Globin sensor domain of AfGcHK in monomeric form, with imidazole

Experimental Data Snapshot

  • Resolution: 1.80 Å
  • R-Value Free: 0.231 
  • R-Value Work: 0.182 
  • R-Value Observed: 0.186 

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This is version 1.3 of the entry. See complete history


Disruption of the dimerization interface of the sensing domain in the dimeric heme-based oxygen sensorAfGcHK abolishes bacterial signal transduction.

Skalova, T.Lengalova, A.Dohnalek, J.Harlos, K.Mihalcin, P.Kolenko, P.Stranava, M.Blaha, J.Shimizu, T.Martinkova, M.

(2020) J Biol Chem 295: 1587-1597

  • DOI: https://doi.org/10.1074/jbc.RA119.011574
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    The heme-based oxygen sensor protein Af GcHK is a globin-coupled histidine kinase in the soil bacterium Anaeromyxobacter sp. Fw109-5. Its C-terminal functional domain exhibits autophosphorylation activity induced by oxygen binding to the heme-Fe(II) complex located in the oxygen-sensing N-terminal globin domain. A detailed understanding of the signal transduction mechanisms in heme-containing sensor proteins remains elusive. Here, we investigated the role of the globin domain's dimerization interface in signal transduction in Af GcHK. We present a crystal structure of a monomeric imidazole-bound Af GcHK globin domain at 1.8 Å resolution, revealing that the helices of the WT globin dimer are under tension and suggesting that Tyr-15 plays a role in both this tension and the globin domain's dimerization. Biophysical experiments revealed that whereas the isolated WT globin domain is dimeric in solution, the Y15A and Y15G variants in which Tyr-15 is replaced with Ala or Gly, respectively, are monomeric. Additionally, we found that although the dimerization of the full-length protein is preserved via the kinase domain dimerization interface in all variants, full-length Af GcHK variants bearing the Y15A or Y15G substitutions lack enzymatic activity. The combined structural and biophysical results presented here indicate that Tyr-15 plays a key role in the dimerization of the globin domain of Af GcHK and that globin domain dimerization is essential for internal signal transduction and autophosphorylation in this protein. These findings provide critical insights into the signal transduction mechanism of the histidine kinase Af GcHK from Anaeromyxobacter .

  • Organizational Affiliation

    Institute of Biotechnology of the Czech Academy of Sciences, v.v.i., Biocev, Vestec, 252 50 Czech Republic.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Globin-coupled histidine kinase161Anaeromyxobacter sp. Fw109-5Mutation(s): 0 
Gene Names: gchKAnae109_2438
Find proteins for A7HD43 (Anaeromyxobacter sp. (strain Fw109-5))
Explore A7HD43 
Go to UniProtKB:  A7HD43
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupA7HD43
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

Unit Cell:
Length ( Å )Angle ( ˚ )
a = 69.44α = 90
b = 69.44β = 90
c = 113.364γ = 120
Software Package:
Software NamePurpose
XDSdata reduction
Aimlessdata scaling

Structure Validation

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Ligand Structure Quality Assessment 

Entry History & Funding Information

Deposition Data

Funding OrganizationLocationGrant Number
Ministry of Education (MoE, Czech Republic)Czech RepublicLM2015043
European Regional Development FundCzech RepublicCZ.02.1.01/0.0/0.0/16_013/0001776

Revision History  (Full details and data files)

  • Version 1.0: 2020-01-08
    Type: Initial release
  • Version 1.1: 2020-01-22
    Changes: Database references
  • Version 1.2: 2020-02-19
    Changes: Database references
  • Version 1.3: 2023-10-11
    Changes: Data collection, Database references, Refinement description