Referenced in: none

Automatically associated channels: Kv11.1 , Slo1

Title: NMR solution structure of the N-terminal domain of hERG and its interaction with the S4-S5 linker.

Authors: Qingxin Li, Shovanlal Gayen, Angela Shuyi Chen, Qiwei Huang, Manfred Raida, Congbao Kang

Journal, date & volume: Biochem. Biophys. Res. Commun., 2010 Dec 3 , 403, 126-32

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/21055387

Abstract
The human Ether-à-go-go Related Gene (hERG) potassium channel mediates the rapid delayed rectifier current (IKr) in the cardiac action potential. Mutations in the 135 amino acid residue N-terminal domain (NTD) cause channel dysfunction or mis-translocation. To study the structure of NTD, it was overexpressed and purified from Escherichia coli cells using affinity purification and gel filtration chromatography. The purified protein behaved as a monomer under purification conditions. Far- and near-UV, circular dichroism (CD) and solution nuclear magnetic resonance (NMR) studies showed that the purified protein was well-folded. The solution structure of NTD was obtained and the N-terminal residues 13-23 forming an amphipathic helix which may be important for the protein-protein or protein-membrane interactions. NMR titration experiment also demonstrated that residues from 88 to 94 in NTD are important for the molecular interaction with the peptide derived from the S4-S5 linker.