@article{89671,
  keywords = {Models, Molecular, Protein Conformation, Temperature, Protein Structure, Tertiary, Escherichia coli, Molecular Sequence Data, Amino Acid Sequence, Escherichia coli Proteins, Sequence Alignment, Multiprotein Complexes, Sequence Homology, Amino Acid, Conserved Sequence, Protein Interaction Mapping, Lipid Bilayers, Bacterial Outer Membrane Proteins, Mutation, Missense, Suppression, Genetic, Point Mutation, Codon, Lipid-Linked Proteins},
  author = {Dante Ricci and Christine Hagan and Daniel Kahne and Thomas Silhavy},
  title = {Activation of the Escherichia coli β-barrel assembly machine (Bam) is required for essential components to interact properly with substrate},
  abstract = {<p>The outer membrane (OM) of gram-negative bacteria such as Escherichia coli contains lipoproteins and integral β-barrel proteins (outer-membrane proteins, OMPs) assembled into an asymmetrical lipid bilayer. Insertion of β-barrel proteins into the OM is mediated by a protein complex that contains the OMP BamA and four associated lipoproteins (BamBCDE). The mechanism by which the Bam complex catalyzes the assembly of OMPs is not known. We report here the isolation and characterization of a temperature-sensitive lethal mutation, bamAE373K, which alters the fifth polypeptide transport-associated domain and disrupts the interaction between the BamAB and BamCDE subcomplexes. Suppressor mutations that map to codon 197 in bamD restore Bam complex function to wild-type levels. However, these suppressors do not restore the interaction between BamA and BamD; rather, they bypass the requirement for stable holocomplex formation by activating BamD. These results imply that BamA and BamD interact directly with OMP substrates.</p>
},
  year = {2012},
  journal = {Proc Natl Acad Sci U S A},
  volume = {109},
  pages = {3487-91},
  month = {02/2012},
  issn = {1091-6490},
  doi = {10.1073/pnas.1201362109},
  language = {eng},
}