Twin-arginine translocase may have a role in the chaperone function of NarJ from Escherichia coli

Biochem Biophys Res Commun. 2006 Apr 28;343(1):244-51. doi: 10.1016/j.bbrc.2006.02.133. Epub 2006 Mar 3.

Abstract

NarJ is a chaperone involved in folding, maturation, and molybdenum cofactor insertion of nitrate reductase A from Escherichia coli. It has also been shown that NarJ exhibits sequence homology to a family of chaperones involved in maturation and cofactor insertion of E. coli redox enzymes that are mediated by twin-arginine translocase (Tat) dependent translocation. In this study, we show that NarJ binds the N-terminal region of NarG through Far Western studies and isothermal titration calorimetry, and the binding event occurs towards a short peptide sequence that contains a homologous twin-arginine motif. Fractionation experiments also show that the interaction of NarJ to the cytoplasmic membrane exhibits Tat-dependence. Upon further investigation through Far Western blots, the interactome of NarJ also exhibits Tat-dependence. Together the data suggest that the Tat system may play a role in the maturation pathway of nitrate reductase A.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Escherichia coli / genetics
  • Escherichia coli / metabolism*
  • Escherichia coli Proteins / chemistry
  • Escherichia coli Proteins / genetics
  • Escherichia coli Proteins / metabolism*
  • Escherichia coli Proteins / physiology*
  • Membrane Transport Proteins / genetics
  • Membrane Transport Proteins / physiology*
  • Molecular Chaperones / chemistry
  • Molecular Chaperones / metabolism*
  • Molecular Sequence Data
  • Nitrate Reductase / chemistry
  • Nitrate Reductase / metabolism*
  • Protein Conformation
  • Protein Interaction Mapping

Substances

  • Escherichia coli Proteins
  • Membrane Transport Proteins
  • Molecular Chaperones
  • NarJ protein, E coli
  • twin-arginine translocase complex, E coli
  • NarG protein, E coli
  • Nitrate Reductase