The crystal structure of the E. coli stress protein YciF

Protein Sci. 2006 Nov;15(11):2605-11. doi: 10.1110/ps.062307706. Epub 2006 Sep 25.


YciF is a protein that is up-regulated when bacteria experience stress conditions, and is highly conserved in a range of bacterial species. YciF has no known structure or biochemical function. To learn more about its potential molecular function and its role in the bacterial stress response, we solved the crystal structure of YciF at 2.0 Angstrom resolution by the multiple wavelength anomalous diffraction (MAD) technique. YciF is a dimer in solution, and forms a homodimer in the crystal asymmetric unit. The two monomers form a dimer with a molecular twofold axis, with a significant burial of solvent-accessible surface area. The protein is an all-alpha protein composed of five helices: a four-helix bundle, and a short additional helix at the dimer interface. The protein is structurally similar to portions of the diiron-containing proteins, rubrerythrin and the Bacillus anthracis Dlp-2.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Bacillus anthracis / chemistry
  • Bacterial Proteins / chemistry
  • Binding Sites
  • Crystallography, X-Ray / methods*
  • Dimerization
  • Escherichia coli / chemistry*
  • Escherichia coli Proteins / chemistry*
  • Ferredoxins / chemistry
  • Heat-Shock Proteins / chemistry*
  • Hemerythrin
  • Ligands
  • Models, Molecular
  • Molecular Sequence Data
  • Protein Structure, Secondary
  • Rubredoxins
  • Sequence Homology, Amino Acid


  • Bacterial Proteins
  • Escherichia coli Proteins
  • Ferredoxins
  • Heat-Shock Proteins
  • Hemerythrin
  • Ligands
  • Rubredoxins
  • YciF protein, E coli
  • rubrerythrins