1G4Y

1.60 A CRYSTAL STRUCTURE OF THE GATING DOMAIN FROM SMALL CONDUCTANCE POTASSIUM CHANNEL COMPLEXED WITH CALCIUM-CALMODULIN

Summary for 1G4Y

• Entry DOI: 10.2210/pdb1g4y/pdb
• Descriptor: CALCIUM-ACTIVATED POTASSIUM CHANNEL RSK2, CALMODULIN, SULFATE ION, ... (5 entities in total)
• Functional Keywords: small-conductance calcium-activated potassium channel, calmodulin, calmodulin binding domain (cambd), channel gating, signaling protein
• Biological source: Rattus norvegicus (Norway rat); More
• Cellular location: Membrane; Multi-pass membrane protein: P70604; Cytoplasm, cytoskeleton, spindle: P62161
• Total number of polymer chains: 2
• Total formula weight: 29002.82

Authors

Schumacher, M.A.,Rivard, A.,Bachinger, H.P.,Adelman, J.P. (deposition date: 2001-01-07, release date: 2001-05-09, Last modification date: 2024-04-03)

Primary citation

Schumacher, M.A.,Rivard, A.F.,Bachinger, H.P.,Adelman, J.P.
Structure of the gating domain of a Ca2+-activated K+ channel complexed with Ca2+/calmodulin.
Nature, 410:1120-1124, 2001

PubMed Abstract: Small-conductance Ca2+-activated K+ channels (SK channels) are independent of voltage and gated solely by intracellular Ca2+. These membrane channels are heteromeric complexes that comprise pore-forming alpha-subunits and the Ca2+-binding protein calmodulin (CaM). CaM binds to the SK channel through the CaM-binding domain (CaMBD), which is located in an intracellular region of the alpha-subunit immediately carboxy-terminal to the pore. Channel opening is triggered when Ca2+ binds the EF hands in the N-lobe of CaM. Here we report the 1.60 A crystal structure of the SK channel CaMBD/Ca2+/CaM complex. The CaMBD forms an elongated dimer with a CaM molecule bound at each end; each CaM wraps around three alpha-helices, two from one CaMBD subunit and one from the other. As only the CaM N-lobe has bound Ca2+, the structure provides a view of both calcium-dependent and -independent CaM/protein interactions. Together with biochemical data, the structure suggests a possible gating mechanism for the SK channel.

PubMed: 11323678
DOI: 10.1038/35074145

Experimental method

X-RAY DIFFRACTION (1.6 Å)