Monitoring the Activity of Single TransloconsTaufik, I., Kedrov, A., Exterkate, M. & Driessen, A. J. M., 15-Nov-2013, In : Journal of Molecular Biology. 425, 22, p. 4145-4153 9 p.
Research output: Contribution to journal › Article › Academic › peer-review
Recent studies introduced a novel view that the SecYEG translocon functions as a monomer and interacts with the dimeric SecA ATPase, which fuels the preprotein translocation reaction. Here, we used nanodisc-reconstituted SecYEG to characterize the functional properties of single copies of the translocon. Using a method based on intermolecular Forster resonance energy transfer, we show for the first time that isolated nanodisc-reconstituted SecYEG monomers support preprotein translocation. When several copies of SecYEG were co-reconstituted within a nanodisc, no change in translocation kinetics was observed, suggesting that SecYEG oligomers do not facilitate enhanced translocation. In contrast, nanodisc-reconstituted monomers of the PrIA4 variant of SecYEG showed increased translocation rates. Experiments based on intramolecular Forster resonance energy transfer within the nanodisc-isolated monomeric SecYEG demonstrated a nucleotide-dependent opening of the channel upon interaction with SecA. In conclusion, the nanodisc-reconstituted SecYEG monomers are functional for preprotein translocation and provide a new prospect for single-molecule analysis of dynamic aspects of protein translocation. (C) 2013 Elsevier Ltd. All rights reserved.
|Number of pages||9|
|Journal||Journal of Molecular Biology|
|Publication status||Published - 15-Nov-2013|
- protein transport, secretion, protein oligomerization, protein dynamics, membrane proteins, BACTERIAL CYTOPLASMIC MEMBRANE, PHOSPHOLIPID-BILAYER NANODISCS, PROTEIN-TRANSLOCATION, ESCHERICHIA-COLI, SIGNAL SEQUENCE, PREPROTEIN TRANSLOCATION, PRECURSOR PROTEINS, SECY COMPLEX, CHANNEL, ATPASE