title: YidC occupies the lateral gate of the SecYEG translocon and is sequentially displaced by a nascent membrane protein.
abstract: Most membrane proteins are co-translationally inserted into the lipid bilayer via the universally conserved SecY complex and they access the lipid phase presumably via a lateral gate in SecY. In bacteria, the lipid transfer of membrane proteins from the SecY channel is assisted by the SecY-associated protein YidC, but details on the SecY-YidC interaction are unknown. By employing an in vivo and in vitro site-directed cross-linking approach, we have mapped the SecY-YidC interface and found YidC in contact with all four transmembrane domains of the lateral gate. This interaction did not require the SecDFYajC complex and was not influenced by SecA binding to SecY. In contrast, ribosomes dissociated the YidC contacts to lateral gate helices 2b and 8. The major contact between YidC and the lateral gate was lost in the presence of ribosome nascent chains and new SecY-YidC contacts appeared. These data demonstrate that the SecY-YidC interaction is influenced by nascent-membrane-induced lateral gate movements.
authors.affiliation: Institut für Biochemie und Molekularbiologie, ZBMZ, 79104 Freiburg, Germany; Fakultät für Biologie, 79104 Freiburg, Germany.
authors.forename: Ilie
authors.initials: I
authors.lastname: Sachelaru
authors.affiliation: Institut für Biochemie und Molekularbiologie, ZBMZ, 79104 Freiburg, Germany; Fakultät für Biologie, 79104 Freiburg, Germany.
authors.forename: Narcis Adrian
authors.initials: NA
authors.lastname: Petriman
authors.affiliation: Institut für Biochemie und Molekularbiologie, ZBMZ, 79104 Freiburg, Germany; Fakultät für Biologie, 79104 Freiburg, Germany; Spemann Graduate School of Biology and Medicine (SGBM), 79104 Freiburg, Germany.
authors.forename: Renuka
authors.initials: R
authors.lastname: Kudva
authors.affiliation: Institut für Biochemie und Molekularbiologie, ZBMZ, 79104 Freiburg, Germany; Fakultät für Biologie, 79104 Freiburg, Germany.
authors.forename: Patrick
authors.initials: P
authors.lastname: Kuhn
authors.affiliation: Institut für Biochemie und Molekularbiologie, ZBMZ, 79104 Freiburg, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Welte
authors.affiliation: Fakultät für Biologie, 79104 Freiburg, Germany.
authors.forename: Bettina
authors.initials: B
authors.lastname: Knapp
authors.affiliation: Fakultät für Biologie, 79104 Freiburg, Germany; BIOSS Centre for Biological Signalling Studies, Zentrum für Biologische Signalstudien, Albert-Ludwigs-Universität Freiburg, 79104 Freiburg, Germany.
authors.forename: Friedel
authors.initials: F
authors.lastname: Drepper
authors.affiliation: Fakultät für Biologie, 79104 Freiburg, Germany; BIOSS Centre for Biological Signalling Studies, Zentrum für Biologische Signalstudien, Albert-Ludwigs-Universität Freiburg, 79104 Freiburg, Germany.
authors.forename: Bettina
authors.initials: B
authors.lastname: Warscheid
authors.affiliation: Institut für Biochemie und Molekularbiologie, ZBMZ, 79104 Freiburg, Germany; Spemann Graduate School of Biology and Medicine (SGBM), 79104 Freiburg, Germany. Electronic address: Hans-Georg.Koch@biochemie.uni-freiburg.de.
authors.forename: Hans-Georg
authors.initials: HG
authors.lastname: Koch
mesh_terms: D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism*; D008051:Lipid Bilayers / Q000378:metabolism*; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D026901:Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism*; D010449:Peptide Mapping; D011485:Protein Binding; D021381:Protein Transport / Q000502:physiology; D000069816:SEC Translocation Channels
chemical_list: D029968:Escherichia coli Proteins; D008051:Lipid Bilayers; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D000069816:SEC Translocation Channels; C065493:SecE protein, E coli; C088616:SecG protein, E coli; C057841:SecY protein, E coli; C412443:YIDC protein, E coli
keywords: Membrane Biogenesis; Membrane Trafficking; Protein Targeting; Secretion; Signal Recognition Particle