Phosphorothioates in pre-tRNAs can change the specificities of RNAses P or reduce the cleavage efficiencies

Biochimie. 1993;75(11):955-62. doi: 10.1016/0300-9084(93)90145-i.

Abstract

Several phosphorothioate-modified E coli and yeast pre-tRNAs were synthesized. If this modification included the phosphodiester at the RNase P cleavage site, two different effects were observed. With some pre-tRNAs the RNase P cleavage efficiency was severely reduced, whereas with other pre-tRNAs a new reaction type for RNase P was observed. Unlike the previously studied base or ribose modifications, phosphorothioates resulted in aberrant cleavages at unmodified phosphodiesters. These new sites could be located in the 5'-flank or in the acceptor stem of the tRNA domain. Modified mutants of E coli pre-tRNA(Tyr) with different base pairs at the RNase P cleavage site were cleaved with reduced efficiencies, but no aberrant products were observed.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Base Composition
  • Base Sequence
  • Endoribonucleases / metabolism*
  • Escherichia coli / genetics
  • Escherichia coli Proteins*
  • Molecular Sequence Data
  • Mutation
  • RNA Precursors / chemistry
  • RNA Precursors / genetics
  • RNA Precursors / metabolism*
  • RNA, Catalytic / metabolism*
  • RNA, Transfer / chemistry
  • RNA, Transfer / genetics
  • RNA, Transfer / metabolism*
  • RNA, Transfer, Amino Acyl / chemistry
  • RNA, Transfer, Amino Acyl / genetics
  • RNA, Transfer, Amino Acyl / metabolism
  • Ribonuclease P
  • Thionucleosides / chemistry
  • Thionucleosides / metabolism*
  • Transcription, Genetic
  • Yeasts / genetics

Substances

  • Escherichia coli Proteins
  • RNA Precursors
  • RNA, Catalytic
  • RNA, Transfer, Amino Acyl
  • Thionucleosides
  • RNA, Transfer
  • Endoribonucleases
  • Ribonuclease P
  • ribonuclease P, E coli