4IS4

The glutamine synthetase from the dicotyledonous plant M. truncatula is a decamer


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.35 Å
  • R-Value Free: 0.217 
  • R-Value Work: 0.175 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

The structures of cytosolic and plastid-located glutamine synthetases from Medicago truncatula reveal a common and dynamic architecture.

Torreira, E.Seabra, A.R.Marriott, H.Zhou, M.Llorca, O.Robinson, C.V.Carvalho, H.G.Fernandez-Tornero, C.Pereira, P.J.

(2014) Acta Crystallogr.,Sect.D 70: 981-993

  • DOI: 10.1107/S1399004713034718

  • PubMed Abstract: 
  • The first step of nitrogen assimilation in higher plants, the energy-driven incorporation of ammonia into glutamate, is catalyzed by glutamine synthetase. This central process yields the readily metabolizable glutamine, which in turn is at the basis ...

    The first step of nitrogen assimilation in higher plants, the energy-driven incorporation of ammonia into glutamate, is catalyzed by glutamine synthetase. This central process yields the readily metabolizable glutamine, which in turn is at the basis of all subsequent biosynthesis of nitrogenous compounds. The essential role performed by glutamine synthetase makes it a prime target for herbicidal compounds, but also a suitable intervention point for the improvement of crop yields. Although the majority of crop plants are dicotyledonous, little is known about the structural organization of glutamine synthetase in these organisms and about the functional differences between the different isoforms. Here, the structural characterization of two glutamine synthetase isoforms from the model legume Medicago truncatula is reported: the crystallographic structure of cytoplasmic GSII-1a and an electron cryomicroscopy reconstruction of plastid-located GSII-2a. Together, these structural models unveil a decameric organization of dicotyledonous glutamine synthetase, with two pentameric rings weakly connected by inter-ring loops. Moreover, rearrangement of these dynamic loops changes the relative orientation of the rings, suggesting a zipper-like mechanism for their assembly into a decameric enzyme. Finally, the atomic structure of M. truncatula GSII-1a provides important insights into the structural determinants of herbicide resistance in this family of enzymes, opening new avenues for the development of herbicide-resistant plants.


    Related Citations: 
    • Crystallization and preliminary crystallographic characterization of glutamine synthetase from Medicago truncatula.
      Seabra, A.R.,Carvalho, H.,Pereira, P.J.
      (2009) Acta Crystallogr.,Sect.F 65: 1309


    Organizational Affiliation

    Chemical and Physical Biology, Centro de Investigaciones Biol├│gicas - CSIC, Ramiro de Maeztu 9, 28040 Madrid, Spain.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Glutamine synthetase
A, B, C, D, E, F, G, H, I, J
378Medicago truncatulaMutation(s): 0 
Gene Names: 11427840
EC: 6.3.1.2
Find proteins for O04998 (Medicago truncatula)
Go to UniProtKB:  O04998
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.35 Å
  • R-Value Free: 0.217 
  • R-Value Work: 0.175 
  • Space Group: P 1 21 1
  • Diffraction Data DOI: 
    10.15785/SBGRID/99 SBGrid
Unit Cell:
Length (Å)Angle (°)
a = 99.335α = 90.00
b = 101.672β = 103.69
c = 188.084γ = 90.00
Software Package:
Software NamePurpose
SCALAdata scaling
PHENIXrefinement
PHASERphasing
MOSFLMdata reduction
ADSCdata collection

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2014-04-09
    Type: Initial release
  • Version 1.1: 2014-09-24
    Type: Database references