6NFU

Structure of the KcsA-G77A mutant or the 2,4-ion bound configuration of a K+ channel selectivity filter.


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.09 Å
  • R-Value Free: 0.224 
  • R-Value Work: 0.210 
  • R-Value Observed: 0.210 

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This is version 1.4 of the entry. See complete history


Literature

Structure, function, and ion-binding properties of a K+channel stabilized in the 2,4-ion-bound configuration.

Tilegenova, C.Cortes, D.M.Jahovic, N.Hardy, E.Hariharan, P.Guan, L.Cuello, L.G.

(2019) Proc Natl Acad Sci U S A 116: 16829-16834

  • DOI: https://doi.org/10.1073/pnas.1901888116
  • Primary Citation of Related Structures:  
    6NFU, 6NFV, 6PA0

  • PubMed Abstract: 

    Here, we present the atomic resolution crystallographic structure, the function, and the ion-binding properties of the KcsA mutants, G77A and G77C, that stabilize the 2,4-ion-bound configuration (i.e., water, K + , water, K + -ion-bound configuration) of the K + channel's selectivity filter. A full functional and thermodynamic characterization of the G77A mutant revealed wild-type-like ion selectivity and apparent K + -binding affinity, in addition to showing a lack of C-type inactivation gating and a marked reduction in its single-channel conductance. These structures validate, from a structural point of view, the notion that 2 isoenergetic ion-bound configurations coexist within a K + channel's selectivity filter, which fully agrees with the water-K + -ion-coupled transport detected by streaming potential measurements.


  • Organizational Affiliation

    Center for Membrane Protein Research, Texas Tech University Health Sciences Center, Lubbock, TX 79430.


Macromolecules
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Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
antibody fragment heavy chain219Mus musculusMutation(s): 0 
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  • Reference Sequence
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Entity ID: 2
MoleculeChains Sequence LengthOrganismDetailsImage
antibody fragment light chain212Mus musculusMutation(s): 0 
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  • Reference Sequence
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Entity ID: 3
MoleculeChains Sequence LengthOrganismDetailsImage
pH-gated potassium channel KcsA103Streptomyces lividansMutation(s): 2 
Gene Names: kcsAskc1
Membrane Entity: Yes 
UniProt
Find proteins for P0A334 (Streptomyces lividans)
Explore P0A334 
Go to UniProtKB:  P0A334
Entity Groups  
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UniProt GroupP0A334
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.09 Å
  • R-Value Free: 0.224 
  • R-Value Work: 0.210 
  • R-Value Observed: 0.210 
  • Space Group: I 4
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 155.086α = 90
b = 155.086β = 90
c = 75.794γ = 90
Software Package:
Software NamePurpose
HKL-2000data reduction
HKL-2000data scaling
PHENIXrefinement
PDB_EXTRACTdata extraction

Structure Validation

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Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)United States2R01GM097159-06
Robert A. Welch FoundationUnited StatesBI-1949
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)United StatesR01GM122759
National Institutes of Health/National Institute of Neurological Disorders and Stroke (NIH/NINDS)United StatesR21NS105863

Revision History  (Full details and data files)

  • Version 1.0: 2019-08-07
    Type: Initial release
  • Version 1.1: 2019-08-21
    Changes: Data collection, Database references
  • Version 1.2: 2019-08-28
    Changes: Data collection, Database references
  • Version 1.3: 2019-12-18
    Changes: Author supporting evidence
  • Version 1.4: 2023-10-11
    Changes: Data collection, Database references, Derived calculations, Refinement description