Kinetics of hyperprocessing reaction of human tyrosine tRNA by ribonuclease P ribozyme from Escherichia coli

Tomoaki Ando, Terumichi Tanaka, Yoshiaki Hori, Yo Kikuchi

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7 Citations (Scopus)

Abstract

Human tyrosine tRNA and fly alanine, histidine, and initiator methionine (RNAs are generally cleavable internally by bacterial ribonuclease P ribozyme. The unusual internal cleavage reaction of tRNA, called hyperprocessing, occurs when the cloverleaf structure of the tRNA molecule is denatured to form a double-hairpin-like structure. The hyperprocessing reaction of these tRNAs requires magnesium ions. We analyzed details of this reaction using human tyrosine tRNA and Escherichia coli RNase P ribozyme. The usual processing reaction occurred efficiently with magnesium at 5 mM, but for the hyperprpocessing reaction, higher concentrations were needed. With such high concentrations, hyperprocessing cleaved both mature tRNA and tRNA precursor as substrates. When mature tRNA was the substrate, the apparent KM was almost the same as in the usual reaction, but kcat, was smaller. These results indicated that the occurrence of hyperprocessing depends on the magnesium ion concentration, and suggested that magnesium ions contribute to the recognition of the shape of the substrate by bacterial RNase P enzymes.

Original languageEnglish
Pages (from-to)1967-1971
Number of pages5
JournalBioscience, Biotechnology and Biochemistry
Volume66
Issue number9
Publication statusPublished - 2002 Sep
Externally publishedYes

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Keywords

  • Escherichia coli
  • Hyperprocessing
  • RNase P
  • tRNA
  • Tyrosine

ASJC Scopus subject areas

  • Food Science
  • Applied Microbiology and Biotechnology
  • Chemistry (miscellaneous)
  • Biochemistry, Genetics and Molecular Biology(all)
  • Biochemistry
  • Biotechnology
  • Bioengineering

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