4HYO

Crystal Structure of MthK Pore

Summary for 4HYO

• Entry DOI: 10.2210/pdb4hyo/pdb
• Related: 4HZ3
• Descriptor: Calcium-gated potassium channel mthK, POTASSIUM ION, HEXANE-1,6-DIOL, ... (4 entities in total)
• Functional Keywords: transmembrane ion channel family, potassium channel, metal transport
• Biological source: Methanothermobacter thermautotrophicus
• Cellular location: Cell membrane; Multi-pass membrane protein: O27564
• Total number of polymer chains: 8
• Total formula weight: 82954.56

Authors

Posson, D.J.,McCoy, J.G.,Nimigean, C.M. (deposition date: 2012-11-13, release date: 2012-12-26, Last modification date: 2023-09-20)

Primary citation

Posson, D.J.,McCoy, J.G.,Nimigean, C.M.
The voltage-dependent gate in MthK potassium channels is located at the selectivity filter.
Nat.Struct.Mol.Biol., 20:159-166, 2013

PubMed Abstract: Understanding how ion channels open and close their pores is crucial for comprehending their physiological roles. We used intracellular quaternary ammonium blockers, electrophysiology and X-ray crystallography to locate the voltage-dependent gate in MthK potassium channels from Methanobacterium thermoautotrophicum. Blockers bind in an aqueous cavity between two putative gates: an intracellular gate and the selectivity filter. Thus, these blockers directly probe gate location--an intracellular gate will prevent binding when closed, whereas a selectivity filter gate will always allow binding. Kinetic analysis of tetrabutylammonium block of single MthK channels combined with X-ray crystallographic analysis of the pore with tetrabutyl antimony unequivocally determined that the voltage-dependent gate, like the C-type inactivation gate in eukaryotic channels, is located at the selectivity filter. State-dependent binding kinetics suggest that MthK inactivation leads to conformational changes within the cavity and intracellular pore entrance.

PubMed: 23262489
DOI: 10.1038/nsmb.2473

Experimental method

X-RAY DIFFRACTION (1.65 Å)