1kn7
From Proteopedia
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| Gene: | KCNA4 (Rattus norvegicus) | ||||||
| Related: | 1zto
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| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
Solution structure of the tandem inactivation domain (residues 1-75) of potassium channel RCK4 (Kv1.4)
Overview
Cumulative inactivation of voltage-gated (Kv) K(+) channels shapes the presynaptic action potential and determines timing and strength of synaptic transmission. Kv1.4 channels exhibit rapid "ball-and-chain"-type inactivation gating. Different from all other Kvalpha subunits, Kv1.4 harbors two inactivation domains at its N terminus. Here we report the solution structure and function of this "tandem inactivation domain" using NMR spectroscopy and patch clamp recordings. Inactivation domain 1 (ID1, residues 1-38) consists of a flexible N terminus anchored at a 5-turn helix, whereas ID2 (residues 40-50) is a 2.5-turn helix made up of small hydrophobic amino acids. Functional analysis suggests that only ID1 may work as a pore-occluding ball domain, whereas ID2 most likely acts as a "docking domain" that attaches ID1 to the cytoplasmic face of the channel. Deletion of ID2 slows inactivation considerably and largely impairs cumulative inactivation. Together, the concerted action of ID1 and ID2 may promote rapid inactivation of Kv1.4 that is crucial for the channel function in short term plasticity.
About this Structure
1KN7 is a Single protein structure of sequence from Rattus norvegicus. Full crystallographic information is available from OCA.
Reference
Solution structure and function of the "tandem inactivation domain" of the neuronal A-type potassium channel Kv1.4., Wissmann R, Bildl W, Oliver D, Beyermann M, Kalbitzer HR, Bentrop D, Fakler B, J Biol Chem. 2003 May 2;278(18):16142-50. Epub 2003 Feb 16. PMID:12590144
Page seeded by OCA on Sun Mar 30 21:50:52 2008
