Subunit organisation and symmetry of pore-forming, oligomeric pneumolysin

Research output: Contribution to journalArticlepeer-review


  • S C Hyman
  • A J Rowe
  • P W Andrew
  • H R Saibil

Colleges, School and Institutes


We present a detailed analysis of the oligomeric subunit organisation of pneumolysin by the use of negative stain electron microscopy and image processing to produce a projection density map. Analysis of the rotational symmetry has revealed a large and variable subunit number, between 40-50. The projected subunit density by rotational averaging shows at least two distinct subunit domains at different radial positions. Side views of the rings reveal further details concerning the dimensions of the oligomer in the membrane. On the basis of these observations and our previous knowledge of the monomer domain structure we propose that the 4-domain subunits are packed in a square planar arrangement to form the pneumolysin oligomer.


Original languageEnglish
Pages (from-to)77-80
Number of pages4
JournalFEBS Letters
Issue number1
Publication statusPublished - 28 Aug 1995


  • Bacterial Proteins, Image Processing, Computer-Assisted, Liposomes, Microscopy, Electron, Molecular Conformation, Negative Staining, Streptolysins