4V19: Structure Of The Large Subunit Of The Mammalian Mitoribosome, Part 1 Of 2

Citation:
Abstract
Mitochondrial ribosomes (mitoribosomes) are extensively modified ribosomes of bacterial descent specialized for the synthesis and insertion of membrane proteins that are critical for energy conversion and ATP production inside mitochondria. Mammalian mitoribosomes, which comprise 39S and 28S subunits, have diverged markedly from the bacterial ribosomes from which they are derived, rendering them unique compared to bacterial, eukaryotic cytosolic and fungal mitochondrial ribosomes. We have previously determined at 4.9 A resolution the architecture of the porcine (Sus scrofa) 39S subunit, which is highly homologous to the human mitoribosomal large subunit. Here we present the complete atomic structure of the porcine 39S large mitoribosomal subunit determined in the context of a stalled translating mitoribosome at 3.4 A resolution by cryo-electron microscopy and chemical crosslinking/mass spectrometry. The structure reveals the locations and the detailed folds of 50 mitoribosomal proteins, shows the highly conserved mitoribosomal peptidyl transferase active site in complex with its substrate transfer RNAs, and defines the path of the nascent chain in mammalian mitoribosomes along their idiosyncratic exit tunnel. Furthermore, we present evidence that a mitochondrial tRNA has become an integral component of the central protuberance of the 39S subunit where it architecturally substitutes for the absence of the 5S ribosomal RNA, a ubiquitous component of all cytoplasmic ribosomes.
PDB ID: 4V19Download
MMDB ID: 123722
PDB Deposition Date: 2014/9/25
Updated in MMDB: 2014/11
Experimental Method:
electron microscopy
Resolution: 3.4  Å
Source Organism:
Similar Structures:
Biological Unit for 4V19: 32-meric; determined by author and by software (PISA)
Molecular Components in 4V19
Label Count Molecule
Proteins (28 molecules)
1
Mitoribosomal Protein Bl27m, Mrpl27
Molecule annotation
1
Mitoribosomal Protein Bl28m, Mrpl28
Molecule annotation
1
Mitoribosomal Protein Ul29m, Mrpl47
Molecule annotation
1
Mitoribosomal Protein Ul30m, Mrpl30
Molecule annotation
1
Mitoribosomal Protein Bl31m, Mrpl55
Molecule annotation
1
Mitoribosomal Protein Bl32m, Mrpl32
Molecule annotation
1
Mitoribosomal Protein Bl33m, Mrpl33
Molecule annotation
1
Mitoribosomal Protein Bl34m, Mrpl34
Molecule annotation
1
Mitoribosomal Protein Bl35m, Mrpl35
Molecule annotation
1
Mitoribosomal Protein Bl36m, Mrpl36
Molecule annotation
1
Mitoribosomal Protein Ul2m, Mrpl2
Molecule annotation
1
Mitoribosomal Protein Ul3m, Mrpl3
Molecule annotation
1
Mitoribosomal Protein Ul4m, Mrpl4
Molecule annotation
1
Mitoribosomal Protein Bl9m, Mrpl9
Molecule annotation
1
Mitoribosomal Protein Ul10m, Mrpl10
Molecule annotation
1
Mitoribosomal Protein Ul11m, Mrpl11
Molecule annotation
1
Mitoribosomal Protein Ul13m, Mrpl13
Molecule annotation
1
Mitoribosomal Protein Ul14m, Mrpl14
Molecule annotation
1
Mitoribosomal Protein Ul15m, Mrpl15
Molecule annotation
1
Mitoribosomal Protein Ul16m, Mrpl16
Molecule annotation
1
Mitoribosomal Protein Bl17m, Mrpl17
Molecule annotation
1
Mitoribosomal Protein Ul18m, Mrpl18
Molecule annotation
1
Mitoribosomal Protein Bl19m, Mrpl19
Molecule annotation
1
Mitoribosomal Protein Bl20m, Mrpl20
Molecule annotation
1
Mitoribosomal Protein Bl21m, Mrpl21
Molecule annotation
1
Mitoribosomal Protein Ul22m, Mrpl22
Molecule annotation
1
Mitoribosomal Protein Ul23m, Mrpl23
Molecule annotation
1
Mitoribosomal Protein Ul24m, Mrpl24
Molecule annotation
Nucleotides(3 molecules)
1
Mitoribosomal 16S rRNA
Molecule annotation
1
Mitoribosomal CP tRNA
Molecule annotation
2
tRNA
Molecule annotation
Chemicals (143 molecules)
1
2
2
141
* Click molecule labels to explore molecular sequence information.

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