SecYEG proteoliposomes catalyze the Deltaphi-dependent membrane insertion of FtsQ.
In Escherichia coli, the insertion of most inner membrane proteins is mediated by the Sec translocase. Ribosome-bound nascent chains of Sec-dependent inner membrane proteins are targeted to the SecYEG complex via the signal recognition particle pathway. We now demonstrate that the signal recognition particle-dependent co-translational membrane targeting and membrane insertion of FtsQ can be reconstituted with proteoliposomes containing purified SecYEG. SecA and a transmembrane electrical potential are essential for the translocation of the large periplasmic domain of FtsQ, whereas co-reconstituted YidC has an inhibitory effect. These data demonstrate that membrane protein insertion can be reconstituted with a minimal set of purified Sec components.
Department of Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Kerklaan 30, 9751 NN Haren, The Netherlands.
Martin
M
van der Laan
Nico
N
Nouwen
Arnold J M
AJ
Driessen
D000251:Adenosine Triphosphatases / Q000378:metabolism; D001426:Bacterial Proteins / Q000378:metabolism; D002384:Catalysis; D029968:Escherichia coli Proteins / Q000378:metabolism* / Q000502:physiology*; D008565:Membrane Proteins / Q000378:metabolism*; D026901:Membrane Transport Proteins / Q000378:metabolism / Q000502:physiology; D011510:Proteolipids / Q000502:physiology*; D018892:Proton-Motive Force; D000069816:SEC Translocation Channels; D000081416:SecA Proteins
D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; C068023:FtsQ protein, E coli; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D011510:Proteolipids; D000069816:SEC Translocation Channels; C057841:SecY protein, E coli; C412443:YIDC protein, E coli; C020485:proteoliposomes; D000251:Adenosine Triphosphatases; D000081416:SecA Proteins