A sequence-specific function for the N-terminal signal-like sequence of the TonB protein.
TonB is a proline-rich protein which provides a functional link between the inner and outer membranes of Gram-negative bacteria. TonB is anchored to the inner membrane via an N-terminal signal-like sequence and spans the periplasm, interacting with transport receptors in the outer membrane. We have investigated the role of the N-terminal signal-like peptide in TonB function. Replacement of the N-terminal sequence with heterologous sequences indicates that it has at least three distinct roles in TonB function: (i) to facilitate translocation of TonB across the cytoplasmic membrane; (ii) to anchor TonB to the cytoplasmic membrane; (iii) a sequence-specific functional interaction with the ExbBD proteins.
Karlsson
M
M
Imperial Cancer Research Fund Laboratories, University of Oxford, John Radcliffe Hospital, UK.
Hannavy
K
K
Higgins
C F
CF
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism*; D001692:Biological Transport; D016384:Consensus Sequence; D004926:Escherichia coli / Q000378:metabolism*; D029968:Escherichia coli Proteins; D006090:Gram-Negative Bacteria / Q000378:metabolism; D008565:Membrane Proteins / Q000737:chemistry / Q000378:metabolism*; D008969:Molecular Sequence Data; D021382:Protein Sorting Signals / Q000737:chemistry; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; C052874:ExbB protein, E coli; D008565:Membrane Proteins; D021382:Protein Sorting Signals; C062093:tolA protein, E coli; C057616:tonB protein, Bacteria; C489181:tonB protein, E coli; C060792:tolQ protein, E coli; C060790:exbD protein, E coli