Crystal Structure of the extracellular domain of the putative hybrid two component system BT3049 from B. thetaiotaomicron

Experimental Data Snapshot

  • Resolution: 3.30 Å
  • R-Value Free: 0.277 
  • R-Value Work: 0.225 
  • R-Value Observed: 0.228 

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Crystal structures of apparent saccharide sensors from histidine kinase receptors prevalent in a human gut symbiont.

Zhang, Z.Liu, Q.Hendrickson, W.A.

(2014) FEBS J 281: 4263-4279

  • DOI: https://doi.org/10.1111/febs.12904
  • Primary Citation of Related Structures:  
    3OTT, 3V9F

  • PubMed Abstract: 

    The adult human gut is a complicated ecosystem in which host-bacterium symbiosis plays an important role. Bacteroides thetaiotaomicron is a predominant member of the gut microflora, providing the human digestive tract with a large number of glycolytic enzymes. Expression of many of these enzymes appears to be controlled by histidine kinase receptors that are fused into unusual hybrid two-component systems that share homologous periplasmic sensor domains. These sensor domains belong to the third most populated (HK3) family based on a previous unpublished bioinformatics analysis of predicted histidine kinase sensors. Here, we present the crystal structures of two sensor domains representative of the HK3 family. Each sensor is folded into three domains: two-seven-bladed β-propeller domains and one β-sandwich domain. Both sensors form dimers in crystals, and one sensor appears to be physiologically relevant. The folding characteristics in the individual domains, the domain organization, and the oligomeric architecture are all unique to HK3 sensors. Sequence analysis of the HK3 sensors indicates that these sensor domains are shared among other signaling molecules, implying combinatorial molecular evolution.

  • Organizational Affiliation

    Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Two-component system sensor histidine kinase/response regulator, hybrid (One-component system)
A, B, C, D
781Bacteroides thetaiotaomicronMutation(s): 0 
Gene Names: BT_3049
Find proteins for Q8A3A5 (Bacteroides thetaiotaomicron (strain ATCC 29148 / DSM 2079 / JCM 5827 / CCUG 10774 / NCTC 10582 / VPI-5482 / E50))
Explore Q8A3A5 
Go to UniProtKB:  Q8A3A5
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ8A3A5
Sequence Annotations
  • Reference Sequence
Small Molecules
Modified Residues  1 Unique
IDChains TypeFormula2D DiagramParent
Query on MSE
A, B, C, D
Experimental Data & Validation

Experimental Data

  • Resolution: 3.30 Å
  • R-Value Free: 0.277 
  • R-Value Work: 0.225 
  • R-Value Observed: 0.228 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 79.927α = 90
b = 114.117β = 90
c = 487.47γ = 90
Software Package:
Software NamePurpose
PDB_EXTRACTdata extraction

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2012-03-14
    Type: Initial release
  • Version 1.1: 2014-07-23
    Changes: Database references
  • Version 1.2: 2014-10-08
    Changes: Database references