Coat protein fold and maturation transition of bacteriophage P22 seen at subnanometer resolutions

Nat Struct Biol. 2003 Feb;10(2):131-5. doi: 10.1038/nsb891.


Bacteriophage P22 is a prototypical biological machine used for studying protein complex assembly and capsid maturation. Using cryo-EM, we solved the structures of P22 before and after the capsid maturation at 8.5 A and 9.5 A resolutions, respectively. These structures allowed visualization of alpha-helices and beta-sheets from which the capsid protein fold is derived. The capsid fold is similar to that of the coat protein of HK97 bacteriophage. The cryo-EM shows that a large conformational change of the P22 capsid during maturation transition involves not only the domain movement of individual subunits, but also refolding of the capsid protein.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Bacteriophage P22 / chemistry*
  • Bacteriophage P22 / growth & development
  • Bacteriophage P22 / ultrastructure*
  • Capsid Proteins / chemistry*
  • Capsid Proteins / ultrastructure*
  • Cryoelectron Microscopy
  • Models, Molecular
  • Protein Conformation
  • Protein Folding
  • Protein Structure, Secondary
  • Protein Subunits


  • Capsid Proteins
  • Protein Subunits