Crystal Structure of the Potassium Channel KirBac1.1 in the Closed State

Abstract

The KirBac1.1 channel belongs to the inward-rectifier family of potassium channels. Here we report the structure of the entire prokaryotic Kir channel assembly, in the closed state, refined to a resolution of 3.65 angstroms. We identify the main activation gate and structural elements involved in gating. On the basis of structural evidence presented here, we suggest that gating involves coupling between the intracellular and membrane domains. This further suggests that initiation of gating by membrane or intracellular signals represents different entry points to a common mechanistic pathway.

Functional analysis of six Kir6.2 (KCNJ11) mutations causing neonatal diabetes

“…In the 3-D structural model (Fig. 2b), H46 and N48 lie on a flexible loop that connects the cytosolic N terminus of the channel to the slide helix, an amphipathic helix that lies in the plane of the membrane and is postulated to be involved in gating of the channel [36]. Both residues lie in close proximity to residue R50, which is predicted to interact with the γ-phosphate of ATP (Fig.…”

Mutations in KCNJ11, which encodes Kir6.2, are a common cause of diabetes diagnosed in the first 6 months of life, with the phenotype determined by genotype

“…showing the 14 mutated residues. The illustration is based on the crystal structure of the potassium channel KirBac1.1 [25]. Each of the four subunits is represented by a different coloured ribbon structure (red, blue, lime, green).…”

The transmembrane topology of Batten disease protein CLN3 determined by consensus computational prediction constrained by experimental data

“…Helices that interact with the lipid bilayer are thought to modulate the activity of many ion channels [23,24]. The proposed amphipathic helix of CLN3 may act similarly and, if so, the local composition of the lipid membrane may influence function.…”