6PBX

Single particle cryo-EM structure of the voltage-gated K+ channel Eag1 3-13 deletion mutant bound to calmodulin (conformation 2)

Summary for 6PBX

• Entry DOI: 10.2210/pdb6pbx/pdb
• EMDB information: 20294 20295
• Descriptor: Potassium voltage-gated channel subfamily H member 1, Calmodulin-1 (2 entities in total)
• Functional Keywords: voltage-gated potassium channel, ion channel, calmodulin, transport protein-calcium binding protein complex, transport protein/calcium binding protein
• Biological source: Rattus norvegicus (Rat); More
• Total number of polymer chains: 8
• Total formula weight: 452455.90

Authors

Whicher, J.R.,MacKinnon, R. (deposition date: 2019-06-14, release date: 2019-09-18, Last modification date: 2024-03-20)

Primary citation

Whicher, J.R.,MacKinnon, R.
Regulation of Eag1 gating by its intracellular domains.
Elife, 8:-, 2019

PubMed Abstract: Voltage-gated potassium channels (Ks) are gated by transmembrane voltage sensors (VS) that move in response to changes in membrane voltage. K10.1 or Eag1 also has three intracellular domains: PAS, C-linker, and CNBHD. We demonstrate that the Eag1 intracellular domains are not required for voltage-dependent gating but likely interact with the VS to modulate gating. We identified specific interactions between the PAS, CNBHD, and VS that modulate voltage-dependent gating and provide evidence that VS movement destabilizes these interactions to promote channel opening. Additionally, mutation of these interactions renders Eag1 insensitive to calmodulin inhibition. The structure of the calmodulin insensitive mutant in a pre-open conformation suggests that channel opening may occur through a rotation of the intracellular domains and calmodulin may prevent this rotation by stabilizing interactions between the VS and intracellular domains. Intracellular domains likely play a similar modulatory role in voltage-dependent gating of the related K11-12 channels.

PubMed: 31490124
DOI: 10.7554/eLife.49188

Experimental method

ELECTRON MICROSCOPY (4 Å)