1A68

CRYSTAL STRUCTURE OF THE TETRAMERIZATION DOMAIN OF THE SHAKER POTASSIUM CHANNEL

Summary for 1A68

• Entry DOI: 10.2210/pdb1a68/pdb
• Descriptor: POTASSIUM CHANNEL KV1.1 (2 entities in total)
• Functional Keywords: potassium channels, tetramerization domain, aplysia kv1.1
• Biological source: Aplysia californica (California sea hare)
• Total number of polymer chains: 1
• Total formula weight: 11493.91

Authors

Kreusch, A.,Pfaffinger, P.J.,Stevens, C.F.,Choe, S. (deposition date: 1998-03-06, release date: 1998-06-10, Last modification date: 2024-02-07)

Primary citation

Kreusch, A.,Pfaffinger, P.J.,Stevens, C.F.,Choe, S.
Crystal structure of the tetramerization domain of the Shaker potassium channel.
Nature, 392:945-948, 1998

PubMed Abstract: Voltage-dependent, ion-selective channels such as Na+, Ca2+ and K+ channel proteins function as tetrameric assemblies of identical or similar subunits. The clustering of four subunits is thought to create an aqueous pore centred at the four-fold symmetry axis. The highly conserved, amino-terminal cytoplasmic domain (approximately 130 amino acids) immediately preceding the first putative transmembrane helix S1 is designated T1. It is known to confer specificity for tetramer formation, so the heteromeric assembly of K+-channel subunits is an important mechanism for the observed channel diversity. We have determined the crystal structure of the T1 domain of a Shaker potassium channel at 1.55 A resolution. The structure reveals that four identical subunits are arranged in a four-fold symmetry surrounding a centrally located pore about 20 A in length. Subfamily-specific assembly is provided primarily by polar interactions encoded in a conserved set of amino acids at its tetramerization interface. Most highly conserved amino acids in the T1 domain of all known potassium channels are found in the core of the protein, indicating a common structural framework for the tetramer assembly.

PubMed: 9582078
DOI: 10.1038/31978

Experimental method

X-RAY DIFFRACTION (1.8 Å)