5J9P

KcsA in vitro


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.85 Å
  • R-Value Free: 0.266 
  • R-Value Work: 0.217 
  • R-Value Observed: 0.222 

wwPDB Validation   3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

Combining in Vitro Folding with Cell Free Protein Synthesis for Membrane Protein Expression.

Focke, P.J.Hein, C.Hoffmann, B.Matulef, K.Bernhard, F.Dotsch, V.Valiyaveetil, F.I.

(2016) Biochemistry 55: 4212-4219

  • DOI: https://doi.org/10.1021/acs.biochem.6b00488
  • Primary Citation of Related Structures:  
    5J9P

  • PubMed Abstract: 

    Cell free protein synthesis (CFPS) has emerged as a promising methodology for protein expression. While polypeptide production is very reliable and efficient using CFPS, the correct cotranslational folding of membrane proteins during CFPS is still a challenge. In this contribution, we describe a two-step protocol in which the integral membrane protein is initially expressed by CFPS as a precipitate followed by an in vitro folding procedure using lipid vesicles for converting the protein precipitate to the correctly folded protein. We demonstrate the feasibility of using this approach for the K(+) channels KcsA and MVP and the amino acid transporter LeuT. We determine the crystal structure of the KcsA channel obtained by CFPS and in vitro folding to show the structural similarity to the cellular expressed KcsA channel and to establish the feasibility of using this two-step approach for membrane protein production for structural studies. Our studies show that the correct folding of these membrane proteins with complex topologies can take place in vitro without the involvement of the cellular machinery for membrane protein biogenesis. This indicates that the folding instructions for these complex membrane proteins are contained entirely within the protein sequence.


  • Organizational Affiliation

    Program in Chemical Biology, Department of Physiology and Pharmacology, Oregon Health & Science University , 3181 Southwest Sam Jackson Park Road, Portland, Oregon 97239, United States.


Macromolecules
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Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Fab219Mus musculusMutation(s): 0 
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  • Reference Sequence
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Entity ID: 2
MoleculeChains Sequence LengthOrganismDetailsImage
Fab212Mus musculusMutation(s): 0 
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  • Reference Sequence
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Entity ID: 3
MoleculeChains Sequence LengthOrganismDetailsImage
pH-gated potassium channel KcsA96Streptomyces lividansMutation(s): 0 
Membrane Entity: Yes 
UniProt
Find proteins for P0A334 (Streptomyces lividans)
Explore P0A334 
Go to UniProtKB:  P0A334
Entity Groups  
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UniProt GroupP0A334
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.85 Å
  • R-Value Free: 0.266 
  • R-Value Work: 0.217 
  • R-Value Observed: 0.222 
  • Space Group: I 4
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 155.695α = 90
b = 155.695β = 90
c = 74.791γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
SCALAdata scaling
PDB_EXTRACTdata extraction
XDSdata reduction
PHASERphasing

Structure Validation

View Full Validation Report



Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)United States--

Revision History  (Full details and data files)

  • Version 1.0: 2016-07-20
    Type: Initial release
  • Version 1.1: 2016-08-10
    Changes: Database references
  • Version 1.2: 2017-09-27
    Changes: Author supporting evidence, Database references, Derived calculations
  • Version 1.3: 2019-12-04
    Changes: Author supporting evidence