Cryo-EM structure of the human inward-rectifier potassium 2.1 channel (Kir2.1)

Cryo-electron microscopy unveils unique structural features of the human Kir2.1 channel.

For structural fitting, it was used dock-in-map (available at PHENIX) that uses both SSM and convolution-based shape searches to find a part of a map that is similar to a model. An initial in silico homology model of human Kir2.1 was generated using I-TASSER using the crystal structure of chicken Kir2.2 channel (PDB ID 3JYC) as a template. For building and refinement of the atomic model, the transmembrane domain (TMD, 55-184 region) of this in silico model was placed into the final sharpened cryo-EM map using the Dock in Map tool available in PHENIX. For the cytoplasmic domain (CTD; 188-367 region), the crystal structure of the CTD from mice Kir2.1 channel (PDB ID 1U4F) was placed into the final cryo-EM map using the same approach. Once the models were placed in the electron density, the loops that connect the two domains (185-187 region) and a N-terminal loop (41-54 region) absent in the in silico model were manually built using Coot.

Human inward-rectifier potassium channel 2.1 (Kir2.1)

Cardiac inward rectifier potassium channel,Inward rectifier K(+) channel Kir2.1,IRK-1,hIRK1,Potassium channel,inwardly rectifying subfamily J member 2

The French Muscular Dystrophy Telethon (AFM-Telethon)

Potassium channel, Inward-rectifier channel, inward rectification, MEMBRANE PROTEIN