4N6A

Soybean Serine Acetyltransferase Apoenzyme


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.75 Å
  • R-Value Free: 0.206 
  • R-Value Work: 0.180 
  • R-Value Observed: 0.181 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Structure of soybean serine acetyltransferase and formation of the cysteine regulatory complex as a molecular chaperone.

Yi, H.Dey, S.Kumaran, S.Lee, S.G.Krishnan, H.B.Jez, J.M.

(2013) J Biol Chem 288: 36463-36472

  • DOI: 10.1074/jbc.M113.527143
  • Primary Citation of Related Structures:  
    4N69, 4N6A, 4N6B

  • PubMed Abstract: 
  • Serine acetyltransferase (SAT) catalyzes the limiting reaction in plant and microbial biosynthesis of cysteine. In addition to its enzymatic function, SAT forms a macromolecular complex with O-acetylserine sulfhydrylase. Formation of the cysteine regulatory complex (CRC) is a critical biochemical control feature in plant sulfur metabolism ...

    Serine acetyltransferase (SAT) catalyzes the limiting reaction in plant and microbial biosynthesis of cysteine. In addition to its enzymatic function, SAT forms a macromolecular complex with O-acetylserine sulfhydrylase. Formation of the cysteine regulatory complex (CRC) is a critical biochemical control feature in plant sulfur metabolism. Here we present the 1.75-3.0 Å resolution x-ray crystal structures of soybean (Glycine max) SAT (GmSAT) in apoenzyme, serine-bound, and CoA-bound forms. The GmSAT-serine and GmSAT-CoA structures provide new details on substrate interactions in the active site. The crystal structures and analysis of site-directed mutants suggest that His(169) and Asp(154) form a catalytic dyad for general base catalysis and that His(189) may stabilize the oxyanion reaction intermediate. Glu(177) helps to position Arg(203) and His(204) and the β1c-β2c loop for serine binding. A similar role for ionic interactions formed by Lys(230) is required for CoA binding. The GmSAT structures also identify Arg(253) as important for the enhanced catalytic efficiency of SAT in the CRC and suggest that movement of the residue may stabilize CoA binding in the macromolecular complex. Differences in the effect of cold on GmSAT activity in the isolated enzyme versus the enzyme in the CRC were also observed. A role for CRC formation as a molecular chaperone to maintain SAT activity in response to an environmental stress is proposed for this multienzyme complex in plants.


    Organizational Affiliation

    From the Department of Biological Sciences, Chungnam National University, 220 Gung-Dong, Yuseong-Gu, Daejeon 305-764, Korea.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Serine Acetyltransferase ApoenzymeA, B286Glycine maxMutation(s): 0 
Gene Names: 100815091GLYMA_07G058800
EC: 2.3.1.30
Find proteins for I1KHY6 (Glycine max)
Explore I1KHY6 
Go to UniProtKB:  I1KHY6
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
PO4
Query on PO4

Download Ideal Coordinates CCD File 
C [auth B]PHOSPHATE ION
O4 P
NBIIXXVUZAFLBC-UHFFFAOYSA-K
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.75 Å
  • R-Value Free: 0.206 
  • R-Value Work: 0.180 
  • R-Value Observed: 0.181 
  • Space Group: H 3
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 110.868α = 90
b = 110.868β = 90
c = 144.011γ = 120
Software Package:
Software NamePurpose
HKL-3000data collection
PHASERphasing
PHENIXrefinement
HKL-3000data reduction
HKL-3000data scaling

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2013-11-13
    Type: Initial release
  • Version 1.1: 2013-12-11
    Changes: Database references
  • Version 1.2: 2014-01-08
    Changes: Database references