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Updated: Jan 10, 2026
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Simultaneous Mapping and Quantitation of Ribonucleotides in Human Mitochondrial DNA
Published on: November 14, 2017
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Substrate and enzyme determinants for recognition by human mitochondrial RNase P.
Enxhi Hazisllari1, Danijela Radovanović1, Ursula Toth1
1Center for Anatomy & Cell Biology, Medical University of Vienna, 1090 Vienna, Austria.
Nucleic Acids Research
|November 20, 2025
Summary
Human mitochondrial RNase P (mtRNase P) uniquely processes tRNA precursors, showing increased efficiency with longer 5' extensions. This enzyme utilizes a rigid mechanism for cleavage-site selection, distinguishing it from other RNase P enzymes.
Area of Science:
- Molecular Biology
- Enzymology
- RNA Processing
Background:
- RNase P enzymes are crucial for tRNA maturation, typically recognizing specific tRNA regions.
- Human mitochondrial RNase P (mtRNase P) has a distinct architecture, involving the TRMT10C-SDR5C1 subcomplex to encase the entire tRNA.
Purpose of the Study:
- To kinetically analyze substrate recognition by human mtRNase P.
- To elucidate the unique mechanisms of tRNA precursor processing by mtRNase P.
Main Methods:
- Kinetic analysis of substrate recognition.
- Utilized substrate and protein variants for mtRNase P.
- Investigated the role of the TRMT10C-SDR5C1 subcomplex in processing.
Main Results:
- mtRNase P processing efficiency increases with longer 5' extensions, sharply decreasing at 1 nt.
- mtRNase P employs a more rigid cleavage-site selection mechanism than single-subunit enzymes.
- TRMT10C-SDR5C1 interactions are not essential for processing but are required for PRORP stimulation.
Conclusions:
- Human mtRNase P exhibits unique substrate recognition properties compared to other RNase P enzymes.
- The enzyme's rigid mechanism and dependence on TRMT10C-SDR5C1 highlight its specialized function.
- mtRNase P faces limitations with specific tRNA precursors like D-armless mitochondrial tRNASer(AGY).
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