10th International Frumkin Symposium on Electrochemistry
Sprache des Tagungstitel:
Englisch
Original Kurzfassung:
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 [1], (ii) SecA, or (iii) signal peptides. These ion conductive channels close at physiological transmembrane potentials [2], 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.
Reference List
1. Knyazev DG, Lents A, Krause E, Ollinger N, Siligan C, Papinski D, Winter L, Horner A, Pohl P (2013) The Bacterial Translocon SecYEG Opens upon Ribosome Binding. J Biol Chem 288:17941-17946.
2. Knyazev DG, Winter L, Bauer BW, Siligan C, Pohl P (2014) Ion Conductivity of the Bacterial Translocation Channel SecYEG Engaged in Translocation. J Biol Chem 289:24611-24616.
3. Sapar M. Saparov, Karl Erlandson, Kurt Cannon, Julia Schaletzky, Sol Schulman, Tom A. Rapoport, and Peter Pohl (2007). Determining the Conductance of the SecY Protein Translocation Channel for Small Molecules. Mol. Cell 26: 501-509.
Forschungs-