Crystal structure of the PAS domain of the hEAG potassium channel

Acta Crystallogr F Struct Biol Commun. 2016 Aug;72(Pt 8):578-85. doi: 10.1107/S2053230X16009419. Epub 2016 Jul 13.


KCNH voltage-gated potassium channels play critical roles in regulating cellular functions. The channel is composed of four subunits, each of which contains six transmembrane helices forming the central pore. The cytoplasmic parts of the subunits present a Per-Arnt-Sim (PAS) domain at the N-terminus and a cyclic nucleotide-binding homology domain at the C-terminus. PAS domains are conserved from prokaryotes to eukaryotes and are involved in sensing signals and cellular responses. To better understand the functional roles of PAS domains in KCNH channels, the structure of this domain from the human ether-à-go-go channel (hEAG channel) was determined. By comparing it with the structures of the Homo sapiens EAG-related gene (hERG) channel and the Drosophila EAG-like K(+) (dELK) channel and analyzing the structural features of the hEAG channel, it was identified that a hydrophobic patch on the β-sheet may mediate interaction between the PAS domain and other regions of the channel to regulate its functions.

Keywords: KCNH channels; PAS domain; ether-à-go-go channel; hEAG potassium chanels.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Binding Sites
  • Cloning, Molecular
  • Crystallography, X-Ray
  • Drosophila Proteins / chemistry*
  • Drosophila Proteins / genetics
  • Drosophila Proteins / metabolism
  • Drosophila melanogaster / chemistry
  • Drosophila melanogaster / metabolism
  • ERG1 Potassium Channel / chemistry*
  • ERG1 Potassium Channel / genetics
  • ERG1 Potassium Channel / metabolism
  • Escherichia coli / genetics
  • Escherichia coli / metabolism
  • Ether-A-Go-Go Potassium Channels / chemistry*
  • Ether-A-Go-Go Potassium Channels / genetics
  • Ether-A-Go-Go Potassium Channels / metabolism
  • Gene Expression
  • Humans
  • Hydrophobic and Hydrophilic Interactions
  • Models, Molecular
  • Plasmids / chemistry*
  • Plasmids / metabolism
  • Potassium Channels / chemistry*
  • Potassium Channels / genetics
  • Potassium Channels / metabolism
  • Protein Binding
  • Protein Conformation, alpha-Helical
  • Protein Conformation, beta-Strand
  • Protein Interaction Domains and Motifs
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism
  • Sequence Alignment
  • Structural Homology, Protein


  • Drosophila Proteins
  • ERG1 Potassium Channel
  • Elk protein, Drosophila
  • Ether-A-Go-Go Potassium Channels
  • KCNH1 protein, human
  • KCNH2 protein, human
  • Potassium Channels
  • Recombinant Proteins