Assessing the conformational changes of pb5, the receptor-binding protein of phage T5, upon binding to its Escherichia coli receptor FhuA

J Biol Chem. 2013 Oct 18;288(42):30763-30772. doi: 10.1074/jbc.M113.501536. Epub 2013 Sep 6.


Within tailed bacteriophages, interaction of the receptor-binding protein (RBP) with the target cell triggers viral DNA ejection into the host cytoplasm. In the case of phage T5, the RBP pb5 and the receptor FhuA, an outer membrane protein of Escherichia coli, have been identified. Here, we use small angle neutron scattering and electron microscopy to investigate the FhuA-pb5 complex. Specific deuteration of one of the partners allows the complete masking in small angle neutron scattering of the surfactant and unlabeled proteins when the complex is solubilized in the fluorinated surfactant F6-DigluM. Thus, individual structures within a membrane protein complex can be described. The solution structure of FhuA agrees with its crystal structure; that of pb5 shows an elongated shape. Neither displays significant conformational changes upon interaction. The mechanism of signal transduction within phage T5 thus appears different from that of phages binding cell wall saccharides, for which structural information is available.

Keywords: Bacteriophage; Biophysics; Electron Microscopy (EM); Fluorinated Surfactant; Membrane Proteins; Small Angle Neutron Scattering; Viral Protein.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Outer Membrane Proteins / chemistry*
  • Bacterial Outer Membrane Proteins / metabolism
  • Escherichia coli / chemistry*
  • Escherichia coli / metabolism
  • Escherichia coli / virology
  • Escherichia coli Proteins / chemistry*
  • Escherichia coli Proteins / metabolism
  • Multiprotein Complexes / chemistry*
  • Multiprotein Complexes / metabolism
  • Neutron Diffraction
  • Protein Structure, Quaternary
  • Protein Structure, Tertiary
  • Scattering, Small Angle
  • Siphoviridae / chemistry*
  • Siphoviridae / metabolism
  • Surface-Active Agents
  • Viral Structural Proteins / chemistry*
  • Viral Structural Proteins / metabolism


  • Bacterial Outer Membrane Proteins
  • Escherichia coli Proteins
  • FhuA protein, E coli
  • Multiprotein Complexes
  • Surface-Active Agents
  • Viral Structural Proteins