In vitro cleavage of Drosophila 2S rRNA by M1 RNA.

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.