Three-dimensional model of purple membrane obtained by electron microscopy

Nature. 1975 Sep 4;257(5521):28-32. doi: 10.1038/257028a0.


A 7-A resolution map of the purple membrane has been obtained by electron microscopy of tilted, unstained specimens. The protein in the membrane contains seven, closely packed, alpha-helical segments which extend roughly perpendicular to the plane of the membrane for most of its width. Lipid bilayer regions fill the spaces between the protein molecules.

MeSH terms

  • Bacterial Proteins
  • Bacteriorhodopsins*
  • Carotenoids*
  • Halobacterium / ultrastructure*
  • Lipids
  • Microscopy, Electron / methods
  • Models, Structural
  • Protein Conformation


  • Bacterial Proteins
  • Lipids
  • Carotenoids
  • Bacteriorhodopsins