title: Components required for membrane assembly of newly synthesized K+ channel KcsA.
abstract: 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.
authors.affiliation: Department of Biochemistry of Membranes, Centre for Biomembranes and Lipid Enzymology, Institute of Biomembranes, Utrecht University, Utrecht, The Netherlands. a.vandalen@chem.uu.nl
authors.forename: Annemieke
authors.initials: A
authors.lastname: van Dalen
authors.forename: Martin
authors.initials: M
authors.lastname: van der Laan
authors.forename: Arnold J M
authors.initials: AJ
authors.lastname: Driessen
authors.forename: J Antoinette
authors.initials: JA
authors.lastname: Killian
authors.forename: Ben
authors.initials: B
authors.lastname: de Kruijff
mesh_terms: 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
chemical_list: 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