Ion conduction pore is conserved among potassium channels

Potassium channels, a group of specialized membrane proteins, enable K+ ion s to flow selectively across cell membranes. Transmembrane K+ currents unde rlie electrical signalling in neurons and other excitable cells. The atomic structure of a bacterial K+ channel pore has been solved by means of X-ray crystallography. To the extent that the prokaryotic pore is representative of other K+ channels, this landmark achievement has profound implications for our general understanding of K+ channels. But serious doubts have been raised concerning whether the prokaryotic K+ channel pore does actually rep resent those of eukaryotes. Here we have addressed this fundamental issue b y substituting the prokaryotic pore into eukaryotic voltage-gated and inwar d-rectifier K+ channels. The resulting chimaeras retain the respective func tional hallmarks of the eukaryotic channels, which indicates that the ion c onduction pore is indeed conserved among K+ channels.