Genetic selection designed to stabilize proteins uncovers a chaperone called Spy

Nat Struct Mol Biol. 2011 Mar;18(3):262-9. doi: 10.1038/nsmb.2016. Epub 2011 Feb 13.

Abstract

To optimize the in vivo folding of proteins, we linked protein stability to antibiotic resistance, thereby forcing bacteria to effectively fold and stabilize proteins. When we challenged Escherichia coli to stabilize a very unstable periplasmic protein, it massively overproduced a periplasmic protein called Spy, which increases the steady-state levels of a set of unstable protein mutants up to 700-fold. In vitro studies demonstrate that the Spy protein is an effective ATP-independent chaperone that suppresses protein aggregation and aids protein refolding. Our strategy opens up new routes for chaperone discovery and the custom tailoring of the in vivo folding environment. Spy forms thin, apparently flexible cradle-shaped dimers. The structure of Spy is unlike that of any previously solved chaperone, making it the prototypical member of a new class of small chaperones that facilitate protein refolding in the absence of energy cofactors.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Crystallography, X-Ray
  • Escherichia coli / chemistry
  • Escherichia coli / genetics*
  • Escherichia coli / metabolism*
  • Escherichia coli Proteins / chemistry
  • Escherichia coli Proteins / genetics
  • Escherichia coli Proteins / metabolism*
  • Models, Molecular
  • Molecular Chaperones / genetics
  • Molecular Chaperones / metabolism*
  • Periplasmic Proteins / chemistry
  • Periplasmic Proteins / genetics
  • Periplasmic Proteins / metabolism*
  • Protein Engineering*
  • Protein Folding
  • Protein Multimerization
  • Protein Stability
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • Tannins / metabolism
  • Up-Regulation

Substances

  • Escherichia coli Proteins
  • Molecular Chaperones
  • Periplasmic Proteins
  • Recombinant Fusion Proteins
  • Spy protein, E coli
  • Tannins