title: FtsY, the bacterial signal-recognition particle receptor, interacts functionally and physically with the SecYEG translocon.
abstract: Co-translational membrane targeting of proteins by the bacterial signal-recognition particle (SRP) requires the specific interaction of the SRP-ribosome nascent chain complex with FtsY, the bacterial SRP receptor (SR). FtsY is homologous to the SRalpha-subunit of the eukaryotic SR, which is tethered to the endoplasmic-reticulum membrane by its interaction with the integral SRbeta-subunit. In contrast to SRalpha, FtsY is partly membrane associated and partly located in the cytosol. However, the mechanisms by which FtsY associates with the membrane are unclear. No gene encoding an SRbeta homologue has been found in bacterial genomes, and the presence of an FtsY-specific membrane receptor has not been shown so far. We now provide evidence for the direct interaction between FtsY and the SecY translocon. This interaction offers an explanation of how the bacterial SRP cycle is regulated in response to available translocation channels.
authors.affiliation: Institute for Biochemistry & Molecular Biology, University Freiburg, Hermann-Herder-Strasse 7, 79104 Freiburg, Germany.
authors.forename: Sandra
authors.initials: S
authors.lastname: Angelini
authors.forename: Sandra
authors.initials: S
authors.lastname: Deitermann
authors.forename: Hans-Georg
authors.initials: HG
authors.lastname: Koch
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D018160:Receptors, Cytoplasmic and Nuclear / Q000235:genetics / Q000378:metabolism*; D000069816:SEC Translocation Channels; D018271:Signal Recognition Particle / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; C087406:FtsY protein, Bacteria; D018160:Receptors, Cytoplasmic and Nuclear; D000069816:SEC Translocation Channels; C057841:SecY protein, E coli; D018271:Signal Recognition Particle