title: Targeting and Insertion of Membrane Proteins.
abstract: The insertion and assembly of proteins into the inner membrane of bacteria are crucial for many cellular processes, including cellular respiration, signal transduction, and ion and pH homeostasis. This process requires efficient membrane targeting and insertion of proteins into the lipid bilayer in their correct orientation and proper conformation. Playing center stage in these events are the targeting components, signal recognition particle (SRP) and the SRP receptor FtsY, as well as the insertion components, the Sec translocon and the YidC insertase. Here, we will discuss new insights provided from the recent high-resolution structures of these proteins. In addition, we will review the mechanism by which a variety of proteins with different topologies are inserted into the inner membrane of Gram-negative bacteria. Finally, we report on the energetics of this process and provide information on how membrane insertion occurs in Gram-positive bacteria and Archaea. It should be noted that most of what we know about membrane protein assembly in bacteria is based on studies conducted in Escherichia coli.
authors.affiliation: Institute for Microbiology and Molecular Biology, University of Hohenheim, 70599 Stuttgart, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Kuhn
authors.affiliation: Institute for Biochemistry and Molecular Biology, Faculty of Medicine, Albert-Ludwigs-University of Freiburg, 79104, Freiburg, Germany.
authors.forename: Hans-Georg
authors.initials: HG
authors.lastname: Koch
authors.affiliation: Department of Chemistry, The Ohio State University, Columbus, OH 43210.
authors.forename: Ross E
authors.initials: RE
authors.lastname: Dalbey
mesh_terms: D001105:Archaea / Q000378:metabolism; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006094:Gram-Positive Bacteria / Q000378:metabolism; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D026901:Membrane Transport Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D015394:Molecular Structure; D021381:Protein Transport; D018160:Receptors, Cytoplasmic and Nuclear / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D018000:Receptors, Peptide / Q000235:genetics; D000069816:SEC Translocation Channels; D018271:Signal Recognition Particle / Q000235:genetics / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; C087406:FtsY protein, Bacteria; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D018160:Receptors, Cytoplasmic and Nuclear; D018000:Receptors, Peptide; D000069816:SEC Translocation Channels; D018271:Signal Recognition Particle; C412443:YIDC protein, E coli; C036318:signal peptide receptor