4f8a

</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=4f8a FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4f8a OCA], [https://pdbe.org/4f8a PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4f8a RCSB], [https://www.ebi.ac.uk/pdbsum/4f8a PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4f8a ProSAT]</span></td></tr>

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== Publication Abstract from PubMed ==

KCNH channels are voltage-gated potassium channels with important physiological functions. In these channels, a C-terminal cytoplasmic region, known as the cyclic nucleotide binding homology (CNB-homology) domain displays strong sequence similarity to cyclic nucleotide binding (CNB) domains. However, the isolated domain does not bind cyclic nucleotides. Here, we report the X-ray structure of the CNB-homology domain from the mouse EAG1 channel. Through comparison with the recently determined structure of the CNB-homology domain from the zebrafish ELK (eag-like K(+)) channel and the CNB domains from the MlotiK1 and HCN (hyperpolarization-activated cyclic nucleotide-gated) potassium channels, we establish the structural features of CNB-homology domains that explain the low affinity for cyclic nucleotides. Our structure establishes that the "self-liganded" conformation, where two residues of the C-terminus of the domain are bound in an equivalent position to cyclic nucleotides in CNB domains, is a conserved feature of CNB-homology domains. Importantly, we provide biochemical evidence that suggests that there is also an unliganded conformation where the C-terminus of the domain peels away from its bound position. A functional characterization of this unliganded conformation reveals a role of the CNB-homology domain in channel gating.

Structural, Biochemical, and Functional Characterization of the Cyclic Nucleotide Binding Homology Domain from the Mouse EAG1 Potassium Channel.,Marques-Carvalho MJ, Sahoo N, Muskett FW, Vieira-Pires RS, Gabant G, Cadene M, Schonherr R, Morais-Cabral JH J Mol Biol. 2012 Jun 23. PMID:22732247<ref>PMID:22732247</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>

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== References ==

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