3SYC

Crystal structure of the G protein-gated inward rectifier K+ channel GIRK2 (Kir3.2) D228N mutant

Summary for 3SYC

• Entry DOI: 10.2210/pdb3syc/pdb
• Related: 3SYA 3SYO 3SYP 3SYQ
• Descriptor: G protein-activated inward rectifier potassium channel 2, POTASSIUM ION (2 entities in total)
• Functional Keywords: ion channel, potassium channel, inward rectification, sodium binding, pip2 binding, g protein binding, metal transport
• Biological source: Mus musculus (mouse)
• Cellular location: Membrane; Multi-pass membrane protein: P48542
• Total number of polymer chains: 1
• Total formula weight: 39295.56

Authors

Whorton, M.R.,MacKinnon, R. (deposition date: 2011-07-16, release date: 2011-10-12, Last modification date: 2024-10-30)

Primary citation

Whorton, M.R.,Mackinnon, R.
Crystal Structure of the Mammalian GIRK2 K(+) Channel and Gating Regulation by G Proteins, PIP(2), and Sodium.
Cell(Cambridge,Mass.), 147:199-208, 2011

PubMed Abstract: G protein-gated K(+) channels (Kir3.1-Kir3.4) control electrical excitability in many different cells. Among their functions relevant to human physiology and disease, they regulate the heart rate and govern a wide range of neuronal activities. Here, we present the first crystal structures of a G protein-gated K(+) channel. By comparing the wild-type structure to that of a constitutively active mutant, we identify a global conformational change through which G proteins could open a G loop gate in the cytoplasmic domain. The structures of both channels in the absence and presence of PIP(2) suggest that G proteins open only the G loop gate in the absence of PIP(2), but in the presence of PIP(2) the G loop gate and a second inner helix gate become coupled, so that both gates open. We also identify a strategically located Na(+) ion-binding site, which would allow intracellular Na(+) to modulate GIRK channel activity. These data provide a structural basis for understanding multiligand regulation of GIRK channel gating.

PubMed: 21962516
DOI: 10.1016/j.cell.2011.07.046

Experimental method

X-RAY DIFFRACTION (3.41 Å)