1KKD
Solution structure of the calmodulin binding domain (CaMBD) of small conductance Ca2+-activated potassium channels (SK2)
Summary for 1KKD
| Entry DOI | 10.2210/pdb1kkd/pdb |
| Related | 1G4Y |
| Descriptor | Small conductance calcium-activated potassium channel protein 2 (1 entity in total) |
| Functional Keywords | small-conductance calcium-activated potassium channel, calmodulin binding domain (cambd), channel gating, signaling protein |
| Biological source | Rattus norvegicus (Norway rat) |
| Cellular location | Membrane; Multi-pass membrane protein: P70604 |
| Total number of polymer chains | 1 |
| Total formula weight | 12243.40 |
| Authors | Wissmann, R.,Bildl, W.,Neumann, H.,Rivard, A.F.,Kloecker, N.,Weitz, D.,Schulte, U.,Adelman, J.P.,Bentrop, D.,Fakler, B. (deposition date: 2001-12-07, release date: 2001-12-14, Last modification date: 2024-05-22) |
| Primary citation | Wissmann, R.,Bildl, W.,Neumann, H.,Rivard, A.F.,Klocker, N.,Weitz, D.,Schulte, U.,Adelman, J.P.,Bentrop, D.,Fakler, B. A helical region in the C terminus of small-conductance Ca2+-activated K+ channels controls assembly with apo-calmodulin. J.Biol.Chem., 277:4558-4564, 2002 Cited by PubMed Abstract: 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. PubMed: 11723128DOI: 10.1074/jbc.M109240200 PDB entries with the same primary citation |
| Experimental method | SOLUTION NMR |
Structure validation
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