1XKL

Crystal Structure of Salicylic Acid-binding Protein 2 (SABP2) from Nicotiana tabacum, NESG Target AR2241


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å
  • R-Value Free: 0.234 
  • R-Value Work: 0.190 

wwPDB Validation 3D Report Full Report


This is version 1.4 of the entry. See complete history

Literature

Structural and biochemical studies identify tobacco SABP2 as a methyl salicylate esterase and implicate it in plant innate immunity

Forouhar, F.Yang, Y.Kumar, D.Chen, Y.Fridman, E.

(2005) Proc.Natl.Acad.Sci.USA 102: 1773-1778

  • DOI: 10.1073/pnas.0409227102
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Salicylic acid (SA) is a critical signal for the activation of plant defense responses against pathogen infections. We recently identified SA-binding protein 2 (SABP2) from tobacco as a protein that displays high affinity for SA and plays a crucial r ...

    Salicylic acid (SA) is a critical signal for the activation of plant defense responses against pathogen infections. We recently identified SA-binding protein 2 (SABP2) from tobacco as a protein that displays high affinity for SA and plays a crucial role in the activation of systemic acquired resistance to plant pathogens. Here we report the crystal structures of SABP2, alone and in complex with SA at up to 2.1-A resolution. The structures confirm that SABP2 is a member of the alpha/beta hydrolase superfamily of enzymes, with Ser-81, His-238, and Asp-210 as the catalytic triad. SA is bound in the active site and is completely shielded from the solvent, consistent with the high affinity of this compound for SABP2. Our biochemical studies reveal that SABP2 has strong esterase activity with methyl salicylate as the substrate, and that SA is a potent product inhibitor of this catalysis. Modeling of SABP2 with MeSA in the active site is consistent with all these biochemical observations. Our results suggest that SABP2 may be required to convert MeSA to SA as part of the signal transduction pathways that activate systemic acquired resistance and perhaps local defense responses as well.


    Organizational Affiliation

    Department of Biological Sciences, Northeast Structural Genomics Consortium, Columbia University, New York, NY 10027, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
salicylic acid-binding protein 2
A, B, C, D
273Nicotiana tabacumMutation(s): 0 
Gene Names: SABP2
EC: 3.1.1.-
Find proteins for Q6RYA0 (Nicotiana tabacum)
Go to UniProtKB:  Q6RYA0
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
STH
Query on STH

Download SDF File 
Download CCD File 
A, B, C, D
2-AMINO-4H-1,3-BENZOXATHIIN-4-OL
C8 H9 N O2 S
DVFUKUONLVBBEH-SFYZADRCSA-N
 Ligand Interaction
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
MSE
Query on MSE
A, B, C, D
L-PEPTIDE LINKINGC5 H11 N O2 SeMET
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å
  • R-Value Free: 0.234 
  • R-Value Work: 0.190 
  • Space Group: P 21 21 2
Unit Cell:
Length (Å)Angle (°)
a = 136.457α = 90.00
b = 167.773β = 90.00
c = 44.831γ = 90.00
Software Package:
Software NamePurpose
SCALEPACKdata scaling
CNSrefinement
DENZOdata reduction
SnBphasing
SOLVEphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2004-11-30
    Type: Initial release
  • Version 1.1: 2008-04-30
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance
  • Version 1.3: 2011-11-16
    Type: Atomic model
  • Version 1.4: 2017-10-11
    Type: Refinement description