The periplasmic E. coli chaperone Skp is a trimer in solution: biophysical and preliminary crystallographic characterization

Biol Chem. 2004 Feb;385(2):137-43. doi: 10.1515/BC.2004.032.

Abstract

The 'seventeen kilodalton protein' Skp confers transient solubility on outer membrane proteins during biogenesis in Gram-negative bacteria. Here we report a first biophysical characterization of this chaperone itself, which also possesses biotechnological potential in the production of recombinant proteins. Using cross-linking and gel filtration methods, we found that Skp forms a stable homo-trimer in solution. Following thermal denaturation, monitored by CD spectroscopy, this chaperone refolds with high efficiency but exhibits a pronounced hysteresis between the un- and refolding transitions. Using the recombinant protein equipped with the Strep-tag II at its N-terminus, suitable crystallization conditions for Skp were found. A first data set was collected to 2.60 A resolution.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Circular Dichroism
  • Crystallization
  • Crystallography, X-Ray
  • DNA-Binding Proteins / chemistry*
  • DNA-Binding Proteins / genetics
  • Escherichia coli / metabolism
  • Escherichia coli Proteins / chemistry*
  • Escherichia coli Proteins / genetics
  • Hot Temperature
  • Molecular Chaperones / chemistry*
  • Molecular Chaperones / genetics
  • Molecular Sequence Data
  • Periplasm / metabolism
  • Periplasmic Proteins / chemistry*
  • Periplasmic Proteins / genetics
  • Protein Denaturation
  • Protein Renaturation
  • Protein Structure, Quaternary
  • Protein Structure, Secondary
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / genetics

Substances

  • DNA-Binding Proteins
  • Escherichia coli Proteins
  • Molecular Chaperones
  • Periplasmic Proteins
  • Recombinant Proteins
  • Skp protein, E coli