1UJB

Structure of the protein histidine phosphatase SixA


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.06 Å
  • R-Value Free: 0.229 
  • R-Value Work: 0.173 
  • R-Value Observed: 0.173 

wwPDB Validation   3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

Crystal structure of the protein histidine phosphatase SixA in the multistep His-Asp phosphorelay.

Hamada, K.Kato, M.Shimizu, T.Ihara, K.Mizuno, T.Hakoshima, T.

(2005) Genes Cells 10: 1-11

  • DOI: https://doi.org/10.1111/j.1365-2443.2005.00817.x
  • Primary Citation of Related Structures:  
    1UJB, 1UJC

  • PubMed Abstract: 

    The multiple histidine-aspartate phosphorelay system plays a crucial role in cellular adaptation to environments in microorganisms and plants. Like kinase-phosphatase systems in higher eukaryotes, the multiple steps provide additional regulatory checkpoints with phosphatases. The Escherichia coli phosphatase SixA exhibits protein phosphatase activity against the histidine-containing phosphotransfer (HPt) domain located in the C-terminus of the histidine kinase ArcB engaged in anaerobic responses. We have determined the crystal structures of the free and tungstate-bound forms of SixA at 2.06 A and 1.90 A resolution, respectively. The results provide the first three-dimensional view of a bacterial protein histidine phosphatase, revealing a compact alpha/beta architecture related to a family of phosphatases containing the arginine-histidine-glycine (RHG) motif at their active sites. Compared with these RHG phosphatases, SixA lacks an extra alpha-helical subdomain as a lid over the active site, thereby forming a relatively shallow groove important for the accommodation of the HPt domain of ArcB. The tungstate ion, which mimics the substrate phosphate group, is located at the centre of the active site where the active residue, His8, points to the tungsten atom in the mode of in-line nucleophilic attack.


  • Organizational Affiliation

    Structural Biology Laboratory, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192, Japan.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Phosphohistidine phosphatase sixA161Escherichia coliMutation(s): 0 
EC: 3.1.3
UniProt
Find proteins for P76502 (Escherichia coli (strain K12))
Explore P76502 
Go to UniProtKB:  P76502
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP76502
Sequence Annotations
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  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
CA
Query on CA

Download Ideal Coordinates CCD File 
B [auth A]CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.06 Å
  • R-Value Free: 0.229 
  • R-Value Work: 0.173 
  • R-Value Observed: 0.173 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 39.26α = 90
b = 48.62β = 90
c = 83.18γ = 90
Software Package:
Software NamePurpose
CNSrefinement
PROCESSdata reduction
CCP4data scaling
MLPHAREphasing
X-PLORrefinement

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2005-01-25
    Type: Initial release
  • Version 1.1: 2008-04-27
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2023-12-27
    Changes: Data collection, Database references, Derived calculations