Biological Assembly 1  

 3D View: Structure | 1D-3D View | Electron Density | Validation Report | Ligand Interaction

Global Symmetry: Cyclic - C2  (3D View)
Global Stoichiometry: Homo 2-mer - A2 

Biological assembly 1 assigned by authors and generated by PISA (software)

Macromolecule Content

• Total Structure Weight: 77.81 kDa 
• Atom Count: 5921 
• Modelled Residue Count: 672 
• Deposited Residue Count: 684 
• Unique protein chains: 1

3IT3

Crystal Structure Francisella tularensis histidine acid phosphatase D261A mutant complexed with substrate 3'-AMP

• PDB DOI: 10.2210/pdb3IT3/pdb

• Classification: HYDROLASE
• Organism(s): Francisella tularensis subsp. holarctica LVS
• Expression System: Escherichia coli
• Mutation(s): Yes 


• Deposited: 2009-08-27 Released: 2009-11-10 
• Deposition Author(s): Singh, H., Felts, R.L., Reilly, T.J., Tanner, J.J.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 1.50 Å
• R-Value Free: 0.187 
• R-Value Work: 0.172 
• R-Value Observed: 0.172 

Literature

Crystal Structures of the histidine acid phosphatase from Francisella tularensis provide insight into substrate recognition.

Singh, H., Felts, R.L., Schuermann, J.P., Reilly, T.J., Tanner, J.J.

(2009) J Mol Biol 394: 893-904

• PubMed: 19836403 
• DOI: 10.1016/j.jmb.2009.10.009
• Primary Citation of Related Structures:  
  3IT0, 3IT1, 3IT2, 3IT3


• PubMed Abstract: 
  

Histidine acid phosphatases catalyze the transfer of a phosphoryl group from phosphomonoesters to water at acidic pH using an active-site histidine. The histidine acid phosphatase from the category A pathogen Francisella tularensis (FtHAP) has been implicated in intramacrophage survival and virulence, motivating interest in understanding the structure and mechanism of this enzyme. Here, we report a structure-based study of ligand recognition by FtHAP. The 1.70-A-resolution structure of FtHAP complexed with the competitive inhibitor l(+)-tartrate was solved using single-wavelength anomalous diffraction phasing. Structures of the ligand-free enzyme and the complex with inorganic phosphate were determined at resolutions of 1.85 and 1.70 A, respectively. The structure of the Asp261Ala mutant enzyme complexed with the substrate 3'-AMP was determined at 1.50 A resolution to gain insight into substrate recognition. FtHAP exhibits a two-domain fold similar to that of human prostatic acid phosphatase, consisting of an alpha/beta core domain and a smaller domain that caps the core domain. The structures show that the core domain supplies the phosphoryl binding site, catalytic histidine (His17), and an aspartic acid residue (Asp261) that protonates the leaving group, while the cap domain contributes residues that enforce substrate preference. FtHAP and human prostatic acid phosphatase differ in the orientation of the crucial first helix of the cap domain, implying differences in the substrate preferences of the two enzymes. 3'-AMP binds in one end of a 15-A-long tunnel, with the adenine clamped between Phe23 and Tyr135, and the ribose 2'-hydroxyl interacting with Gln132. The importance of the clamp is confirmed with site-directed mutagenesis; mutation of Phe23 and Tyr135 individually to Ala increases K(m) by factors of 7 and 10, respectively. The structural data are consistent with a role for FtHAP in scavenging phosphate from small molecules present in host macrophage cells.

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Organizational Affiliation: 

Department of Chemistry, University of Missouri-Columbia, Columbia, MO 65211, USA.

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Acid phosphatase	A, B	342	Francisella tularensis subsp. holarctica LVS	Mutation(s): 1  Gene Names: FTL_0031 EC: 3.1.3.2

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
3AM	C [auth A], D [auth B]	[(2R,3S,4R,5R)-5-(6-aminopurin-9-yl)-4-hydroxy-2-(hydroxymethyl)oxolan-3-yl] dihydrogen phosphate C10 H14 N5 O7 P LNQVTSROQXJCDD-KQYNXXCUSA-N

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 1.50 Å
• R-Value Free: 0.187 
• R-Value Work: 0.172 
• R-Value Observed: 0.172 
• Space Group: P 4₁

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 61.646	α = 90
b = 61.646	β = 90
c = 211.439	γ = 90

Software Package:

Software Name	Purpose
DENZO	data reduction
SCALEPACK	data scaling
PHENIX	refinement
PDB_EXTRACT	data extraction
HKL-2000	data reduction
HKL-2000	data scaling
PHENIX	phasing

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2009-08-27 
• Released Date: 2009-11-10 
Deposition Author(s): Singh, H., Felts, R.L., Reilly, T.J., Tanner, J.J.

Revision History  

• Version 1.0: 2009-11-10
  Type: Initial release
  
• Version 1.1: 2011-07-13
  Changes: Source and taxonomy, Version format compliance
• Version 1.2: 2017-11-01
  Changes: Advisory, Refinement description
• Version 1.3: 2021-10-13
  Changes: Advisory, Database references, Derived calculations