Biological Assembly 1  

 3D View: Structure | Electron Density | Ligand Interaction

Global Symmetry: Dihedral - D4  (3D View)
Global Stoichiometry: Homo 8-mer - A8 

Biological assembly 1 assigned by authors and generated by PISA,PQS (software)

Macromolecule Content

• Total Structure Weight: 299.17 kDa 
• Atom Count: 16896 
• Residue Count: 2408 
• Unique protein chains: 1

1LNQ

CRYSTAL STRUCTURE OF MTHK AT 3.3 A

• DOI: 10.2210/pdb1LNQ/pdb

• Classification: METAL TRANSPORT
• Organism(s): Methanothermobacter thermautotrophicus
• Expression System: Escherichia coli
• Mutation(s): No 


• Deposited: 2002-05-03 Released: 2002-06-19 
• Deposition Author(s): Jiang, Y., Lee, A., Chen, J., Cadene, M., Chait, B.T., Mackinnon, R.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 3.30 Å
• R-Value Free: 0.318 
• R-Value Work: 0.301 
• R-Value Observed: 0.301 

Literature

CRYSTAL STRUCTURE AND MECHANISM OF A CALCIUM-GATED POTASSIUM CHANNEL

JIANG, Y., LEE, A., CHEN, J., CADENE, M., CHAIT, B.T., MACKINNON, R.

(2002) Nature 417: 515-522

• PubMed: 12037559 
• DOI: 10.1038/417515a
• Primary Citation of Related Structures:  
  1LNQ


• PubMed Abstract: 
  

Ion channels exhibit two essential biophysical properties; that is, selective ion conduction, and the ability to gate-open in response to an appropriate stimulus. Two general categories of ion channel gating are defined by the initiating stimulus: ligand binding (neurotransmitter- or second-messenger-gated channels) or membrane voltage (voltage-gated channels). Here we present the structural basis of ligand gating in a K(+) channel that opens in response to intracellular Ca(2+). We have cloned, expressed, analysed electrical properties, and determined the crystal structure of a K(+) channel (MthK) from Methanobacterium thermoautotrophicum in the Ca(2+)-bound, opened state. Eight RCK domains (regulators of K(+) conductance) form a gating ring at the intracellular membrane surface. The gating ring uses the free energy of Ca(2+) binding in a simple manner to perform mechanical work to open the pore.

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Related Citations: 

• THE OPEN PORE CONFORMATION OF POTASSIUM CHANNELS
  JIANG, Y., LEE, A., CHEN, J., CADENE, M., CHAIT, B.T., MACKINNON, R.
  (2002) Nature 417: 523

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Organizational Affiliation: 

Howard Hughes Medical Institute, Laboratory of Molecular Neurobiology and Biophysics, Rockefeller University, 1230 York Avenue, New York, New York 10021, USA.

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
POTASSIUM CHANNEL RELATED PROTEIN	A, B, C, D, E, F, G, H	336	Methanothermobacter thermautotrophicus	Mutation(s): 0  Gene Names: mth1520
Find proteins for O27564 (Methanothermobacter thermautotrophicus (strain ATCC 29096 / DSM 1053 / JCM 10044 / NBRC 100330 / Delta H)) Explore O27564  Go to UniProtKB:  O27564

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
CA	A, B, C, D, E, F, G, H	CALCIUM ION Ca BHPQYMZQTOCNFJ-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 3.30 Å
• R-Value Free: 0.318 
• R-Value Work: 0.301 
• R-Value Observed: 0.301 
• Space Group: P 6₁

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 137	α = 90
b = 137	β = 90
c = 373.3	γ = 120

Software Package:

Software Name	Purpose
SHARP	phasing
MLPHARE	phasing
CNS	refinement
HKL-2000	data reduction
SCALEPACK	data scaling

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2002-05-03 
• Released Date: 2002-06-19 
Deposition Author(s): Jiang, Y., Lee, A., Chen, J., Cadene, M., Chait, B.T., Mackinnon, R.

Revision History 

• Version 1.0: 2002-06-19
  Type: Initial release
  
• Version 1.1: 2007-10-16
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Derived calculations, Version format compliance
• Version 1.3: 2014-11-12
  Changes: Structure summary