2bob

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Potassium channel KcsA-Fab complex in thallium with tetrabutylammonium (TBA)

Structural highlights

2bob is a 3 chain structure with sequence from Mus musculus and Streptomyces lividans. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:X-ray diffraction, Resolution 2.76Å
Ligands:CO, TBA, TL
Resources:FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

KCSA_STRLI Acts as a pH-gated potassium ion channel; changing the cytosolic pH from 7 to 4 opens the channel, although it is not clear if this is the physiological stimulus for channel opening. Monovalent cation preference is K(+) > Rb(+) > NH4(+) >> Na(+) > Li(+).[1]

Evolutionary Conservation

Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.

Publication Abstract from PubMed

Potassium channels catalyze the selective transfer of potassium across the cell membrane and are essential for setting the resting potential in cells, controlling heart rate and modulating the firing pattern in neurons. Tetraethylammonium (TEA) blocks ion conduction through potassium channels in a voltage-dependent manner from both sides of the membrane. Here we show the structural basis of TEA blockade by cocrystallizing the prokaryotic potassium channel KcsA with two selective TEA analogs. TEA binding at both sites alters ion occupancy in the selectivity filter; these findings underlie the mutual destabilization and voltage-dependence of TEA blockade. We propose that TEA blocks potassium channels by acting as a potassium analog at the dehydration transition step during permeation.

Structural basis of TEA blockade in a model potassium channel.,Lenaeus MJ, Vamvouka M, Focia PJ, Gross A Nat Struct Mol Biol. 2005 May;12(5):454-9. Epub 2005 Apr 24. PMID:15852022[2]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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Citations
11 reviews cite this structure
Optochemical genetics.
Fehrentz et al. (2011)
10 more
86 other articles
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See Also

References

  1. ↑ Schrempf H, Schmidt O, Kummerlen R, Hinnah S, Muller D, Betzler M, Steinkamp T, Wagner R. A prokaryotic potassium ion channel with two predicted transmembrane segments from Streptomyces lividans. EMBO J. 1995 Nov 1;14(21):5170-8. PMID:7489706
  2. ↑ Lenaeus MJ, Vamvouka M, Focia PJ, Gross A. Structural basis of TEA blockade in a model potassium channel. Nat Struct Mol Biol. 2005 May;12(5):454-9. Epub 2005 Apr 24. PMID:15852022 doi:10.1038/nsmb929

Contents


PDB ID 2bob

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