1kkd

Solution structure of the calmodulin binding domain (CaMBD) of small conductance Ca2+-activated potassium channels (SK2)

spinqualitylabelsall models 1kkd, 23 NMR models Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1kkd is a 1 chain structure with sequence from Buffalo rat. Full experimental information is available from OCA. For a guided tour on the structure components use FirstGlance. Related: 1g4y Gene: SK2 (KCNN2) (Buffalo rat) Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum Function [KCNN2_RAT] Forms a voltage-independent potassium channel activated by intracellular calcium. Activation is followed by membrane hyperpolarization. Thought to regulate neuronal excitability by contributing to the slow component of synaptic afterhyperpolarization. The channel is blocked by apamin. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed Small conductance Ca(2+)-activated potassium (SK) channels underlie the afterhyperpolarization that follows the action potential in many types of central neurons. SK channels are voltage-independent and gated solely by intracellular Ca(2+) in the submicromolar range. This high affinity for Ca(2+) results from Ca(2+)-independent association of the SK alpha-subunit with calmodulin (CaM), a property unique among the large family of potassium channels. Here we report the solution structure of the calmodulin binding domain (CaMBD, residues 396-487 in rat SK2) of SK channels using NMR spectroscopy. The CaMBD exhibits a helical region between residues 423-437, whereas the rest of the molecule lacks stable overall folding. Disruption of the helical domain abolishes constitutive association of CaMBD with Ca(2+)-free CaM, and results in SK channels that are no longer gated by Ca(2+). The results show that the Ca(2+)-independent CaM-CaMBD interaction, which is crucial for channel function, is at least in part determined by a region different in sequence and structure from other CaM-interacting proteins. A helical region in the C terminus of small-conductance Ca2+-activated K+ channels controls assembly with apo-calmodulin.,Wissmann R, Bildl W, Neumann H, Rivard AF, Klocker N, Weitz D, Schulte U, Adelman JP, Bentrop D, Fakler B J Biol Chem. 2002 Feb 8;277(6):4558-64. Epub 2001 Nov 26. PMID:11723128 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Potassium Channel

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