2J28

MODEL OF E. COLI SRP BOUND TO 70S RNCS

Summary for 2J28

• Entry DOI: 10.2210/pdb2j28/pdb
• Related: 1DUL 1HQ1 1P85 1P86 2AW4 2AWB
• EMDB information: 1261 1262
• Descriptor: 50S ribosomal protein L32, 23S RIBOSOMAL RNA, 50S ribosomal protein L2, ... (36 entities in total)
• Functional Keywords: ribosome, protein-rna complex, signal recognition particle
• Biological source: Escherichia coli (strain K12); More
• Total number of polymer chains: 34
• Total formula weight: 1428775.95

Authors

Halic, M.,Blau, M.,Becker, T.,Mielke, T.,Pool, M.R.,Wild, K.,Sinning, I.,Beckmann, R. (deposition date: 2006-08-16, release date: 2006-11-08, Last modification date: 2024-05-08)

Primary citation

Halic, M.,Blau, M.,Becker, T.,Mielke, T.,Pool, M.R.,Wild, K.,Sinning, I.,Beckmann, R.
Following the Signal Sequence from Ribosomal Tunnel Exit to Signal Recognition Particle
Nature, 444:508-511, 2006

PubMed Abstract: Membrane and secretory proteins can be co-translationally inserted into or translocated across the membrane. This process is dependent on signal sequence recognition on the ribosome by the signal recognition particle (SRP), which results in targeting of the ribosome-nascent-chain complex to the protein-conducting channel at the membrane. Here we present an ensemble of structures at subnanometre resolution, revealing the signal sequence both at the ribosomal tunnel exit and in the bacterial and eukaryotic ribosome-SRP complexes. Molecular details of signal sequence interaction in both prokaryotic and eukaryotic complexes were obtained by fitting high-resolution molecular models. The signal sequence is presented at the ribosomal tunnel exit in an exposed position ready for accommodation in the hydrophobic groove of the rearranged SRP54 M domain. Upon ribosome binding, the SRP54 NG domain also undergoes a conformational rearrangement, priming it for the subsequent docking reaction with the NG domain of the SRP receptor. These findings provide the structural basis for improving our understanding of the early steps of co-translational protein sorting.

PubMed: 17086193
DOI: 10.1038/nature05326

Experimental method

ELECTRON MICROSCOPY (9.5 Å)