7odr
From Proteopedia
State A of the human mitoribosomal large subunit assembly intermediate
Structural highlights
FunctionMASU1_HUMAN May function as a ribosomal silencing factor. Addition to isolated mitochondrial ribosomal subunits partially inhibits translation. Interacts with mitochondrial ribosomal protein L14 (MRPL14), probably blocking formation of intersubunit bridge B8, preventing association of the 28S and 39S ribosomal subunits and the formation of functional ribosomes, thus repressing translation. May also participate in the assembly and/or regulation of the stability of the large subunit of the mitochondrial ribosome.[1] Publication Abstract from PubMedMitochondrial ribosomes are specialized for the synthesis of membrane proteins responsible for oxidative phosphorylation. Mammalian mitoribosomes have diverged considerably from the ancestral bacterial ribosomes and feature dramatically reduced ribosomal RNAs. The structural basis of the mammalian mitochondrial ribosome assembly is currently not well understood. Here we present eight distinct assembly intermediates of the human large mitoribosomal subunit involving seven assembly factors. We discover that the NSUN4-MTERF4 dimer plays a critical role in the process by stabilizing the 16S rRNA in a conformation that exposes the functionally important regions of rRNA for modification by the MRM2 methyltransferase and quality control interactions with the conserved mitochondrial GTPase MTG2 that contacts the sarcin-ricin loop and the immature active site. The successive action of these factors leads to the formation of the peptidyl transferase active site of the mitoribosome and the folding of the surrounding rRNA regions responsible for interactions with tRNAs and the small ribosomal subunit. Stepwise maturation of the peptidyl transferase region of human mitoribosomes.,Lenarcic T, Jaskolowski M, Leibundgut M, Scaiola A, Schonhut T, Saurer M, Lee RG, Rackham O, Filipovska A, Ban N Nat Commun. 2021 Jun 16;12(1):3671. doi: 10.1038/s41467-021-23811-8. PMID:34135320[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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Categories: Homo sapiens | Large Structures | Ban N | Filipovska A | Jaskolowski M | Lee RG | Leibundgut M | Lenarcic T | Rackham O | Saurer M | Scaiola A | Schoenhut T