Abstract
A ribonuclease P-like activity was partially purified from HeLa cell mitochondria by DEAE-cellulose and octyl-Sepharose chromatography. RNase P-like activity can be quantitatively recovered from intact mitochondrial preparations treated with micrococcal nuclease, strongly suggesting that the enzyme is localized within the organelles. Mitochondrial RNase P (mt-RNase P) cleaves the precursor to Escherichia coli suppressor tRNA(Tyr) at the same site as E. coli RNase P, producing the mature 5'-end of tRNA(Tyr). The sensitivity of mtRNase P to pretreatment with nucleases or Pronase indicates that the enzyme has essential RNA and protein components. Although the ionic requirements of mtRNase P are similar to those of the RNase P activity isolated from the post-mitochondrial cytosol fraction, the chromatographic properties of mtRNase P are distinct. Mitochondrial RNase P is probably a part of the mitochondrial RNA processing machinery of mammalian mitochondria, being responsible for the endonucleolytic cleavage of the RNA transcripts at the 5'-side of the tRNA sequences.
Original language | English (US) |
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Pages (from-to) | 5942-5949 |
Number of pages | 8 |
Journal | Journal of Biological Chemistry |
Volume | 260 |
Issue number | 10 |
State | Published - 1985 |
Externally published | Yes |
ASJC Scopus subject areas
- Biochemistry
- Molecular Biology
- Cell Biology