3BBX

The Hsp15 protein fitted into the low resolution Cryo-EM map of the 50S.nc-tRNA.Hsp15 complex

Summary for 3BBX

• Entry DOI: 10.2210/pdb3bbx/pdb
• Related: 2AW4 3BBU 3BBV
• EMDB information: 1455
• Descriptor: 5S ribosomal RNA, 50S ribosomal protein L13, 50S ribosomal protein L14, ... (32 entities in total)
• Functional Keywords: ribosomal complex, large subunit, 50s rescue stalled ribosome, ribosome
• Biological source: Escherichia coli; More
• Total number of polymer chains: 30
• Total formula weight: 1342883.75

Authors

Jiang, L.,Abrahams, J.P. (deposition date: 2007-11-11, release date: 2008-10-21, Last modification date: 2024-02-21)

Primary citation

Jiang, L.,Schaffitzel, C.,Bingel-Erlenmeyer, R.,Ban, N.,Korber, P.,Koning, R.I.,de Geus, D.C.,Plaisier, J.R.,Abrahams, J.P.
Recycling of Aborted Ribosomal 50S Subunit-Nascent Chain-tRNA Complexes by the Heat Shock Protein Hsp15.
J.Mol.Biol., 386:1357-1367, 2009

PubMed Abstract: When heat shock prematurely dissociates a translating bacterial ribosome, its 50S subunit is prevented from reinitiating protein synthesis by tRNA covalently linked to the unfinished protein chain that remains threaded through the exit tunnel. Hsp15, a highly upregulated bacterial heat shock protein, reactivates such dead-end complexes. Here, we show with cryo-electron microscopy reconstructions and functional assays that Hsp15 translocates the tRNA moiety from the A site to the P site of stalled 50S subunits. By stabilizing the tRNA in the P site, Hsp15 indirectly frees up the A site, allowing a release factor to land there and cleave off the tRNA. Such a release factor must be stop codon independent, suggesting a possible role for a poorly characterized class of putative release factors that are upregulated by cellular stress, lack a codon recognition domain and are conserved in eukaryotes.

PubMed: 19013177
DOI: 10.1016/j.jmb.2008.10.079

Experimental method

ELECTRON MICROSCOPY (10 Å)