Kinetics of the processing of the precursor to 4.5 S RNA, a naturally occurring substrate for RNase P from Escherichia coli.
A study was made of the cleavage by M1 RNA and RNase P of a non-tRNA precursor that can serve as a substrate for RNase P from Escherichia coli, namely, the precursor to 4.5 S RNA (p4.5S). The overall efficiency of cleavage of p4.5S by RNase P is similar to that of wild-type tRNA precursors. However, unlike the reaction with wild-type tRNA precursors, the reaction catalyzed by the holoenzyme with p4.5S as substrate has a much lower Km value than that catalyzed by M1 RNA with the same substrate, indicating that the protein subunit plays a crucial role in the recognition of p4.5S. A model hairpin substrate, based on the sequence of p4.5S, is cleaved with greater efficiency than the parent molecule. The 3'-terminal CCC sequence of p4.5 S may be as important for cleavage of this substrate as the 3'-terminal CCA sequence is for cleavage of tRNA precursors.
Peck-Miller
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KA
Department of Biology, Yale University, New Haven, CT 06520.
Altman
S
S
D001483:Base Sequence; D004722:Endoribonucleases / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D029968:Escherichia coli Proteins; D007700:Kinetics; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D012322:RNA Precursors / Q000378:metabolism*; D012323:RNA Processing, Post-Transcriptional; D012329:RNA, Bacterial / Q000378:metabolism*; D016337:RNA, Catalytic / Q000378:metabolism*; D043262:Ribonuclease P; D013379:Substrate Specificity
D029968:Escherichia coli Proteins; D012322:RNA Precursors; D012329:RNA, Bacterial; D016337:RNA, Catalytic; D004722:Endoribonucleases; D043262:Ribonuclease P; C470865:ribonuclease P, E coli