4V4W

Structure of a SecM-stalled E. coli ribosome complex obtained by fitting atomic models for RNA and protein components into cryo-EM map EMD-1143

This is a non-PDB format compatible entry.

Summary for 4V4W

• Entry DOI: 10.2210/pdb4v4w/pdb
• Related: 2GY9 2GYA 2GYC
• EMDB information: 1143
• Descriptor: 16S ribosomal RNA, 30S ribosomal subunit protein S9, 30S ribosomal subunit protein S10, ... (49 entities in total)
• Functional Keywords: secm; nascent chain; signal transduction; rna world; polypeptide exit tunnel; translocation; ribosome; elongation arrest; protein-conducting channel, ribosome
• Biological source: Escherichia coli; More
• Total number of polymer chains: 52
• Total formula weight: 2102332.43

Authors

Mitra, K.,Frank, J. (deposition date: 2006-05-09, release date: 2014-07-09, Last modification date: 2024-02-28)

Primary citation

Mitra, K.,Schaffitzel, C.,Fabiola, F.,Chapman, M.S.,Ban, N.,Frank, J.
Elongation arrest by SecM via a cascade of ribosomal RNA rearrangements
Mol.Cell, 22:533-543, 2006

PubMed Abstract: In E. coli, the SecM nascent polypeptide causes elongation arrest, while interacting with 23S RNA bases A2058 and A749-753 in the exit tunnel of the large ribosomal subunit. We compared atomic models fitted by real-space refinement into cryo-electron microscopy reconstructions of a pretranslocational and SecM-stalled E. coli ribosome complex. A cascade of RNA rearrangements propagates from the exit tunnel throughout the large subunit, affecting intersubunit bridges and tRNA positions, which in turn reorient small subunit RNA elements. Elongation arrest could result from the inhibition of mRNA.(tRNAs) translocation, E site tRNA egress, and perhaps translation factor activation at the GTPase-associated center. Our study suggests that the specific secondary and tertiary arrangement of ribosomal RNA provides the basis for internal signal transduction within the ribosome. Thus, the ribosome may itself have the ability to regulate its progression through translation by modulating its structure and consequently its receptivity to activation by cofactors.

PubMed: 16713583
DOI: 10.1016/j.molcel.2006.05.003

Experimental method

ELECTRON MICROSCOPY (15 Å)