5zet
M. smegmatis P/P state 50S ribosomal subunit
Structural highlights
FunctionRL2_MYCS2 One of the primary rRNA binding proteins. Required for association of the 30S and 50S subunits to form the 70S ribosome, for tRNA binding and peptide bond formation. It has been suggested to have peptidyltransferase activity; this is somewhat controversial. Makes several contacts with the 16S rRNA in the 70S ribosome. Publication Abstract from PubMedRibosomes are the dynamic protein synthesis machineries of the cell. They may exist in different functional states in the cell. Therefore, it is essential to have structural information on these different functional states of ribosomes to understand their mechanism of action. Here, we present single particle cryo-EM reconstructions of the Mycobacterium smegmatis 70S ribosomes in the hibernating state (with HPF), trans-translating state (with tmRNA), and the P/P state (with P-tRNA) resolved to 4.1, 12.5, and 3.4 A, respectively. A comparison of the P/P state with the hibernating state provides possible functional insights about the Mycobacteria-specific helix H54a rRNA segment. Interestingly, densities for all the four OB domains of bS1 protein is visible in the hibernating 70S ribosome displaying the molecular details of bS1-70S interactions. Our structural data shows a Mycobacteria-specific H54a-bS1 interaction which seems to prevent subunit dissociation and degradation during hibernation without the formation of 100S dimer. This indicates a new role of bS1 protein in 70S protection during hibernation in Mycobacteria in addition to its conserved function during translation initiation. Structures of Mycobacterium smegmatis 70S ribosomes in complex with HPF, tmRNA, and P-tRNA.,Mishra S, Ahmed T, Tyagi A, Shi J, Bhushan S Sci Rep. 2018 Sep 11;8(1):13587. doi: 10.1038/s41598-018-31850-3. PMID:30206241[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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