The kinase domain of Escherichia coli tyrosine kinase ETK

Experimental Data Snapshot

  • Resolution: 2.50 Å
  • R-Value Free: 0.254 
  • R-Value Work: 0.196 
  • R-Value Observed: 0.196 

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Structure of Escherichia coli tyrosine kinase Etk reveals a novel activation mechanism.

Lee, D.C.Zheng, J.She, Y.M.Jia, Z.

(2008) EMBO J 27: 1758-1766

  • DOI: https://doi.org/10.1038/emboj.2008.97
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    While protein tyrosine (Tyr) kinases (PTKs) have been extensively characterized in eukaryotes, far less is known about their emerging counterparts in prokaryotes. The inner-membrane Wzc/Etk protein belongs to the bacterial PTK family, which has an important function in regulating the polymerization and transport of virulence-determining capsular polysaccharide (CPS). The kinase uses a unique two-step activation process involving intra-phosphorylation of a Tyr residue, although the molecular mechanism remains unknown. Herein, we report the first crystal structure of a bacterial PTK, the C-terminal kinase domain of Escherichia coli Tyr kinase (Etk) at 2.5-A resolution. The fold of the Etk kinase domain differs markedly from that of eukaryotic PTKs. Based on the observed structure and supporting mass spectrometric evidence of Etk, a unique activation mechanism is proposed that involves the phosphorylated Tyr residue, Y574, at the active site and its specific interaction with a previously unidentified key Arg residue, R614, to unblock the active site. Both in vitro kinase activity and in vivo antibiotics resistance studies using structure-guided mutants further support the novel activation mechanism.

  • Organizational Affiliation

    Department of Biochemistry, Queen's University, Kingston, Ontario, Canada.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Tyrosine-protein kinase etkA,
B [auth D]
299Escherichia coliMutation(s): 0 
Gene Names: etkyccC
Find proteins for P38134 (Escherichia coli (strain K12))
Explore P38134 
Go to UniProtKB:  P38134
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP38134
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 2.50 Å
  • R-Value Free: 0.254 
  • R-Value Work: 0.196 
  • R-Value Observed: 0.196 
  • Space Group: C 1 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 115.514α = 90
b = 51.731β = 114.57
c = 120.519γ = 90
Software Package:
Software NamePurpose
HKL-2000data reduction
SCALEPACKdata scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2008-06-03
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance
  • Version 1.2: 2024-02-21
    Changes: Data collection, Database references, Derived calculations