TonB protein of Salmonella typhimurium. A model for signal transduction between membranes.

摘要: The tonB gene product is required for several outer membrane transport processes in bacteria. from Salmonella typhimurium was sequenced and found to be similar that of Escherichia coli. TonB protein highly proline-rich includes an unusual segment consisting multiple X-Pro dipeptide repeats. A synthetic peptide corresponding this has been used raise anti-TonB antibodies. shown associated with the cytoplasmic membrane, apparently anchored via a single hydrophobic N-terminal segment. Protease accessibility studies, use series TonB-beta-lactamase fusions, showed rest periplasmic. Unusually, export not accompanied by cleavage signal peptide. In accompanying paper, we show interacts directly FhuA (TonA) receptor. Thus, must span periplasm, providing link between receptors membrane. On basis these data, those published other laboratories, propose model whereby serves as "mechanical" linkage that, transmitting conformational changes across acts means coupling energy processes. Such mechanism general implications transduction within proteins.