Twin-arginine translocase may have a role in the chaperone function of NarJ from Escherichia coli.
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.
Department of Biological Science, BI 156 Biological Sciences Bldg, University of Calgary, 2500 University Dr NW, Calgary, Alta., Canada T2N 1N4.
Catherine S
CS
Chan
Jenika M
JM
Howell
Matthew L
ML
Workentine
Raymond J
RJ
Turner
D000595:Amino Acid Sequence; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism* / Q000502:physiology*; D026901:Membrane Transport Proteins / Q000235:genetics / Q000502:physiology*; D018832:Molecular Chaperones / Q000737:chemistry / Q000378:metabolism*; D008969:Molecular Sequence Data; D050901:Nitrate Reductase / Q000737:chemistry / Q000378:metabolism*; D011487:Protein Conformation; D025941:Protein Interaction Mapping
D029968:Escherichia coli Proteins; D026901:Membrane Transport Proteins; D018832:Molecular Chaperones; C508364:NarJ protein, E coli; C408585:twin-arginine translocase complex, E coli; C508365:NarG protein, E coli; D050901:Nitrate Reductase