4UUJ

POTASSIUM CHANNEL KCSA-FAB WITH TETRAHEXYLAMMONIUM

Summary for 4UUJ

• Entry DOI: 10.2210/pdb4uuj/pdb
• Descriptor: ANTIBODY FAB FRAGMENT LIGHT CHAIN, PHOSPHATE ION, ANTIBODY FAB FRAGMENT HEAVY CHAIN, ... (11 entities in total)
• Functional Keywords: immune system-metal transport complex, quaternary ammonium, protein-antibody fab complex, ionic channel, ion transport, potassium channel, immune system/metal transport
• Biological source: MUS MUSCULUS (HOUSE MOUSE); More
• Cellular location: Cell membrane; Multi-pass membrane protein: 4UUJ
• Total number of polymer chains: 3
• Total formula weight: 60873.44

Authors

Lenaeus, M.J.,Burdette, D.,Wagner, T.,Focia, P.J.,Gross, A. (deposition date: 2014-07-29, release date: 2014-08-27, Last modification date: 2024-10-16)

Primary citation

Lenaeus, M.J.,Burdette, D.,Wagner, T.,Focia, P.J.,Gross, A.
Structures of Kcsa in Complex with Symmetrical Quaternary Ammonium Compounds Reveal a Hydrophobic Binding Site.
Biochemistry, 53:5365-, 2014

PubMed Abstract: Potassium channels allow for the passive movement of potassium ions across the cell membrane and are instrumental in controlling the membrane potential in all cell types. Quaternary ammonium (QA) compounds block potassium channels and have long been used to study the functional and structural properties of these channels. Here we describe the interaction between three symmetrical hydrophobic QAs and the prokaryotic potassium channel KcsA. The structures demonstrate the presence of a hydrophobic pocket between the inner helices of KcsA and provide insight into the binding site and blocking mechanism of hydrophobic QAs. The structures also reveal a structurally hidden pathway between the central cavity and the outside membrane environment reminiscent of the lateral fenestration observed in sodium channels that can be accessed through small conformational changes in the pore wall. We propose that the hydrophobic binding pocket stabilizes the alkyl chains of long-chain QA molecules and may play a key role in hydrophobic drug binding in general.

PubMed: 25093676
DOI: 10.1021/BI500525S

Experimental method

X-RAY DIFFRACTION (2.4 Å)