Conformational changes in the C-terminus of Shaker K+ channel bound to the rat Kvbeta2-subunit
Publication Type
Journal Article
Year of Publication
2003
Refereed Designation
Refereed
Journal
Proc Natl Acad Sci U S A
Volume
100
Pagination
12607-12
Date Published
Oct 28
ISSN
0027-8424 (Print)
Accession Number
14569011
Citation Key
72
Number
22
Keywords
"*Potassium Channels, Voltage-Gated", *Protein Conformation, Animals, Binding Sites, Cercopithecus aethiops, COS Cells, Fourier Analysis, "Models, Molecular", Peptide Fragments/chemistry, Potassium Channels/*chemistry/genetics, Protein Subunits/chemistry,
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.
