A Gating Charge Transfer Center in Voltage Sensors

• DOI: 10.1126/science.1185954
• Publication Date: 2010-04-01T20:36:02Z
• Authors: Xiao Tao; Alice Lee; Walrati Limapichat; Dennis A. Dougherty; Roderick MacKinnon
• Keywords: Models, Molecular; 0301 basic medicine; 570; Binding Sites; Patch-Clamp Techniques; Protein Conformation; Lysine; Phenylalanine; Recombinant Fusion Proteins; Molecular Sequence Data; Tryptophan; Arginine; Crystallography, X-Ray; Electric Capacitance; Rats; 03 medical and health sciences; Shab Potassium Channels; Amino Acid Substitution; Kv1.2 Potassium Channel; Shaker Superfamily of Potassium Channels; Animals; Amino Acid Sequence; Ion Channel Gating

Voltage sensors regulate the conformations of voltage-dependent ion channels and enzymes. Their nearly switchlike response as a function membrane voltage comes from movement positively charged amino acids, arginine or lysine, across field. We used mutations with natural unnatural electrophysiological recordings, x-ray crystallography to identify charge transfer center in that facilitates this movement. This consists rigid cyclic "cap" two negatively acids interact positive charge. Specific induce preference for lysine relative arginine. By placing at specific locations, sensor can be stabilized different conformations, which enables dissection movements their relation channel opening.