4WYI

The crystal structure of Arabidopsis thaliana galactolipid synthase, MGD1 (apo-form)


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.50 Å
  • R-Value Free: 0.200 
  • R-Value Work: 0.181 
  • R-Value Observed: 0.181 

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Literature

Structural insights and membrane binding properties of MGD1, the major galactolipid synthase in plants.

Rocha, J.Sarkis, J.Thomas, A.Pitou, L.Radzimanowski, J.Audry, M.Chazalet, V.de Sanctis, D.Palcic, M.M.Block, M.A.Girard-Egrot, A.Marechal, E.Breton, C.

(2016) Plant J 85: 622-633

  • DOI: 10.1111/tpj.13129
  • Primary Citation of Related Structures:  
    4X1T, 4WYI

  • PubMed Abstract: 
  • Monogalactosyldiacylglycerol (MGDG) and digalactosyldiacylglycerol (DGDG) are the major lipid components of photosynthetic membranes, and hence the most abundant lipids in the biosphere. They are essential for assembly and function of the photosynthe ...

    Monogalactosyldiacylglycerol (MGDG) and digalactosyldiacylglycerol (DGDG) are the major lipid components of photosynthetic membranes, and hence the most abundant lipids in the biosphere. They are essential for assembly and function of the photosynthetic apparatus. In Arabidopsis, the first step of galactolipid synthesis is catalyzed by MGDG synthase 1 (MGD1), which transfers a galactosyl residue from UDP-galactose to diacylglycerol (DAG). MGD1 is a monotopic protein that is embedded in the inner envelope membrane of chloroplasts. Once produced, MGDG is transferred to the outer envelope membrane, where DGDG synthesis occurs, and to thylakoids. Here we present two crystal structures of MGD1: one unliganded and one complexed with UDP. MGD1 has a long and flexible region (approximately 50 amino acids) that is required for DAG binding. The structures reveal critical features of the MGD1 catalytic mechanism and its membrane binding mode, tested on biomimetic Langmuir monolayers, giving insights into chloroplast membrane biogenesis. The structural plasticity of MGD1, ensuring very rapid capture and utilization of DAG, and its interaction with anionic lipids, possibly driving the construction of lipoproteic clusters, are consistent with the role of this enzyme, not only in expansion of the inner envelope membrane, but also in supplying MGDG to the outer envelope and nascent thylakoid membranes.


    Organizational Affiliation

    Centre National de la Recherche Scientifique/Centre de Recherches sur les Macromolécules Végétales, 38041, Grenoble, France.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Monogalactosyldiacylglycerol synthase 1, chloroplasticA408Arabidopsis thalianaMutation(s): 0 
Gene Names: MGD1MGDAAt4g31780F28M20.30EMB2797
EC: 2.4.1.46
Find proteins for O81770 (Arabidopsis thaliana)
Explore O81770 
Go to UniProtKB:  O81770
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.50 Å
  • R-Value Free: 0.200 
  • R-Value Work: 0.181 
  • R-Value Observed: 0.181 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 59.61α = 90
b = 65.619β = 90
c = 80.401γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
XDSdata reduction
SCALAdata scaling
PHASERphasing

Structure Validation

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Entry History & Funding Information

Deposition Data

  • Deposited Date: 2014-11-17 
  • Released Date: 2016-02-17 
  • Deposition Author(s): Rocha, J., Breton, C.

Funding OrganizationLocationGrant Number
French National Research AgencyFrance--

Revision History 

  • Version 1.0: 2016-02-17
    Type: Initial release
  • Version 1.1: 2016-10-05
    Changes: Database references
  • Version 2.0: 2017-08-30
    Changes: Advisory, Atomic model, Author supporting evidence