title: The MlotiK1 channel transports ions along the canonical conduction pore.
abstract: Although the cyclic nucleotide-modulated potassium channel from Mesorhizobium loti, MlotiK1, is easily studied using a 86Rb+ flux assay, its comparatively low activity raises serious concerns about the integrity of the purified protein. We investigated the pathway of uptake using a multi-pronged approach. First, we probed the conduction pathway using quaternary ammonium compounds known to block conduction in eukaryotic K+ channels. Second, we examined the effect of chemical modification of putative pore-lining residues. Our results are consistent with ions traversing MlotiK1 along a conduction pathway like that of the eukaryotic channels, but at a much slower rate.
authors.affiliation: Department of Molecular, Biophysics and Biochemistry, Yale University, 260 Whitney Avenue, P.O. Box 208114, New Haven, CT 06520-8114, USA.
authors.forename: William R
authors.initials: WR
authors.lastname: Silverman
authors.forename: Lise
authors.initials: L
authors.lastname: Heginbotham
mesh_terms: D020561:Alphaproteobacteria / Q000378:metabolism*; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000502:physiology*; D017136:Ion Transport; D008969:Molecular Sequence Data; D010539:Permeability; D026902:Potassium Channel Blockers / Q000494:pharmacology; D015221:Potassium Channels / Q000737:chemistry / Q000187:drug effects / Q000502:physiology*; D011487:Protein Conformation; D000644:Quaternary Ammonium Compounds / Q000494:pharmacology
chemical_list: D001426:Bacterial Proteins; D026902:Potassium Channel Blockers; D015221:Potassium Channels; D000644:Quaternary Ammonium Compounds