PROSITE documentation PDOC51490
KHA domain profile


Potassium channels take part in important processes of higher plants, including opening and closing of stomatal pores and leaf movement. Inward rectifying potassium (K(+)in) channels play an important role in turgor regulation and ion uptake in higher plants. All of them comprise, from their N-terminal to their C-terminal ends: a short hydrophilic region, a hydrophobic region structurally analogous and partially homologous to the transmembrane domain of voltage-gated animal channels from the Shaker superfamily, a putative cyclic nucleotide-binding domain (see <PDOC00691>), and a conserved C-terminal KHA domain. Between these last two regions, some of them (AKT1, AKT2 and SKT1) contain an ankyrin-repeat domain (see <PDOC50088>) with six repeats homologous to those of human erythrocyte ankyrin. The KHA domain is unique to plant K(+)in channels. The KHA domain contains two high-homology blocks enriched for hydrophobic and acidic residues, respectively. The KHA domain is essential for interaction of plant K(+)in channels. The KHA domain mediates tetramerization and/or stabilization of the heteromers [1,2,3].

Some proteins known to contain a KHA domain are listed below:

  • Arabidopsis thaliana AKT1.
  • Arabidopsis thaliana AKT2/3.
  • Arabidopsis thaliana KAT1.
  • Arabidopsis thaliana KAT2.
  • Potato KST1.
  • Potato SKT1.
  • Potato SKT2.
  • Potato SKT3.

The profile we developed covers the entire KHA domain.

Last update:

April 2010 / First entry.


Technical section

PROSITE method (with tools and information) covered by this documentation:

KHA, PS51490; KHA domain profile  (MATRIX)


1AuthorsEhrhardt T. Zimmermann S. Mueller-Roeber B.
TitleAssociation of plant K+(in) channels is mediated by conserved C-termini and does not affect subunit assembly.
SourceFEBS Lett. 409:166-170(1997).
PubMed ID9202139

2AuthorsDaram P. Urbach S. Gaymard F. Sentenac H. Cherel I.
TitleTetramerization of the AKT1 plant potassium channel involves its C-terminal cytoplasmic domain.
SourceEMBO J. 16:3455-3463(1997).
PubMed ID9218788

3AuthorsZimmermann S. Hartje S. Ehrhardt T. Plesch G. Mueller-Roeber B.
TitleThe K+ channel SKT1 is co-expressed with KST1 in potato guard cells--both channels can co-assemble via their conserved KT domains.
SourcePlant J. 28:517-527(2001).
PubMed ID11849592

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