4N6B

Soybean Serine Acetyltransferase Complexed with CoA


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.005 Å
  • R-Value Free: 0.268 
  • R-Value Work: 0.214 

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:  

  • 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 reg ...

    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: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Serine Acetyltransferase Apoenzyme
A, B, C, D, E, F
286Glycine maxMutation(s): 0 
Gene Names: 100815091
Find proteins for I1KHY6 (Glycine max)
Go to UniProtKB:  I1KHY6
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
COA
Query on COA

Download SDF File 
Download CCD File 
A, C, D, E, F
COENZYME A
C21 H36 N7 O16 P3 S
RGJOEKWQDUBAIZ-IBOSZNHHSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.005 Å
  • R-Value Free: 0.268 
  • R-Value Work: 0.214 
  • Space Group: C 1 2 1
Unit Cell:
Length (Å)Angle (°)
a = 207.077α = 90.00
b = 99.181β = 117.23
c = 120.256γ = 90.00
Software Package:
Software NamePurpose
HKL-3000data collection
HKL-3000data reduction
PHENIXrefinement
PHASERphasing
HKL-3000data scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

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