X-ray structure of a voltage-dependent K+ channel.
Voltage-dependent K+ channels are members of the family of voltage-dependent cation (K+, Na+ and Ca2+) channels that open and allow ion conduction in response to changes in cell membrane voltage. This form of gating underlies the generation of nerve and muscle action potentials, among other processes. Here we present the structure of KvAP, a voltage-dependent K+ channel from Aeropyrum pernix. We have determined a crystal structure of the full-length channel at a resolution of 3.2 A, and of the isolated voltage-sensor domain at 1.9 A, both in complex with monoclonal Fab fragments. The channel contains a central ion-conduction pore surrounded by voltage sensors, which form what we call 'voltage-sensor paddles'-hydrophobic, cationic, helix-turn-helix structures on the channel's outer perimeter. Flexible hinges suggest that the voltage-sensor paddles move in response to membrane voltage changes, carrying their positive charge across the membrane.
Jiang
Youxing
Y
Howard Hughes Medical Institute, Laboratory of Molecular Neurobiology and Biophysics, Laboratory of Mass Spectrometry and Gaseous Ion Chemistry, Rockefeller University, 1230 York Avenue, New York, New York 10021, USA.
Lee
Alice
A
Chen
Jiayun
J
Ruta
Vanessa
V
Cadene
Martine
M
Chait
Brian T
BT
MacKinnon
Roderick
R
D000595:Amino Acid Sequence; D000911:Antibodies, Monoclonal / Q000737:chemistry / Q000276:immunology; D019843:Archaeal Proteins / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000276:immunology / Q000378:metabolism; D018360:Crystallography, X-Ray; D019620:Desulfurococcaceae / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D007140:Immunoglobulin Fab Fragments / Q000737:chemistry / Q000276:immunology; D015640:Ion Channel Gating; D008958:Models, Molecular; D008969:Molecular Sequence Data; D024642:Potassium Channels, Voltage-Gated / Q000737:chemistry* / Q000276:immunology / Q000378:metabolism; D017434:Protein Structure, Tertiary; D055672:Static Electricity
D000911:Antibodies, Monoclonal; D019843:Archaeal Proteins; D007140:Immunoglobulin Fab Fragments; D024642:Potassium Channels, Voltage-Gated