5ZEY

M. smegmatis Trans-translation state 70S ribosome

Summary for 5ZEY

• Entry DOI: 10.2210/pdb5zey/pdb
• EMDB information: 6925
• Descriptor: tmRNA, A-tRNAfMet, SsrA-binding protein (3 entities in total)
• Functional Keywords: trans-translating state, rna binding protein-rna complex, rna binding protein/rna
• Biological source: Mycobacterium smegmatis (strain ATCC 700084 / mc(2)155); More
• Total number of polymer chains: 3
• Total formula weight: 162320.32

Authors

Mishra, S.,Ahmed, T.,Tyagi, A.,Shi, J.,Bhushan, S. (deposition date: 2018-02-28, release date: 2018-09-26, Last modification date: 2024-03-27)

Primary citation

Mishra, S.,Ahmed, T.,Tyagi, A.,Shi, J.,Bhushan, S.
Structures of Mycobacterium smegmatis 70S ribosomes in complex with HPF, tmRNA, and P-tRNA.
Sci Rep, 8:13587-13587, 2018

PubMed Abstract: Ribosomes 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 Å, 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.

PubMed: 30206241
DOI: 10.1038/s41598-018-31850-3

Experimental method

ELECTRON MICROSCOPY (12.5 Å)