嗜热栖热菌酪氨酸转运核糖核酸（tRNATyr）D环中核苷酸序列的酶促置换及其对氨酰化的影响

Enzymatic replacement of nucleotide sequences in the D-loop of T. utilis tRNATyr and its effect on aminoacylation.

作者信息

Ohyama T, Nishikawa K, Takemura S

出版信息

Nucleic Acids Symp Ser. 1983(12):137-40.

Abstract

An efficient method for replacement of nucleotide sequences in the D-loop of T. utilis tRNATyr has been developed. An abnormal tRNATyr lacking in tetranucleotide D16-D-Gm-G19 in its D-loop has been reconstructed by this method and shown to accept tyrosine to about 55% of the aminoacylation level observed for intact tRNATyr. This suggests that the deleted sequence itself is not essential for recognition by TyrRS but a conformational instability of the tRNA possibly caused by the disruption of tertiary interactions between the D-loop and T psi C-loop might have influenced the forward reaction rate leading to the decreased level of aminoacylation.

摘要

已开发出一种有效方法用于替换嗜热栖热菌tRNATyr D环中的核苷酸序列。通过该方法重建了一种异常的tRNATyr，其D环中缺少四核苷酸D16-D-Gm-G19，并且显示出接受酪氨酸的能力约为完整tRNATyr所观察到的氨酰化水平的55%。这表明缺失的序列本身对于酪氨酰-tRNA合成酶（TyrRS）的识别并非必不可少，但tRNA的构象不稳定性可能是由D环与TψC环之间三级相互作用的破坏所引起，这可能影响了正向反应速率，导致氨酰化水平降低。