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Updated: Jul 26, 2026

Single Molecule Fluorescence Energy Transfer Study of Ribosome Protein Synthesis
Published on: July 6, 2021
Signal recognition particle receptor exposes the ribosomal translocon binding site
Mario Halic1, Marco Gartmann, Oliver Schlenker
1Institute of Biochemistry, Charité, University Medical School Berlin, Monbijoustrasse 2, 10117 Berlin, Germany.
Abstract:
Signal sequences of secretory and membrane proteins are recognized by the signal recognition particle (SRP) as they emerge from the ribosome. This results in their targeting to the membrane by docking with the SRP receptor, which facilitates transfer of the ribosome to the translocon. Here, we present the 8 angstrom cryo-electron microscopy structure of a "docking complex" consisting of a SRP-bound 80S ribosome and the SRP receptor. Interaction of the SRP receptor with both SRP and the ribosome rearranged the S domain of SRP such that a ribosomal binding site for the translocon, the L23e/L35 site, became exposed, whereas Alu domain-mediated elongation arrest persisted.
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