EMD-23114
Cryo-EM structure of the human 55S mitoribosome in complex with RRFmt and EF-G2mt
EMD-23114
Single-particle3.49 Å
![EMD-23114](https://www.ebi.ac.uk/emdb/images/entry/EMD-23114/400_23114.gif)
Map released: 12/05/2021
Last modified: 01/12/2021
Sample Organism:
Homo sapiens
Sample: 55S Mitochondrial Ribosome, mtEFG2, mtRRF
Raw data: EMPIAR-10703
Deposition Authors: Agrawal E, Koripella R
Sample: 55S Mitochondrial Ribosome, mtEFG2, mtRRF
Raw data: EMPIAR-10703
Deposition Authors: Agrawal E, Koripella R
Distinct mechanisms of the human mitoribosome recycling and antibiotic resistance.
Koripella RK
,
Deep A
,
Agrawal EK,
Keshavan P
,
Banavali NK
,
Agrawal RK
(2021) Nat Commun , 12 , 3607 - 3607
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![](http://www.ebi.ac.uk/web_guidelines/images/logos/orcid/orcid_16x16.png)
(2021) Nat Commun , 12 , 3607 - 3607
Abstract:
Ribosomes are recycled for a new round of translation initiation by dissociation of ribosomal subunits, messenger RNA and transfer RNA from their translational post-termination complex. Here we present cryo-EM structures of the human 55S mitochondrial ribosome (mitoribosome) and the mitoribosomal large 39S subunit in complex with mitoribosome recycling factor (RRFmt) and a recycling-specific homolog of elongation factor G (EF-G2mt). These structures clarify an unusual role of a mitochondria-specific segment of RRFmt, identify the structural distinctions that confer functional specificity to EF-G2mt, and show that the deacylated tRNA remains with the dissociated 39S subunit, suggesting a distinct sequence of events in mitoribosome recycling. Furthermore, biochemical and structural analyses reveal that the molecular mechanism of antibiotic fusidic acid resistance for EF-G2mt is markedly different from that of mitochondrial elongation factor EF-G1mt, suggesting that the two human EF-Gmts have evolved diversely to negate the effect of a bacterial antibiotic.
Ribosomes are recycled for a new round of translation initiation by dissociation of ribosomal subunits, messenger RNA and transfer RNA from their translational post-termination complex. Here we present cryo-EM structures of the human 55S mitochondrial ribosome (mitoribosome) and the mitoribosomal large 39S subunit in complex with mitoribosome recycling factor (RRFmt) and a recycling-specific homolog of elongation factor G (EF-G2mt). These structures clarify an unusual role of a mitochondria-specific segment of RRFmt, identify the structural distinctions that confer functional specificity to EF-G2mt, and show that the deacylated tRNA remains with the dissociated 39S subunit, suggesting a distinct sequence of events in mitoribosome recycling. Furthermore, biochemical and structural analyses reveal that the molecular mechanism of antibiotic fusidic acid resistance for EF-G2mt is markedly different from that of mitochondrial elongation factor EF-G1mt, suggesting that the two human EF-Gmts have evolved diversely to negate the effect of a bacterial antibiotic.