Kinetics of the processing of the precursor to 4.5 S RNA, a naturally occurring substrate for RNase P from Escherichia coli

J Mol Biol. 1991 Sep 5;221(1):1-5. doi: 10.1016/0022-2836(91)80194-y.

Abstract

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.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Base Sequence
  • Endoribonucleases / metabolism*
  • Escherichia coli / genetics*
  • Escherichia coli / metabolism
  • Escherichia coli Proteins*
  • Kinetics
  • Molecular Sequence Data
  • Nucleic Acid Conformation
  • RNA Precursors / metabolism*
  • RNA Processing, Post-Transcriptional*
  • RNA, Bacterial / metabolism*
  • RNA, Catalytic / metabolism*
  • Ribonuclease P
  • Substrate Specificity

Substances

  • Escherichia coli Proteins
  • RNA Precursors
  • RNA, Bacterial
  • RNA, Catalytic
  • Endoribonucleases
  • Ribonuclease P
  • ribonuclease P, E coli