Identification of a multicomponent complex required for outer membrane biogenesis in Escherichia coli.
Gram-negative bacteria have an outer membrane (OM) that functions as a barrier to protect the cell from toxic compounds such as antibiotics and detergents. The OM is a highly asymmetric bilayer composed of phospholipids, glycolipids, and proteins. Assembly of this essential organelle occurs outside the cytoplasm in an environment that lacks obvious energy sources such as ATP, and the mechanisms involved are poorly understood. We describe the identification of a multiprotein complex required for the assembly of proteins in the OM of Escherichia coli. We also demonstrate genetic interactions between genes encoding components of this protein assembly complex and imp, which encodes a protein involved in the assembly of lipopolysaccharides (LPS) in the OM. These genetic interactions suggest a role for YfgL, one of the lipoprotein components of the protein assembly complex, in a homeostatic control mechanism that coordinates the overall OM assembly process.
Wu
Tao
T
Department of Chemistry, Princeton University, Princeton, New Jersey 08544, USA.
Malinverni
Juliana
J
Ruiz
Natividad
N
Kim
Seokhee
S
Silhavy
Thomas J
TJ
Kahne
Daniel
D
D001425:Bacterial Outer Membrane Proteins / Q000235:genetics* / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000235:genetics* / Q000378:metabolism; D006706:Homeostasis / Q000502:physiology; D008051:Lipid Bilayers / Q000378:metabolism; D008074:Lipoproteins / Q000235:genetics / Q000378:metabolism; D046912:Multiprotein Complexes / Q000235:genetics* / Q000378:metabolism; D016296:Mutagenesis; D021382:Protein Sorting Signals / Q000235:genetics
D001425:Bacterial Outer Membrane Proteins; D029968:Escherichia coli Proteins; C085044:LamB signal peptide, E coli; D008051:Lipid Bilayers; D008074:Lipoproteins; C475958:LptD protein, E coli; D046912:Multiprotein Complexes; D021382:Protein Sorting Signals; C499985:YfgL protein, E coli; C078167:OMPA outer membrane proteins