Crystal structures explain functional properties of two E. coli porins

Nature. 1992 Aug 27;358(6389):727-33. doi: 10.1038/358727a0.


Porins form aqueous channels that aid the diffusion of small hydrophilic molecules across the outer membrane of Gram-negative bacteria. The crystal structures of matrix porin and phosphoporin both reveal trimers of identical subunits, each subunit consisting of a 16-stranded anti-parallel beta-barrel containing a pore. A long loop inside the barrel contributes to a constriction of the channel where the charge distribution affects ion selectivity. The structures explain at the molecular level functional characteristics and their alterations by known mutations.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Bacterial Outer Membrane Proteins / ultrastructure*
  • Computer Graphics
  • Crystallography
  • Escherichia coli / ultrastructure*
  • Ion Channels / physiology
  • Ion Channels / ultrastructure*
  • Models, Molecular
  • Molecular Sequence Data
  • Mutation
  • Porins
  • Protein Conformation
  • Solubility
  • Structure-Activity Relationship
  • Water
  • X-Ray Diffraction


  • Bacterial Outer Membrane Proteins
  • Ion Channels
  • Porins
  • Water