10th International Frumkin Symposium on Electrochemistry
Sprache des Tagungstitel:
Voltage sensitivity of SecYEG
D. Knyazev, C. Siligan, R. Kuttner, P. Pohl.
The bacterial translocation channel Se?YEG opens upon binding of ligands such as (i) ribosome , (ii) SecA, or (iii) signal peptides. These ion conductive channels close at physiological transmembrane potentials , thereby preventing the dissipation of the proton electrochemical potential. To identify the voltage sensor, we reconstituted the purified SecYEG complex into planar bilayers. Helix immobilization by artificial disulfide bridges as well as the mutational analysis of putative gating charges allowed the identification of voltage insensitive SecYEG variants. However, docking of a stalled ribosome-nascent chain complex restored voltage sensitivity to some degree. Experiments are under way to identify its origin.
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