Structure of a conserved Golgi complex-targeting signal in coronavirus envelope proteins

J Biol Chem. 2014 May 2;289(18):12535-49. doi: 10.1074/jbc.M114.560094. Epub 2014 Mar 25.

Abstract

Coronavirus envelope (CoV E) proteins are ∼100-residue polypeptides with at least one channel-forming α-helical transmembrane (TM) domain. The extramembrane C-terminal tail contains a completely conserved proline, at the center of a predicted β-coil-β motif. This hydrophobic motif has been reported to constitute a Golgi-targeting signal or a second TM domain. However, no structural data for this or other extramembrane domains in CoV E proteins is available. Herein, we show that the E protein in the severe acute respiratory syndrome virus has only one TM domain in micelles, whereas the predicted β-coil-β motif forms a short membrane-bound α-helix connected by a disordered loop to the TM domain. However, complementary results suggest that this motif is potentially poised for conformational change or in dynamic exchange with other conformations.

Keywords: Analytical Ultracentrifugation; Coronavirus; Envelope Protein; Golgi Targeting; Nuclear Magnetic Resonance (NMR); Protein Structure; SARS; Structural Biology; Viral Protein; Virus Assembly.

MeSH terms

  • Amino Acid Sequence
  • Binding Sites / genetics
  • Circular Dichroism
  • Electrophoresis, Polyacrylamide Gel
  • Escherichia coli / genetics
  • Golgi Apparatus / metabolism*
  • Humans
  • Models, Molecular
  • Molecular Sequence Data
  • Mutation
  • Protein Multimerization
  • Protein Structure, Secondary
  • Protein Structure, Tertiary
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / metabolism
  • SARS Virus / genetics
  • SARS Virus / metabolism*
  • Sequence Homology, Amino Acid
  • Signal Transduction*
  • Spectroscopy, Fourier Transform Infrared
  • Viral Envelope Proteins / chemistry
  • Viral Envelope Proteins / genetics
  • Viral Envelope Proteins / metabolism*
  • Viroporin Proteins

Substances

  • E protein, SARS coronavirus
  • Recombinant Proteins
  • Viral Envelope Proteins
  • Viroporin Proteins

Associated data

  • PDB/2MM4