3NWJ

Crystal structure of shikimate kinase from Arabidopsis thaliana (AtSK2)


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.35 Å
  • R-Value Free: 0.246 
  • R-Value Work: 0.191 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Structural and biochemical investigation of two Arabidopsis shikimate kinases: The heat-inducible isoform is thermostable.

Fucile, G.Garcia, C.Carlsson, J.Sunnerhagen, M.Christendat, D.

(2011) Protein Sci. 20: 1125-1136

  • DOI: 10.1002/pro.640

  • PubMed Abstract: 
  • The expression of plant shikimate kinase (SK; EC 2.7.1.71), an intermediate step in the shikimate pathway to aromatic amino acid biosynthesis, is induced under specific conditions of environmental stress and developmental requirements in an isoform-s ...

    The expression of plant shikimate kinase (SK; EC 2.7.1.71), an intermediate step in the shikimate pathway to aromatic amino acid biosynthesis, is induced under specific conditions of environmental stress and developmental requirements in an isoform-specific manner. Despite their important physiological role, experimental structures of plant SKs have not been determined and the biochemical nature of plant SK regulation is unknown. The Arabidopsis thaliana genome encodes two SKs, AtSK1 and AtSK2. We demonstrate that AtSK2 is highly unstable and becomes inactivated at 37 °C whereas the heat-induced isoform, AtSK1, is thermostable and fully active under identical conditions at this temperature. We determined the crystal structure of AtSK2, the first SK structure from the plant kingdom, and conducted biophysical characterizations of both AtSK1 and AtSK2 towards understanding this mechanism of thermal regulation. The crystal structure of AtSK2 is generally conserved with bacterial SKs with the addition of a putative regulatory phosphorylation motif forming part of the adenosine triphosphate binding site. The heat-induced isoform, AtSK1, forms a homodimer in solution, the formation of which facilitates its relative thermostability compared to AtSK2. In silico analyses identified AtSK1 site variants that may contribute to AtSK1 stability. Our findings suggest that AtSK1 performs a unique function under heat stress conditions where AtSK2 could become inactivated. We discuss these findings in the context of regulating metabolic flux to competing downstream pathways through SK-mediated control of steady state concentrations of shikimate.


    Organizational Affiliation

    Department of Cell and Systems Biology, University of Toronto, Ontario, Canada.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
AtSK2
A, B
250Arabidopsis thalianaMutation(s): 0 
Gene Names: SK2
EC: 2.7.1.71
Find proteins for Q8GY88 (Arabidopsis thaliana)
Go to UniProtKB:  Q8GY88
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.35 Å
  • R-Value Free: 0.246 
  • R-Value Work: 0.191 
  • Space Group: P 21 21 2
Unit Cell:
Length (Å)Angle (°)
a = 174.378α = 90.00
b = 62.249β = 90.00
c = 40.732γ = 90.00
Software Package:
Software NamePurpose
MOLREPphasing
ADSCdata collection
XDSdata reduction
REFMACrefinement
SCALAdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2011-06-29
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance