Title: Conformational changes in the C terminus of Shaker K+ channel bound to the rat Kvbeta2-subunit.

Authors: Olga Sokolova, Alessio Accardi, David Gutierrez, Adrian Lau, Mike Rigney, Nikolaus Grigorieff

Journal, date & volume: Proc. Natl. Acad. Sci. U.S.A., 2003 Oct 28 , 100, 12607-12

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/14569011

Abstract
We studied the structure of the C terminus of the Shaker potassium channel. The 3D structures of the full-length and a C-terminal deletion (Delta C) mutant of Shaker were determined by electron microscopy and single-particle analysis. The difference map between the full-length and the truncated channels clearly shows a compact density, located on the sides of the T1 domain, that corresponds to a large part of the C terminus. We also expressed and purified both WT and Delta C Shaker, assembled with the rat KvBeta2-subunit. By using a difference map between the full-length and truncated Shaker alpha-beta complexes, a conformational change was identified that shifts a large part of the C terminus away from the membrane domain and into close contact with the Beta-subunit. This conformational change, induced by the binding of the KvBeta2-subunit, suggests a possible mechanism for the modulation of the K+ voltage-gated channel function by its Beta-subunit.