Hori Y, Tanaka T, Kikuchi Y
Division of Bioscience and Biotechnology, Department of Ecological Engineering, Toyohashi University of Technology, Tempaku-cho, Toyohashi, Aichi 441-8580, Japan.
Nucleic Acids Symp Ser. 2000(44):93-4. doi: 10.1093/nass/44.1.93.
Drosophila melanogaster initiator methionine tRNA can adopt an alternative conformation in aqueous solution. In this alternative conformation, the aminoacyl- and the anticodon stems of tRNA are unfolded and then these unfolded regions are used to form extended D- and T-stems, resulting in the formation of two tandemly joined stems and loops. This conformational alternation was recognized then cleaved by the catalytic RNA of Escherichia coli ribonuclease P (M1 RNA). The cleavage occurs within the mature sequence of tRNA. This further processing within mature sequence is called hyperprocessing. During the screening experiments of other conformational changeable D. melanogaster tRNAs by M1 RNA, we incidentally found that M1 RNA also hyperprocessed D. melanogaster 2S rRNA. Kinetic analyses of the hyperprocessing reaction of 2S rRNA by M1 RNA revealed that 2S rRNA could form a homodimer.
黑腹果蝇起始甲硫氨酸tRNA在水溶液中可采用另一种构象。在这种构象中，tRNA的氨酰基和反密码子茎展开，然后这些展开区域用于形成延伸的D茎和T茎，从而形成两个串联连接的茎环。这种构象变化随后被大肠杆菌核糖核酸酶P的催化RNA（M1 RNA）识别并切割。切割发生在tRNA的成熟序列内。这种在成熟序列内的进一步加工称为超加工。在通过M1 RNA对其他构象可变的黑腹果蝇tRNA进行筛选实验时，我们偶然发现M1 RNA也对黑腹果蝇2S rRNA进行超加工。对M1 RNA对2S rRNA超加工反应的动力学分析表明，2S rRNA可形成同源二聚体。
