View source for 2le7


==Solution nmr structure of the S4S5 linker of herg potassium channel==
<StructureSection load='2le7' size='340' side='right'caption='[[2le7]]' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2le7]] 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=2LE7 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2LE7 FirstGlance]. <br>
</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=2le7 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2le7 OCA], [https://pdbe.org/2le7 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2le7 RCSB], [https://www.ebi.ac.uk/pdbsum/2le7 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2le7 ProSAT]</span></td></tr>
</table>
== Disease ==
[https://www.uniprot.org/uniprot/KCNH2_HUMAN KCNH2_HUMAN] Defects in KCNH2 are the cause of long QT syndrome type 2 (LQT2) [MIM:[https://omim.org/entry/613688 613688]. Long QT syndromes are heart disorders characterized by a prolonged QT interval on the ECG and polymorphic ventricular arrhythmias. They cause syncope and sudden death in response to exercise or emotional stress. Deafness is often associated with LQT2.<ref>PMID:16361248</ref> <ref>PMID:9600240</ref> <ref>PMID:7889573</ref> <ref>PMID:8914737</ref> <ref>PMID:8635257</ref> <ref>PMID:8877771</ref> <ref>PMID:9024139</ref> <ref>PMID:9693036</ref> <ref>PMID:9544837</ref> <ref>PMID:9452080</ref> <ref>PMID:10086971</ref> <ref>PMID:10220144</ref> <ref>PMID:10187793</ref> <ref>PMID:10517660</ref> <ref>PMID:10735633</ref> <ref>PMID:10973849</ref> <ref>PMID:10862094</ref> <ref>PMID:10753933</ref> <ref>PMID:12062363</ref> <ref>PMID:12354768</ref> <ref>PMID:12621127</ref> <ref>PMID:15051636</ref> <ref>PMID:15840476</ref> <ref>PMID:22314138</ref>   Defects in KCNH2 are the cause of short QT syndrome type 1 (SQT1) [MIM:[https://omim.org/entry/609620 609620]. Short QT syndromes are heart disorders characterized by idiopathic persistently and uniformly short QT interval on ECG in the absence of structural heart disease in affected individuals. They cause syncope and sudden death.<ref>PMID:14676148</ref> <ref>PMID:15828882</ref> 
== Function ==
[https://www.uniprot.org/uniprot/KCNH2_HUMAN KCNH2_HUMAN] Pore-forming (alpha) subunit of voltage-gated inwardly rectifying potassium channel. Channel properties are modulated by cAMP and subunit assembly. Mediates the rapidly activating component of the delayed rectifying potassium current in heart (IKr). Isoform 3 has no channel activity by itself, but modulates channel characteristics when associated with isoform 1.
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Human ether-a-go-go-related gene (hERG) K(+) channels have unusual gating kinetics. Characterised by slow activation/deactivation but rapid inactivation/recovery from inactivation, the unique gating kinetics underlie the central role hERG channels play in cardiac repolarisation. The slow activation and deactivation kinetics are regulated in part by the S4-S5 linker, which couples movement of the voltage sensor domain to opening of the activation gate at the distal end of the inner helix of the pore domain. It has also been suggested that cytosolic domains may interact with the S4-S5 linker to regulate activation and deactivation kinetics. Here, we show that the solution structure of a peptide corresponding to the S4-S5 linker of hERG contains an amphipathic helix. The effects of mutations at the majority of residues in the S4-S5 linker of hERG were consistent with the previously identified role in coupling voltage sensor movement to the activation gate. However, mutations to Ser543, Tyr545, Gly546 and Ala548 had more complex phenotypes indicating that these residues are involved in additional interactions. We propose a model in which the S4-S5 linker, in addition to coupling VSD movement to the activation gate, also contributes to interactions that stabilise the closed state and a separate set of interactions that stabilise the open state. The S4-S5 linker therefore acts as a signal integrator and plays a crucial role in the slow deactivation kinetics of the channel.

The S4-S5 linker acts as a signal integrator for HERG K+ channel activation and deactivation gating.,Ng CA, Perry MD, Tan PS, Hill AP, Kuchel PW, Vandenberg JI PLoS One. 2012;7(2):e31640. Epub 2012 Feb 16. PMID:22359612<ref>PMID:22359612</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 2le7" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Kuchel PW]]
[[Category: Ng CA]]
[[Category: Vandenberg JI]]