7a5k
From Proteopedia
Structure of the human mitoribosome in the post translocation state bound to mtEF-G1
Structural highlights
DiseaseEFGM_HUMAN Hepatoencephalopathy due to combined oxidative phosphorylation defect type 1. The disease is caused by variants affecting the gene represented in this entry. FunctionEFGM_HUMAN Mitochondrial GTPase that catalyzes the GTP-dependent ribosomal translocation step during translation elongation. During this step, the ribosome changes from the pre-translocational (PRE) to the post-translocational (POST) state as the newly formed A-site-bound peptidyl-tRNA and P-site-bound deacylated tRNA move to the P and E sites, respectively. Catalyzes the coordinated movement of the two tRNA molecules, the mRNA and conformational changes in the ribosome. Does not mediate the disassembly of ribosomes from messenger RNA at the termination of mitochondrial protein biosynthesis.[HAMAP-Rule:MF_03061][1] Publication Abstract from PubMedThe human mitochondrial ribosome (mitoribosome) and associated proteins regulate the synthesis of 13 essential subunits of the oxidative phosphorylation complexes. We report the discovery of a mitoribosome-associated quality control pathway that responds to interruptions during elongation, and we present structures at 3.1- to 3.3-angstrom resolution of mitoribosomal large subunits trapped during ribosome rescue. Release factor homolog C12orf65 (mtRF-R) and RNA binding protein C6orf203 (MTRES1) eject the nascent chain and peptidyl transfer RNA (tRNA), respectively, from stalled ribosomes. Recruitment of mitoribosome biogenesis factors to these quality control intermediates suggests additional roles for these factors during mitoribosome rescue. We also report related cryo-electron microscopy structures (3.7 to 4.4 angstrom resolution) of elongating mitoribosomes bound to tRNAs, nascent polypeptides, the guanosine triphosphatase elongation factors mtEF-Tu and mtEF-G1, and the Oxa1L translocase. Elongational stalling activates mitoribosome-associated quality control.,Desai N, Yang H, Chandrasekaran V, Kazi R, Minczuk M, Ramakrishnan V Science. 2020 Nov 27;370(6520):1105-1110. doi: 10.1126/science.abc7782. PMID:33243891[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
| ||||||||||||||||||
