Signal peptide protection by specific chaperone.
TorD is the private chaperone of TorA, a periplasmic respiratory molybdoenzyme of Escherichia coli. In this study, it is demonstrated that TorD is required to maintain the integrity of the twin-arginine signal sequence of the cytoplasmic TorA precursors. In the absence of TorD, 35 out of the 39 amino acid residues of the signal peptide were lost and the proteolysis of the N-terminal extremity of TorA precursors was not prevented by the molybdenum cofactor insertion. We thus propose that one of the main roles of TorD is to protect the TorA signal peptide to allow translocation of the enzyme by the TAT system.
Genest
Olivier
O
Laboratoire de Chimie Bactérienne, Institut de Biologie Structurale et Microbiologie, Centre National de la Recherche Scientifique Marseille, France.
Seduk
Farida
F
Ilbert
Marianne
M
Méjean
Vincent
V
Iobbi-Nivol
Chantal
C
D000595:Amino Acid Sequence; D004926:Escherichia coli / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000378:metabolism*; D026901:Membrane Transport Proteins / Q000737:chemistry* / Q000378:metabolism*; D018832:Molecular Chaperones / Q000737:chemistry* / Q000378:metabolism*; D008969:Molecular Sequence Data; D010089:Oxidoreductases, N-Demethylating / Q000737:chemistry* / Q000378:metabolism*; D021382:Protein Sorting Signals / Q000502:physiology
D029968:Escherichia coli Proteins; D026901:Membrane Transport Proteins; D018832:Molecular Chaperones; D021382:Protein Sorting Signals; C088083:TorD protein, E coli; C408585:twin-arginine translocase complex, E coli; D010089:Oxidoreductases, N-Demethylating; C023186:trimethylamine dehydrogenase