1X90

Crystal structure of mutant form B of a pectin methylesterase inhibitor from Arabidopsis


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.68 Å
  • R-Value Free: 0.256 
  • R-Value Work: 0.215 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Structural insights into the target specificity of plant invertase and pectin methylesterase inhibitory proteins

Hothorn, M.Wolf, S.Aloy, P.Greiner, S.Scheffzek, K.

(2004) Plant Cell 16: 3437-3447

  • DOI: 10.1105/tpc.104.025684
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Pectin methylesterase (PME) and invertase are key enzymes in plant carbohydrate metabolism. Inhibitors of both enzymes constitute a sequence family of extracellular proteins. Members of this family are selectively targeted toward either PME or invert ...

    Pectin methylesterase (PME) and invertase are key enzymes in plant carbohydrate metabolism. Inhibitors of both enzymes constitute a sequence family of extracellular proteins. Members of this family are selectively targeted toward either PME or invertase. In a comparative structural approach we have studied how this target specificity is implemented on homologous sequences. By extending crystallographic work on the invertase inhibitor Nt-CIF to a pectin methylesterase inhibitor (PMEI) from Arabidopsis thaliana, we show an alpha-helical hairpin motif to be an independent and mobile structural entity in PMEI. Removal of this hairpin fully inactivates the inhibitor. A chimera composed of the alpha-hairpin of PMEI and the four-helix bundle of Nt-CIF is still active against PME. By contrast, combining the corresponding segment of Nt-CIF with the four-helix bundle of PMEI renders the protein inactive toward either PME or invertase. Our experiments provide insight in how these homologous inhibitors can make differential use of similar structural modules to achieve distinct functions. Integrating our results with previous findings, we present a model for the PME-PMEI complex with important implications.


    Organizational Affiliation

    European Molecular Biology Laboratory, Structural and Computational Biology Programme, 69117 Heidelberg, Germany.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
invertase/pectin methylesterase inhibitor family protein
A, B
152Arabidopsis thalianaMutation(s): 1 
Gene Names: PMEI1
Find proteins for Q9LNF2 (Arabidopsis thaliana)
Go to UniProtKB:  Q9LNF2
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.68 Å
  • R-Value Free: 0.256 
  • R-Value Work: 0.215 
  • Space Group: H 3
Unit Cell:
Length (Å)Angle (°)
a = 82.410α = 90.00
b = 82.410β = 90.00
c = 105.410γ = 120.00
Software Package:
Software NamePurpose
XDSdata reduction
CNSrefinement
XDSdata scaling
CNSphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2004-12-28
    Type: Initial release
  • Version 1.1: 2008-04-30
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Derived calculations, Version format compliance