A Periplasmic Protein (Skp) of Escherichia Coli Selectively Binds a Class of Outer Membrane Proteins

Mol Microbiol. 1996 Mar;19(6):1287-94. doi: 10.1111/j.1365-2958.1996.tb02473.x.


A search was performed for a periplasmic molecular chaperone which may assist outer membrane proteins of Escherichia coli on their way from the cytoplasmic to the outer membrane. Proteins of the periplasmic space were fractionated on an affinity column with sepharose-bound outer membrane porin OmpF. A 17 kDa polypeptide was the predominant protein retained by this column. The corresponding gene was found in a gene bank; it encodes the periplasmic protein Skp. The protein was isolated and it could be demonstrated that it bound outer membrane proteins, following SDS-PAGE, with high selectivity. Among these were OmpA, OmpC, OmpF and the maltoporin LamB. The chromosomal skp gene was inactivated by a deletion causing removal of most of the signal peptide plus 107 residues of the 141-residue mature protein. The mutant was viable but possessed much-reduced concentrations of outer membrane proteins. This defect was fully restored by a plasmid-borne skp gene which may serve as a periplasmic chaperone.

MeSH terms

  • Bacterial Outer Membrane Proteins / metabolism*
  • Bacterial Proteins / genetics
  • Bacterial Proteins / isolation & purification
  • Bacterial Proteins / metabolism*
  • Base Sequence
  • DNA, Bacterial / genetics
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / isolation & purification
  • DNA-Binding Proteins / metabolism*
  • Escherichia coli / genetics
  • Escherichia coli / metabolism*
  • Escherichia coli Proteins*
  • Gene Deletion
  • Genes, Bacterial
  • Molecular Chaperones / genetics
  • Molecular Chaperones / isolation & purification
  • Molecular Chaperones / metabolism
  • Protein Binding


  • Bacterial Outer Membrane Proteins
  • Bacterial Proteins
  • DNA, Bacterial
  • DNA-Binding Proteins
  • Escherichia coli Proteins
  • Molecular Chaperones
  • Skp protein, E coli