3K06

Crystal Structure of CNG mimicking NaK mutant, NaK-NTPP, K+ complex

3K06 の概要

• エントリーDOI: 10.2210/pdb3k06/pdb
• 関連するPDBエントリー: 3K0G 3k03 3k04 3k08 3k0d
• 分子名称: Potassium channel protein NaK, (4S)-2-METHYL-2,4-PENTANEDIOL, POTASSIUM ION, ... (4 entities in total)
• 機能のキーワード: nak-ntpp, ntpp, nak, cng mimicking, cng channel selectivity filter, nak-mutant, ionic channel, transport protein
• 由来する生物種: Bacillus cereus
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 22402.19

構造登録者

Jiang, Y.,Derebe, M.G. (登録日: 2009-09-24, 公開日: 2011-01-12, 最終更新日: 2024-02-21)

主引用文献

Derebe, M.G.,Zeng, W.,Li, Y.,Alam, A.,Jiang, Y.
Structural studies of ion permeation and Ca2+ blockage of a bacterial channel mimicking the cyclic nucleotide-gated channel pore.
Proc.Natl.Acad.Sci.USA, 108:592-597, 2011

PubMed Abstract: Cyclic nucleotide-gated (CNG) channels play an essential role in the visual and olfactory sensory systems and are ubiquitous in eukaryotes. Details of their underlying ion selectivity properties are still not fully understood and are a matter of debate in the absence of high-resolution structures. To reveal the structural mechanism of ion selectivity in CNG channels, particularly their Ca(2+) blockage property, we engineered a set of mimics of CNG channel pores for both structural and functional analysis. The mimics faithfully represent the CNG channels they are modeled after, permeate Na(+) and K(+) equally well, and exhibit the same Ca(2+) blockage and permeation properties. Their high-resolution structures reveal a hitherto unseen selectivity filter architecture comprising three contiguous ion binding sites in which Na(+) and K(+) bind with different ion-ligand geometries. Our structural analysis reveals that the conserved acidic residue in the filter is essential for Ca(2+) binding but not through direct ion chelation as in the currently accepted view. Furthermore, structural insight from our CNG mimics allows us to pinpoint equivalent interactions in CNG channels through structure-based mutagenesis that have previously not been predicted using NaK or K(+) channel models.

PubMed: 21187429
DOI: 10.1073/pnas.1013643108

実験手法

X-RAY DIFFRACTION (1.58 Å)