4V1A

Structure of the large subunit of the mammalian mitoribosome, part 2 of 2

Summary for 4V1A

• Entry DOI: 10.2210/pdb4v1a/pdb
• Related: 4V19
• EMDB information: 2787
• Descriptor: MITORIBOSOMAL PROTEIN ML37, MRPL37, MITORIBOSOMAL PROTEIN ML46, MRPL46, MITORIBOSOMAL PROTEIN ML48, MRPL48, ... (24 entities in total)
• Functional Keywords: ribosome, translation, large ribosomal subunit, mitoribosome, mammalian mitochondrial ribosome, cryo-em
• Biological source: SUS SCROFA (PIG); More
• Total number of polymer chains: 23
• Total formula weight: 563888.66

Authors

Greber, B.J.,Boehringer, D.,Leibundgut, M.,Bieri, P.,Leitner, A.,Schmitz, N.,Aebersold, R.,Ban, N. (deposition date: 2014-09-25, release date: 2014-10-08, Last modification date: 2024-05-08)

Primary citation

Greber, B.J.,Boehringer, D.,Leibundgut, M.,Bieri, P.,Leitner, A.,Schmitz, N.,Aebersold, R.,Ban, N.
The Complete Structure of the Large Subunit of the Mammalian Mitochondrial Ribosome
Nature, 515:283-, 2014

PubMed 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 Å 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 Å 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.

PubMed: 25271403
DOI: 10.1038/NATURE13895

Experimental method

ELECTRON MICROSCOPY (3.4 Å)