8QOA

Structure of SecM-stalled Escherichia coli 70S ribosome

This is a non-PDB format compatible entry.

Summary for 8QOA

• Entry DOI: 10.2210/pdb8qoa/pdb
• EMDB information: 18534
• Descriptor: Large ribosomal subunit protein bL33, 30S ribosomal protein S6, fully modified isoform, 30S ribosomal protein S7, ... (62 entities in total)
• Functional Keywords: secm, src, stalling, arrest peptide, arrest motive, stalling motive, stalled ribosome complex, seca, secretion monitor, leader peptide, translation, ribosome
• Biological source: Escherichia coli BW25113; More
• Total number of polymer chains: 57
• Total formula weight: 2209380.65

Authors

Gersteuer, F.,Morici, M.,Wilson, D.N. (deposition date: 2023-09-28, release date: 2024-03-20, Last modification date: 2024-04-24)

Primary citation

Gersteuer, F.,Morici, M.,Gabrielli, S.,Fujiwara, K.,Safdari, H.A.,Paternoga, H.,Bock, L.V.,Chiba, S.,Wilson, D.N.
The SecM arrest peptide traps a pre-peptide bond formation state of the ribosome.
Nat Commun, 15:2431-2431, 2024

PubMed Abstract: Nascent polypeptide chains can induce translational stalling to regulate gene expression. This is exemplified by the E. coli secretion monitor (SecM) arrest peptide that induces translational stalling to regulate expression of the downstream encoded SecA, an ATPase that co-operates with the SecYEG translocon to facilitate insertion of proteins into or through the cytoplasmic membrane. Here we present the structure of a ribosome stalled during translation of the full-length E. coli SecM arrest peptide at 2.0 Å resolution. The structure reveals that SecM arrests translation by stabilizing the Pro-tRNA in the A-site, but in a manner that prevents peptide bond formation with the SecM-peptidyl-tRNA in the P-site. By employing molecular dynamic simulations, we also provide insight into how a pulling force on the SecM nascent chain can relieve the SecM-mediated translation arrest. Collectively, the mechanisms determined here for SecM arrest and relief are also likely to be applicable for a variety of other arrest peptides that regulate components of the protein localization machinery identified across a wide range of bacteria lineages.

PubMed: 38503753
DOI: 10.1038/s41467-024-46762-2

Experimental method

ELECTRON MICROSCOPY (2 Å)