8HA2

Crystal structure of voltage-gated sodium channel NavAb N49K/L176G mutant in calcium ion condition

Summary for 8HA2

• Entry DOI: 10.2210/pdb8ha2/pdb
• Descriptor: Ion transport protein, DODECYL-BETA-D-MALTOSIDE, CHAPSO, ... (6 entities in total)
• Functional Keywords: ion channel, membrane protein
• Biological source: Aliarcobacter butzleri
• Total number of polymer chains: 1
• Total formula weight: 38505.96

Authors

Irie, K.,Oda, Y. (deposition date: 2022-10-26, release date: 2023-07-26, Last modification date: 2024-05-29)

Primary citation

Irie, K.,Oda, Y.,Sumikama, T.,Oshima, A.,Fujiyoshi, Y.
The structural basis of divalent cation block in a tetrameric prokaryotic sodium channel.
Nat Commun, 14:4236-4236, 2023

PubMed Abstract: Divalent cation block is observed in various tetrameric ion channels. For blocking, a divalent cation is thought to bind in the ion pathway of the channel, but such block has not yet been directly observed. So, the behaviour of these blocking divalent cations remains still uncertain. Here, we elucidated the mechanism of the divalent cation block by reproducing the blocking effect into NavAb, a well-studied tetrameric sodium channel. Our crystal structures of NavAb mutants show that the mutations increasing the hydrophilicity of the inner vestibule of the pore domain enable a divalent cation to stack on the ion pathway. Furthermore, non-equilibrium molecular dynamics simulation showed that the stacking calcium ion repel sodium ion at the bottom of the selectivity filter. These results suggest the primary process of the divalent cation block mechanism in tetrameric cation channels.

PubMed: 37454189
DOI: 10.1038/s41467-023-39987-0

Experimental method

X-RAY DIFFRACTION (3.3 Å)