1. Conformational dynamics of the plug domain of the SecYEG protein-conducting channel.
- Author
-
Lycklama A Nijeholt JA, Wu ZC, and Driessen AJM
- Subjects
- Cell Membrane metabolism, Crystallography, X-Ray methods, Escherichia coli Proteins metabolism, Fluorescent Dyes pharmacology, Hydrophobic and Hydrophilic Interactions, Methanococcus metabolism, Models, Molecular, Molecular Conformation, Plasmids metabolism, Protein Conformation, Protein Structure, Secondary, Protein Structure, Tertiary, Protein Transport, Ribosomes metabolism, SEC Translocation Channels, Escherichia coli metabolism, Escherichia coli Proteins chemistry
- Abstract
The central pore of the SecYEG preprotein-conducting channel is closed at the periplasmic face of the membrane by a plug domain. To study its conformational dynamics, the plug was labeled site-specifically with an environment-sensitive fluorophore. In the presence of a stable preprotein translocation inter-mediate, the SecY plug showed an enhanced solvent exposure consistent with a displacement from the hydrophobic central pore region. In contrast, binding and insertion of a ribosome-bound nascent membrane protein did not alter the plug conformation. These data indicate different plug dynamics depending on the ligand bound state of the SecYEG channel.
- Published
- 2011
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