title: Structural Dynamics of the YidC:Ribosome Complex during Membrane Protein Biogenesis.
abstract: Members of the YidC/Oxa1/Alb3 family universally facilitate membrane protein biogenesis, via mechanisms that have thus far remained unclear. Here, we investigated two crucial functional aspects: the interaction of YidC with ribosome:nascent chain complexes (RNCs) and the structural dynamics of RNC-bound YidC in nanodiscs. We observed that a fully exposed nascent transmembrane domain (TMD) is required for high-affinity YidC:RNC interactions, while weaker binding may already occur at earlier stages of translation. YidC efficiently catalyzed the membrane insertion of nascent TMDs in both fluid and gel phase membranes. Cryo-electron microscopy and fluorescence analysis revealed a conformational change in YidC upon nascent chain insertion: the essential TMDs 2 and 3 of YidC were tilted, while the amphipathic helix EH1 relocated into the hydrophobic core of the membrane. We suggest that EH1 serves as a mechanical lever, facilitating a coordinated movement of YidC TMDs to trigger the release of nascent chains into the membrane.
authors.affiliation: Gene Center Munich, Department of Biochemistry, Ludwig-Maximilians-University Munich, Feodor-Lynen-Strasse 25, Munich 81377, Germany. Electronic address: kedrov@genzentrum.lmu.de.
authors.forename: Alexej
authors.initials: A
authors.lastname: Kedrov
authors.affiliation: Gene Center Munich, Department of Biochemistry, Ludwig-Maximilians-University Munich, Feodor-Lynen-Strasse 25, Munich 81377, Germany.
authors.forename: Stephan
authors.initials: S
authors.lastname: Wickles
authors.affiliation: Physical Chemistry, Department of Chemistry, Center for Nanoscience (CeNS), the NanoSystems Initiative Munich (NIM), Ludwig-Maximilians-University Munich, Butenandtstrasse 11, Munich 81377, Germany.
authors.forename: Alvaro H
authors.initials: AH
authors.lastname: Crevenna
authors.affiliation: Gene Center Munich, Department of Biochemistry, Ludwig-Maximilians-University Munich, Feodor-Lynen-Strasse 25, Munich 81377, Germany.
authors.forename: Eli O
authors.initials: EO
authors.lastname: van der Sluis
authors.affiliation: Gene Center Munich, Department of Biochemistry, Ludwig-Maximilians-University Munich, Feodor-Lynen-Strasse 25, Munich 81377, Germany.
authors.forename: Robert
authors.initials: R
authors.lastname: Buschauer
authors.affiliation: Gene Center Munich, Department of Biochemistry, Ludwig-Maximilians-University Munich, Feodor-Lynen-Strasse 25, Munich 81377, Germany.
authors.forename: Otto
authors.initials: O
authors.lastname: Berninghausen
authors.affiliation: Physical Chemistry, Department of Chemistry, Center for Nanoscience (CeNS), the NanoSystems Initiative Munich (NIM), Ludwig-Maximilians-University Munich, Butenandtstrasse 11, Munich 81377, Germany; Center for Integrated Protein Science Munich (CiPSM), Ludwig-Maximilians-University, Butenandtstrasse 5-13, Munich 81377, Germany.
authors.forename: Don C
authors.initials: DC
authors.lastname: Lamb
authors.affiliation: Gene Center Munich, Department of Biochemistry, Ludwig-Maximilians-University Munich, Feodor-Lynen-Strasse 25, Munich 81377, Germany; Center for Integrated Protein Science Munich (CiPSM), Ludwig-Maximilians-University, Butenandtstrasse 5-13, Munich 81377, Germany. Electronic address: beckmann@genzentrum.lmu.de.
authors.forename: Roland
authors.initials: R
authors.lastname: Beckmann
mesh_terms: D020285:Cryoelectron Microscopy; D003576:Electron Transport Complex IV / Q000235:genetics / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000235:genetics* / Q000378:metabolism; D057927:Hydrophobic and Hydrophilic Interactions; D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism / Q000648:ultrastructure; D026901:Membrane Transport Proteins / Q000235:genetics* / Q000378:metabolism; D024101:Mitochondrial Proteins / Q000235:genetics / Q000378:metabolism; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding; D014176:Protein Biosynthesis; D012270:Ribosomes / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure
chemical_list: D029968:Escherichia coli Proteins; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D024101:Mitochondrial Proteins; D009687:Nuclear Proteins; C090858:OXA1 protein; C412443:YIDC protein, E coli; D003576:Electron Transport Complex IV
keywords: cryo-electron microscopy; fluorescence correlation spectroscopy; insertase; macromolecular assembly; membrane protein; nanodisc; translocon