title: Role of the Cytosolic Loop C2 and the C Terminus of YidC in Ribosome Binding and Insertion Activity.
abstract: Members of the YidC/Oxa1/Alb3 protein family mediate membrane protein insertion, and this process is initiated by the assembly of YidC·ribosome nascent chain complexes at the inner leaflet of the lipid bilayer. The positively charged C terminus of Escherichia coli YidC plays a significant role in ribosome binding but is not the sole determinant because deletion does not completely abrogate ribosome binding. The positively charged cytosolic loops C1 and C2 of YidC may provide additional docking sites. We performed systematic sequential deletions within these cytosolic domains and studied their effect on the YidC insertase activity and interaction with translation-stalled (programmed) ribosome. Deletions within loop C1 strongly affected the activity of YidC in vivo but did not influence ribosome binding or substrate insertion, whereas loop C2 appeared to be involved in ribosome binding. Combining the latter deletion with the removal of the C terminus of YidC abolished YidC-mediated insertion. We propose that these two regions play an crucial role in the formation and stabilization of an active YidC·ribosome nascent chain complex, allowing for co-translational membrane insertion, whereas loop C1 may be involved in the downstream chaperone activity of YidC or in other protein-protein interactions.
authors.affiliation: From the Molecular Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute and Zernike Institute for Advanced Materials, Nijenborgh 7, 9747 AG Groningen, The Netherlands.
authors.forename: Yanping
authors.initials: Y
authors.lastname: Geng
authors.affiliation: the Gene Center Munich and.
authors.forename: Alexej
authors.initials: A
authors.lastname: Kedrov
authors.affiliation: From the Molecular Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute and Zernike Institute for Advanced Materials, Nijenborgh 7, 9747 AG Groningen, The Netherlands.
authors.forename: Joseph J
authors.initials: JJ
authors.lastname: Caumanns
authors.affiliation: the Physical Chemistry, Department for Chemistry, Center for Nanoscience, the NanoSystems Initiative Munich and the Center for Integrated Protein Science Munich, Ludwig-Maximilians-University, 81377 Munich, Germany.
authors.forename: Alvaro H
authors.initials: AH
authors.lastname: Crevenna
authors.affiliation: the Physical Chemistry, Department for Chemistry, Center for Nanoscience, the NanoSystems Initiative Munich and the Center for Integrated Protein Science Munich, Ludwig-Maximilians-University, 81377 Munich, Germany.
authors.forename: Don C
authors.initials: DC
authors.lastname: Lamb
authors.affiliation: the Gene Center Munich and.
authors.forename: Roland
authors.initials: R
authors.lastname: Beckmann
authors.affiliation: From the Molecular Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute and Zernike Institute for Advanced Materials, Nijenborgh 7, 9747 AG Groningen, The Netherlands, a.j.m.driessen@rug.nl.
authors.forename: Arnold J M
authors.initials: AJ
authors.lastname: Driessen
mesh_terms: D003600:Cytosol / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D005798:Genes, Bacterial; D005816:Genetic Complementation Test; D014644:Genetic Variation; D026901:Membrane Transport Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D008958:Models, Molecular; D009245:NADH Dehydrogenase / Q000378:metabolism; D011485:Protein Binding; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012270:Ribosomes / Q000378:metabolism*; D017384:Sequence Deletion
chemical_list: D029968:Escherichia coli Proteins; D026901:Membrane Transport Proteins; C098483:NADH dehydrogenase subunit 4; D011994:Recombinant Proteins; C412443:YIDC protein, E coli; D009245:NADH Dehydrogenase
keywords: bacteria; membrane biogenesis; membrane biophysics; membrane enzyme; membrane function