6MNI

Structure of the tandem CACHE domain of PscC


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.70 Å
  • R-Value Free: 0.200 
  • R-Value Work: 0.162 
  • R-Value Observed: 0.164 

Starting Model: experimental
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This is version 1.2 of the entry. See complete history


Literature

Structure of a double CACHE chemoreceptor ligand-binding domain from Pseudomonas syringae provides insights into the basis of proline recognition.

Ehrhardt, M.K.G.Gerth, M.L.Johnston, J.M.

(2021) Biochem Biophys Res Commun 549: 194-199

  • DOI: https://doi.org/10.1016/j.bbrc.2021.02.090
  • Primary Citation of Related Structures:  
    6MNI

  • PubMed Abstract: 

    Chemotaxis is the process of sensing chemical gradients and navigating towards favourable conditions. Bacterial chemotaxis is mediated by arrays of trans-membrane chemoreceptor proteins. The most common class of chemoreceptors have periplasmic ligand-binding domains (LBDs) that detect extracellular chemical signs and transduce these signals to the downstream chemotaxis machinery. The repertoire of chemoreceptor proteins in a bacterium determines the range of environmental signals to which it can respond. Pseudomonas syringae pv. actinidiae (Psa) is a plant pathogen which causes bacterial canker of kiwifruit (Actinidia sp.). Compared to many other bacteria, Psa has a large number of chemoreceptors encoded in its genome (43) and most of these remain uncharacterized. A previous study identified PscC as a potential chemoreceptor for l-proline and other amino acid ligands. Here, we have characterized the interaction of PscC-LBD with l-proline using a combination of isothermal titration calorimetry (ITC) and X-ray crystallography. ITC confirmed direct binding of l-proline to PscC-LBD with K D value of 5.0 μM. We determined the structure of PscC-LBD in complex with l-proline. Our structural analysis showed that PscC-LBD adopts similar double-CACHE fold to several other amino acid chemoreceptors. A comparison of the PscC-LDB to other dCACHE structures highlights residues in the binding cavity which contribute to its ligand specificity.


  • Organizational Affiliation

    Department of Biochemistry, University of Otago, Dunedin, New Zealand.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Methyl-accepting chemotaxis protein
A, B
287Pseudomonas syringae pv. actinidiaeMutation(s): 0 
Gene Names: KPSA3_03559
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.70 Å
  • R-Value Free: 0.200 
  • R-Value Work: 0.162 
  • R-Value Observed: 0.164 
  • Space Group: P 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 34.244α = 104.79
b = 53.916β = 91.2
c = 73.312γ = 92.71
Software Package:
Software NamePurpose
XDSdata reduction
Aimlessdata scaling
PHENIXrefinement
PDB_EXTRACTdata extraction
BALBESphasing

Structure Validation

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Ligand Structure Quality Assessment 


Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2019-10-16
    Type: Initial release
  • Version 1.1: 2021-04-28
    Changes: Database references
  • Version 1.2: 2023-10-11
    Changes: Data collection, Database references, Refinement description