PlumX Metrics
Embed PlumX Metrics

Electrostatic couplings in OmpA ion-channel gating suggest a mechanism for pore opening

Nature Chemical Biology, ISSN: 1552-4469, Vol: 2, Issue: 11, Page: 627-635
2006
  • 109
    Citations
  • 0
    Usage
  • 95
    Captures
  • 0
    Mentions
  • 22
    Social Media
Metric Options:   Counts1 Year3 Year

Metrics Details

  • Citations
    109
  • Captures
    95
  • Social Media
    22
    • Shares, Likes & Comments
      22
      • Facebook
        22

Article Description

The molecular forces that drive structural transitions between the open and closed states of channels and transporters are not well understood. The gate of the OmpA channel is formed by the central Glu52-Arg138 salt bridge, which can open to form alternate ion pairs with Lys82 and Glu128. To gain deeper insight into the channel-opening mechanism, we measured interaction energies between the relevant side chains by double-mutant cycle analysis and correlated these with the channel activities of corresponding point mutants. The closed central salt bridge has a strong interaction energy of -5.6 kcal mol, which can be broken by forming the open-state salt bridge Glu52-Lys82 (ΔΔ G = -3.5 kcal mol) and a weak interaction between Arg138 and Glu128 (ΔΔG = -0.6 kcal mol ). A covalent disulfide bond in place of the central salt bridge completely blocks the channel. Growth assays indicate that this gating mechanism could physiologically contribute to the osmoprotection of Escherichia coli cells from environmental stress. © 2006 Nature Publishing Group.

Provide Feedback

Have ideas for a new metric? Would you like to see something else here?Let us know