Skip to main content
Article thumbnail
Location of Repository

Crystal structure of full-length KcsA in its closed conformation

By Serdar Uysal, Valeria Vásquez, Valentina Tereshko, Kaori Esaki, Frederic A. Fellouse, Sachdev S. Sidhu, Shohei Koide, Eduardo Perozo and Anthony Kossiakoff


KcsA is a proton-activated, voltage-modulated K+ channel that has served as the archetype pore domain in the Kv channel superfamily. Here, we have used synthetic antigen-binding fragments (Fabs) as crystallographic chaperones to determine the structure of full-length KcsA at 3.8 Å, as well as that of its isolated C-terminal domain at 2.6 Å. The structure of the full-length KcsA–Fab complex reveals a well-defined, 4-helix bundle that projects ≈70 Å toward the cytoplasm. This bundle promotes a ≈15° bending in the inner bundle gate, tightening its diameter and shifting the narrowest point 2 turns of helix below. Functional analysis of the full-length KcsA–Fab complex suggests that the C-terminal bundle remains whole during gating. We suggest that this structure likely represents the physiologically relevant closed conformation of KcsA

Topics: Biological Sciences
Publisher: National Academy of Sciences
OAI identifier:
Provided by: PubMed Central
Download PDF:
Sorry, we are unable to provide the full text but you may find it at the following location(s):
  • http://www.pubmedcentral.nih.g... (external link)
  • Suggested articles

    To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.