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Components required for membrane assembly of newly synthesized K + channel KcsA
Author(s) -
van Dalen Annemieke,
van der Laan Martin,
Driessen Arnold J.M.,
Killian J.Antoinette,
de Kruijff Ben
Publication year - 2002
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(01)03278-1
Subject(s) - kcsa potassium channel , tetramer , biophysics , chemistry , bilayer , lipid bilayer , nanodisc , membrane , membrane protein , biochemistry , crystallography , ion channel , biology , receptor , enzyme
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.