Membrane topology of Kch, a putative K+ channel from Escherichia coli.
We have mapped the topology of the C-terminal half of the putative potassium channel protein Kch in the inner membrane of Escherichia coli using PhoA fusions. Our results are consistent with the widely assumed six-transmembrane helix model for eukaryotic voltage-gated ion channels and place both ends of the proposed channel-lining P-segment on the periplasmic side of the inner membrane. The rather hydrophobic P-segment is found to translocate only slowly across the inner membrane and seems to be near a threshold for stop-transfer function.
Johansson
M
M
Department of Biochemistry, Stockholm University, S-106 91 Stockholm, Sweden.
von Heijne
G
G
D000595:Amino Acid Sequence; D004591:Electrophoresis, Polyacrylamide Gel; D019286:Endopeptidase K / Q000378:metabolism; D004926:Escherichia coli / Q000737:chemistry; D029968:Escherichia coli Proteins; D007700:Kinetics; D008956:Models, Chemical; D008969:Molecular Sequence Data; D015221:Potassium Channels / Q000737:chemistry* / Q000378:metabolism; D011487:Protein Conformation; D011993:Recombinant Fusion Proteins / Q000378:metabolism
D029968:Escherichia coli Proteins; D015221:Potassium Channels; D011993:Recombinant Fusion Proteins; C101871:kch protein, E coli; D019286:Endopeptidase K