Abstract
The overall sequence similarity between the voltage-activated K + channels and cyclic nucleotide-gated ion channels from retinal and olfactory neurons suggests that they arose from a common ancestor. On the basis of sequence comparisons, mutations were introduced into the pore of a voltage-activated K + channel. These mutations confer the essential features of ion conduction in the cyclic nucleotide-gated ion channels; the mutant K + channels display little selectivity among monovalent cations and are blocked by divalent cations. The property of K + selectivity is related to the presence of two amino acids that are absent from the pore-forming region of the cyclic nucleotide-gated channels. These data demonstrate that very small differences in the primary structure of an ion channel can account for extreme functional diversity, and they suggest a possible connection between the pore-forming regions of K + , Ca 2+ , and cyclic nucleotide-gated ion channels.
Keywords
Ion channelCyclic nucleotide-gated ion channelDivalentNucleotideBiophysicsChemistryIonMutantSelectivityIon transporterCyclic nucleotideCrystallographyBiologyBiochemistryGene
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Publication Info
- Year
- 1992
- Type
- article
- Volume
- 258
- Issue
- 5085
- Pages
- 1152-1155
- Citations
- 484
- Access
- Closed
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Cite This
Lise Heginbotham,
Tatiana Abramson,
Roderick MacKinnon
(1992).
A Functional Connection Between the Pores of Distantly Related Ion Channels as Revealed by Mutant K <sup>+</sup> Channels.
Science
, 258
(5085)
, 1152-1155.
https://doi.org/10.1126/science.1279807
Identifiers
- DOI
- 10.1126/science.1279807