Conformational dynamics of the plug domain of the SecYEG protein-conducting channel.
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.
Molecular Microbiology, Groningen Biomolecular Sciences and Biotechnology institute, and the Zernike Institute for Advanced Materials, University of Groningen, 9747 AG Groningen, The Netherlands.
Jelger A
JA
Lycklama A Nijeholt
Molecular Microbiology, Groningen Biomolecular Sciences and Biotechnology institute, and the Zernike Institute for Advanced Materials, University of Groningen, 9747 AG Groningen, The Netherlands.
Zht Cheng
ZC
Wu
Molecular Microbiology, Groningen Biomolecular Sciences and Biotechnology institute, and the Zernike Institute for Advanced Materials, University of Groningen, 9747 AG Groningen, The Netherlands. Electronic address: a.j.m.driessen@rug.nl.
Arnold J M
AJM
Driessen
D002462:Cell Membrane / Q000378:metabolism; D018360:Crystallography, X-Ray / Q000379:methods; D004926:Escherichia coli / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000378:metabolism; D005456:Fluorescent Dyes / Q000494:pharmacology; D057927:Hydrophobic and Hydrophilic Interactions; D017017:Methanococcus / Q000378:metabolism; D008958:Models, Molecular; D008968:Molecular Conformation; D010957:Plasmids / Q000378:metabolism; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D021381:Protein Transport; D012270:Ribosomes / Q000378:metabolism; D000069816:SEC Translocation Channels
D029968:Escherichia coli Proteins; D005456:Fluorescent Dyes; D000069816:SEC Translocation Channels