8CBO image
Entry Detail
PDB ID:
8CBO
EMDB ID:
Title:
Structure of human mitochondrial MRPP1-MRPP2 in complex with mitochondrial pre-tRNA-Ile
Biological Source:
Source Organism:
Host Organism:
PDB Version:
Deposition Date:
2023-01-25
Release Date:
2024-06-12
Method Details:
Experimental Method:
Resolution:
3.20 Å
Aggregation State:
PARTICLE
Reconstruction Method:
SINGLE PARTICLE
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:3-hydroxyacyl-CoA dehydrogenase type-2
Chain IDs:A, B, C, D
Chain Length:255
Number of Molecules:4
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Description:tRNA methyltransferase 10 homolog C
Chain IDs:E
Chain Length:211
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polyribonucleotide
Description:Mitochondrial Precursor tRNA-Ile(5,4)
Chain IDs:F (auth: T)
Chain Length:78
Number of Molecules:1
Biological Source:Homo sapiens
Primary Citation
Structural basis for human mitochondrial tRNA maturation.
Nat Commun 15 4683 4683 (2024)
PMID: 38824131 DOI: 10.1038/s41467-024-49132-0

Abstact

The human mitochondrial genome is transcribed into two RNAs, containing mRNAs, rRNAs and tRNAs, all dedicated to produce essential proteins of the respiratory chain. The precise excision of tRNAs by the mitochondrial endoribonucleases (mt-RNase), P and Z, releases all RNA species from the two RNA transcripts. The tRNAs then undergo 3'-CCA addition. In metazoan mitochondria, RNase P is a multi-enzyme assembly that comprises the endoribonuclease PRORP and a tRNA methyltransferase subcomplex. The requirement for this tRNA methyltransferase subcomplex for mt-RNase P cleavage activity, as well as the mechanisms of pre-tRNA 3'-cleavage and 3'-CCA addition, are still poorly understood. Here, we report cryo-EM structures that visualise four steps of mitochondrial tRNA maturation: 5' and 3' tRNA-end processing, methylation and 3'-CCA addition, and explain the defined sequential order of the tRNA processing steps. The methyltransferase subcomplex recognises the pre-tRNA in a distinct mode that can support tRNA-end processing and 3'-CCA addition, likely resulting from an evolutionary adaptation of mitochondrial tRNA maturation complexes to the structurally-fragile mitochondrial tRNAs. This subcomplex can also ensure a tRNA-folding quality-control checkpoint before the sequential docking of the maturation enzymes. Altogether, our study provides detailed molecular insight into RNA-transcript processing and tRNA maturation in human mitochondria.

Legend

Protein

Chemical

Disease

Primary Citation of related structures