5UQ7

70S ribosome complex with dnaX mRNA stemloop and E-site tRNA ("in" conformation)

This is a non-PDB format compatible entry.

Summary for 5UQ7

• Entry DOI: 10.2210/pdb5uq7/pdb
• Related: 5UQ8
• EMDB information: 8596 8597
• Descriptor: 23S rRNA, 50S ribosomal protein L14, 50S ribosomal protein L15, ... (58 entities in total)
• Functional Keywords: 70s ribosome, dnax, stem-loop, structured mrna, -1 programmed frameshifting, e site, ribosome
• Biological source: Thermus thermophilus (strain HB8 / ATCC 27634 / DSM 579); More
• Total number of polymer chains: 56
• Total formula weight: 2231460.70

Authors

Zhang, Y.,Hong, S.,Skiniotis, G.,Dunham, C.M. (deposition date: 2017-02-07, release date: 2018-03-07, Last modification date: 2025-03-19)

Primary citation

Zhang, Y.,Hong, S.,Ruangprasert, A.,Skiniotis, G.,Dunham, C.M.
Alternative Mode of E-Site tRNA Binding in the Presence of a Downstream mRNA Stem Loop at the Entrance Channel.
Structure, 26:437-445.e3, 2018

PubMed Abstract: Structured mRNAs positioned downstream of the ribosomal decoding center alter gene expression by slowing protein synthesis. Here, we solved the cryo-EM structure of the bacterial ribosome bound to an mRNA containing a 3' stem loop that regulates translation. Unexpectedly, the E-site tRNA adopts two distinct orientations. In the first structure, normal interactions with the 50S and 30S E site are observed. However, in the second structure, although the E-site tRNA makes normal interactions with the 50S E site, its anticodon stem loop moves ∼54 Å away from the 30S E site to interact with the 30S head domain and 50S uL5. This position of the E-site tRNA causes the uL1 stalk to adopt a more open conformation that likely represents an intermediate state during E-site tRNA dissociation. These results suggest that structured mRNAs at the entrance channel restrict 30S subunit movement required during translation to slow E-site tRNA dissociation.

PubMed: 29456023
DOI: 10.1016/j.str.2018.01.013

Experimental method

ELECTRON MICROSCOPY (3.5 Å)