3jd5 | pdb_00003jd5
Cryo-EM structure of the small subunit of the mammalian mitochondrial ribosome
Structural highlights
Function[RT34_BOVIN] Required for mitochondrial translation, plays a role in maintaining the stability of the small ribosomal subunit and the 12S rRNA that are required for mitoribosome formation.[UniProtKB:Q9JIK9] [PTCD3_BOVIN] Mitochondrial RNA-binding protein that has a role in mitochondrial translation. [RT29_BOVIN] Involved in mediating interferon-gamma-induced cell death. Publication Abstract from PubMedThe mammalian mitochondrial ribosomes (mitoribosomes) are responsible for synthesizing 13 membrane proteins that form essential components of the complexes involved in oxidative phosphorylation or ATP generation for the eukaryotic cell. The mammalian 55S mitoribosome contains significantly smaller rRNAs and a large mass of mitochondrial ribosomal proteins (MRPs), including large mito-specific amino acid extensions and insertions in MRPs that are homologous to bacterial ribosomal proteins and an additional 35 mito-specific MRPs. Here we present the cryo-EM structure analysis of the small (28S) subunit (SSU) of the 55S mitoribosome. We find that the mito-specific extensions in homologous MRPs generally are involved in inter-MRP contacts and in contacts with mito-specific MRPs, suggesting a stepwise evolution of the current architecture of the mitoribosome. Although most of the mito-specific MRPs and extensions of homologous MRPs are situated on the peripheral regions, they also contribute significantly to the formation of linings of the mRNA and tRNA paths, suggesting a tailor-made structural organization of the mito-SSU for the recruitment of mito-specific mRNAs, most of which do not possess a 5' leader sequence. In addition, docking of previously published coordinates of the large (39S) subunit (LSU) into the cryo-EM map of the 55S mitoribosome reveals that mito-specific MRPs of both the SSU and LSU are involved directly in the formation of six of the 15 intersubunit bridges. Cryo-EM structure of the small subunit of the mammalian mitochondrial ribosome.,Kaushal PS, Sharma MR, Booth TM, Haque EM, Tung CS, Sanbonmatsu KY, Spremulli LL, Agrawal RK Proc Natl Acad Sci U S A. 2014 May 20;111(20):7284-9. doi:, 10.1073/pnas.1401657111. Epub 2014 May 5. PMID:24799711[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
| ||||||||||||||
