（φ）。
