2ISQ

Crystal Structure of O-Acetylserine Sulfhydrylase from Arabidopsis Thaliana in Complex with C-Terminal Peptide from Arabidopsis Serine Acetyltransferase


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.80 Å
  • R-Value Free: 0.248 
  • R-Value Work: 0.188 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Structural basis for interaction of o-acetylserine sulfhydrylase and serine acetyltransferase in the Arabidopsis cysteine synthase complex.

Francois, J.A.Kumaran, S.Jez, J.M.

(2006) Plant Cell 18: 3647-3655

  • DOI: 10.1105/tpc.106.047316
  • Primary Citation of Related Structures:  
    2ISQ

  • PubMed Abstract: 
  • In plants, association of O-acetylserine sulfhydrylase (OASS) and Ser acetyltransferase (SAT) into the Cys synthase complex plays a regulatory role in sulfur assimilation and Cys biosynthesis. We determined the crystal structure of Arabidopsis thalia ...

    In plants, association of O-acetylserine sulfhydrylase (OASS) and Ser acetyltransferase (SAT) into the Cys synthase complex plays a regulatory role in sulfur assimilation and Cys biosynthesis. We determined the crystal structure of Arabidopsis thaliana OASS (At-OASS) bound with a peptide corresponding to the C-terminal 10 residues of Arabidopsis SAT (C10 peptide) at 2.9-A resolution. Hydrogen bonding interactions with key active site residues (Thr-74, Ser-75, and Gln-147) lock the C10 peptide in the binding site. C10 peptide binding blocks access to OASS catalytic residues, explaining how complex formation downregulates OASS activity. Comparison with bacterial OASS suggests that structural plasticity in the active site allows binding of SAT C termini with dissimilar sequences at structurally similar OASS active sites. Calorimetric analysis of the effect of active site mutations (T74S, S75A, S75T, and Q147A) demonstrates that these residues are important for C10 peptide binding and that changes at these positions disrupt communication between active sites in the homodimeric enzyme. We also demonstrate that the C-terminal Ile of the C10 peptide is required for molecular recognition by At-OASS. These results provide new insights into the molecular mechanism underlying formation of the Cys synthase complex and provide a structural basis for the biochemical regulation of Cys biosynthesis in plants.


    Organizational Affiliation

    Donald Danforth Plant Science Center, St. Louis, Missouri 63132, USA.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Cysteine synthaseA320Arabidopsis thalianaMutation(s): 0 
Gene Names: OASA1OAS1OASSOLD3At4g14880dl3480c
EC: 2.5.1.47
Find proteins for P47998 (Arabidopsis thaliana)
Explore P47998 
Go to UniProtKB:  P47998
Protein Feature View
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  • Reference Sequence
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Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
Serine acetyltransferase 1B8Arabidopsis thalianaMutation(s): 0 
Gene Names: SAT1SAT5At1g55920F14J16.18
EC: 2.3.1.30
Find proteins for Q42588 (Arabidopsis thaliana)
Explore Q42588 
Go to UniProtKB:  Q42588
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
PLP
Query on PLP

Download CCD File 
A
PYRIDOXAL-5'-PHOSPHATE
C8 H10 N O6 P
NGVDGCNFYWLIFO-UHFFFAOYSA-N
 Ligand Interaction
SO4
Query on SO4

Download CCD File 
A
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.80 Å
  • R-Value Free: 0.248 
  • R-Value Work: 0.188 
  • Space Group: P 43 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 104.86α = 90
b = 104.86β = 90
c = 99.315γ = 90
Software Package:
Software NamePurpose
PROTEUM PLUSdata collection
CNSrefinement
SAINTdata reduction
PROTEUM PLUSdata scaling
CNSphasing

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2007-02-13
    Type: Initial release
  • Version 1.1: 2008-05-01
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Derived calculations, Version format compliance