Components required for membrane assembly of newly synthesized K+ channel KcsA.
An Escherichia coli in vitro transcription-translation system was used to study the components involved in the biogenesis of the homotetrameric potassium channel KcsA. We show that a functional signal recognition particle pathway is essential for tetramer formation, probably to direct correct monomer insertion in the membrane. In the absence of YidC or at reduced SecYEG levels, KcsA assembly occurs with lower efficiency. Strikingly, the highest efficiency of tetramerization was observed when transcription-translation was carried out in the presence of pure lipid vesicles, demonstrating that a phospholipid bilayer is the minimal membrane requirement to form the KcsA tetramer. It is concluded that SecYEG and YidC are not required for the formation of tetrameric KcsA in vitro.
van Dalen
Annemieke
A
Department of Biochemistry of Membranes, Centre for Biomembranes and Lipid Enzymology, Institute of Biomembranes, Utrecht University, Utrecht, The Netherlands. a.vandalen@chem.uu.nl
van der Laan
Martin
M
Driessen
Arnold J M
AJ
Killian
J Antoinette
JA
de Kruijff
Ben
B
D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism; D017353:Gene Deletion; D008051:Lipid Bilayers / Q000737:chemistry / Q000378:metabolism; D008081:Liposomes / Q000737:chemistry / Q000378:metabolism; D008565:Membrane Proteins / Q000096:biosynthesis / Q000737:chemistry* / Q000378:metabolism*; D026901:Membrane Transport Proteins; D015221:Potassium Channels / Q000096:biosynthesis / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D014176:Protein Biosynthesis; D011499:Protein Processing, Post-Translational; D020836:Protein Structure, Quaternary; D021122:Protein Subunits; D011510:Proteolipids / Q000737:chemistry / Q000378:metabolism; D015398:Signal Transduction; D014158:Transcription, Genetic
D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D008051:Lipid Bilayers; D008081:Liposomes; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D015221:Potassium Channels; D021122:Protein Subunits; D011510:Proteolipids; C412443:YIDC protein, E coli; C107790:prokaryotic potassium channel; C020485:proteoliposomes