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| | ==Solution structure of the cytoplasmic N-terminus of the BK beta-subunit KCNMB2== | | ==Solution structure of the cytoplasmic N-terminus of the BK beta-subunit KCNMB2== |
| - | <StructureSection load='1jo6' size='340' side='right' caption='[[1jo6]], [[NMR_Ensembles_of_Models | 24 NMR models]]' scene=''> | + | <StructureSection load='1jo6' size='340' side='right'caption='[[1jo6]]' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[1jo6]] is a 1 chain structure. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1JO6 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1JO6 FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[1jo6]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1JO6 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1JO6 FirstGlance]. <br> |
| - | </td></tr><tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1jo6 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1jo6 OCA], [http://pdbe.org/1jo6 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1jo6 RCSB], [http://www.ebi.ac.uk/pdbsum/1jo6 PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=1jo6 ProSAT]</span></td></tr> | + | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Solution NMR</td></tr> |
| | + | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=1jo6 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1jo6 OCA], [https://pdbe.org/1jo6 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1jo6 RCSB], [https://www.ebi.ac.uk/pdbsum/1jo6 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1jo6 ProSAT]</span></td></tr> |
| | </table> | | </table> |
| | == Function == | | == Function == |
| - | [[http://www.uniprot.org/uniprot/KCMB2_HUMAN KCMB2_HUMAN]] Regulatory subunit of the calcium activated potassium KCNMA1 (maxiK) channel. Modulates the calcium sensitivity and gating kinetics of KCNMA1, thereby contributing to KCNMA1 channel diversity. Acts as a negative regulator that confers rapid and complete inactivation of KCNMA1 channel complex. May participate in KCNMA1 inactivation in chromaffin cells of the adrenal gland or in hippocampal CA1 neurons.<ref>PMID:10097176</ref> <ref>PMID:10377337</ref> | + | [https://www.uniprot.org/uniprot/KCMB2_HUMAN KCMB2_HUMAN] Regulatory subunit of the calcium activated potassium KCNMA1 (maxiK) channel. Modulates the calcium sensitivity and gating kinetics of KCNMA1, thereby contributing to KCNMA1 channel diversity. Acts as a negative regulator that confers rapid and complete inactivation of KCNMA1 channel complex. May participate in KCNMA1 inactivation in chromaffin cells of the adrenal gland or in hippocampal CA1 neurons.<ref>PMID:10097176</ref> <ref>PMID:10377337</ref> |
| | <div style="background-color:#fffaf0;"> | | <div style="background-color:#fffaf0;"> |
| | == Publication Abstract from PubMed == | | == Publication Abstract from PubMed == |
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| | | | |
| | ==See Also== | | ==See Also== |
| - | *[[Potassium Channel|Potassium Channel]] | + | *[[Potassium channel 3D structures|Potassium channel 3D structures]] |
| | == References == | | == References == |
| | <references/> | | <references/> |
| | __TOC__ | | __TOC__ |
| | </StructureSection> | | </StructureSection> |
| - | [[Category: Bentrop, D]] | + | [[Category: Homo sapiens]] |
| - | [[Category: Beyermann, M]] | + | [[Category: Large Structures]] |
| - | [[Category: Fakler, B]] | + | [[Category: Bentrop D]] |
| - | [[Category: Wissmann, R]] | + | [[Category: Beyermann M]] |
| - | [[Category: Cytoplasmic part of]] | + | [[Category: Fakler B]] |
| - | [[Category: Helix]] | + | [[Category: Wissmann R]] |
| - | [[Category: Ion channel]]
| + | |
| - | [[Category: Membrane protein]]
| + | |
| - | [[Category: Metal transport]]
| + | |
| Structural highlights
Function
KCMB2_HUMAN Regulatory subunit of the calcium activated potassium KCNMA1 (maxiK) channel. Modulates the calcium sensitivity and gating kinetics of KCNMA1, thereby contributing to KCNMA1 channel diversity. Acts as a negative regulator that confers rapid and complete inactivation of KCNMA1 channel complex. May participate in KCNMA1 inactivation in chromaffin cells of the adrenal gland or in hippocampal CA1 neurons.[1] [2]
Publication Abstract from PubMed
The auxiliary beta-subunit KCNMB2 (beta(2)) endows the non-inactivating large conductance Ca(2+)- and voltage-dependent potassium (BK) channel with fast inactivation. This process is mediated by the N terminus of KCNMB2 and closely resembles the "ball-and-chain"-type inactivation observed in voltage-gated potassium channels. Here we investigated the solution structure and function of the KCNMB2 N terminus (amino acids 1-45, BKbeta(2)N) using NMR spectroscopy and patch clamp recordings. BKbeta(2)N completely inactivated BK channels when applied to the cytoplasmic side; its interaction with the BK alpha-subunit is characterized by a particularly slow dissociation rate and an affinity in the upper nanomolar range. The BKbeta(2)N structure comprises two domains connected by a flexible linker: the pore-blocking "ball domain" (formed by residues 1-17) and the "chain domain" (between residues 20-45) linking it to the membrane segment of KCNMB2. The ball domain is made up of a flexible N terminus anchored at a well ordered loop-helix motif. The chain domain consists of a 4-turn helix with an unfolded linker at its C terminus. These structural properties explain the functional characteristics of BKbeta(2)N-mediated inactivation.
NMR structure of the "ball-and-chain" domain of KCNMB2, the beta 2-subunit of large conductance Ca2+- and voltage-activated potassium channels.,Bentrop D, Beyermann M, Wissmann R, Fakler B J Biol Chem. 2001 Nov 9;276(45):42116-21. Epub 2001 Aug 21. PMID:11517232[3]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Wallner M, Meera P, Toro L. Molecular basis of fast inactivation in voltage and Ca2+-activated K+ channels: a transmembrane beta-subunit homolog. Proc Natl Acad Sci U S A. 1999 Mar 30;96(7):4137-42. PMID:10097176
- ↑ Xia XM, Ding JP, Lingle CJ. Molecular basis for the inactivation of Ca2+- and voltage-dependent BK channels in adrenal chromaffin cells and rat insulinoma tumor cells. J Neurosci. 1999 Jul 1;19(13):5255-64. PMID:10377337
- ↑ Bentrop D, Beyermann M, Wissmann R, Fakler B. NMR structure of the "ball-and-chain" domain of KCNMB2, the beta 2-subunit of large conductance Ca2+- and voltage-activated potassium channels. J Biol Chem. 2001 Nov 9;276(45):42116-21. Epub 2001 Aug 21. PMID:11517232 doi:10.1074/jbc.M107118200
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