caa a22 4500 528785699 20190713030954.0 cr unu---uuuuu 180924s2016 xx s 000 0 eng 10.3929/ethz-b-000112526 doi 10.1038/ncomms10471 doi (ETHRESEARCH)oai:www.research-collection.ethz.ch:20.500.11850/112526 Structures of the E. coli translating ribosome with SRP and its receptor and with the translocon [Elektronische Daten] [Ahmad Jomaa, id_orcid 0000-0002-4786-934X, Daniel Boehringer, Marc Leibundgut, Nenad Ban] Nat Commun Open access ethresearch Co-translational protein targeting to membranes is a universally conserved process. Central steps include cargo recognition by the signal recognition particle and handover to the Sec translocon. Here we present snapshots of key co-translational-targeting complexes solved by cryo-electron microscopy at near-atomic resolution, establishing the molecular contacts between the Escherichia coli translating ribosome, the signal recognition particle and the translocon. Our results reveal the conformational changes that regulate the latching of the signal sequence, the release of the heterodimeric domains of the signal recognition particle and its receptor, and the handover of the signal sequence to the translocon. We also observe that the signal recognition particle and the translocon insert-specific structural elements into the ribosomal tunnel to remodel it, possibly to sense nascent chains. Our work provides structural evidence for a conformational state of the signal recognition particle and its receptor primed for translocon binding to the ribosome-nascent chain complex. Creative Commons Attribution 4.0 International http://creativecommons.org/licenses/by/4.0 ethresearch Jomaa Ahmad joint author id_orcid 0000-0002-4786-934X joint author Boehringer Daniel joint author Leibundgut Marc joint author Ban Nenad joint author Nature Communications London : Nature Publ. Group 7, p. 10471 2041-1723 http://hdl.handle.net/20.500.11850/112526 text/html WWW-Backlink auf das Repository (Open access) 1 Journal Article ethresearch ETHRESEARCH 856 40 http://hdl.handle.net/20.500.11850/112526 text/html WWW-Backlink auf das Repository (Open access) ETHRESEARCH 700 1- Jomaa Ahmad joint author ETHRESEARCH 700 -- id_orcid 0000-0002-4786-934X joint author ETHRESEARCH 700 1- Boehringer Daniel joint author ETHRESEARCH 700 1- Leibundgut Marc joint author ETHRESEARCH 700 1- Ban Nenad joint author ETHRESEARCH 773 0- Nature Communications London : Nature Publ. Group 7, p. 10471 2041-1723 BK010053 XK010053 XK010000 ETHRESEARCH ETHRESEARCH ETHRESEARCH Journal Article Open access