2GLS

REFINED ATOMIC MODEL OF GLUTAMINE SYNTHETASE AT 3.5 ANGSTROMS RESOLUTION


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.5 Å

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Refined atomic model of glutamine synthetase at 3.5 A resolution.

Yamashita, M.M.Almassy, R.J.Janson, C.A.Cascio, D.Eisenberg, D.

(1989) J.Biol.Chem. 264: 17681-17690


  • PubMed Abstract: 
  • An atomic model of 43,692 non-hydrogen atoms has been determined for the 12-subunit enzyme glutamine synthetase from Salmonella typhimurium, by methods of x-ray diffraction including restrained least-squares atomic refinement against 65,223 unique re ...

    An atomic model of 43,692 non-hydrogen atoms has been determined for the 12-subunit enzyme glutamine synthetase from Salmonella typhimurium, by methods of x-ray diffraction including restrained least-squares atomic refinement against 65,223 unique reflections. At 3.5 A resolution the crystallographic R-factor (on 2 sigma data) is 25.8%. As reported earlier for the unrefined structure, the 12 subunits are arranged in two layers of six; at the interface of pairs of subunits within each layer, cylindrical active sites are formed by six anti-parallel beta strands contributed by one subunit and two strands by the neighboring subunit. This interpretation of the electron density map has now been supported by comparison with glutamine synthetase from Escherichia coli by the Fourier difference method. Each active site cylinder holds two Mn2+ ions, with each ion having as ligands three protein side chains and two water molecules (one water shared by both metals), as well as a histidyl side chain just beyond liganding distance. The protein ligands to Mn2+ 469 are Glu-131, Glu-212, and Glu-220; those to Mn2+ 470 are Glu-129, His-269, and Glu-357. The two layers of subunits are held together largely by the apolar COOH terminus, a helical thong, which inserts into a hydrophobic pocket formed by two neighboring subunits on the opposite ring. Also between layers, there is a hydrogen-bonded beta sheet interaction, as there is between subunits within a ring, but hydrophobic interactions account for most of the intersubunit stability. The central loop, which extends into the central aqueous channel, is subject to attack by at least five enzymes and is discussed as an enzyme "passive site."


    Related Citations: 
    • Sequence of Glutamine Synthetase from Salmonella Typhimurium and Implications for the Protein Structure
      Janson, C.A.,Kayne, P.S.,Almassy, R.J.,Grunstein, M.,Eisenberg, D.
      (1986) Gene 46: 297
    • Novel Subunit-Subunit Interactions in the Structure of Glutamine Synthetase
      Almassy, R.J.,Janson, C.A.,Hamlin, R.,Xuong, N.-H.,Eisenberg, D.
      (1986) Nature 323: 304


    Organizational Affiliation

    Molecular Biology Institute, University of California, Los Angeles 90024.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
GLUTAMINE SYNTHETASE
A, B, C, D, E, F, G, H, I, J, K, L
469Salmonella typhimurium (strain LT2 / SGSC1412 / ATCC 700720)Mutation(s): 0 
Gene Names: glnA
EC: 6.3.1.2
Find proteins for P0A1P6 (Salmonella typhimurium (strain LT2 / SGSC1412 / ATCC 700720))
Go to UniProtKB:  P0A1P6
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
MN
Query on MN

Download SDF File 
Download CCD File 
A, B, C, D, E, F, G, H, I, J, K, L
MANGANESE (II) ION
Mn
WAEMQWOKJMHJLA-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.5 Å
  • Space Group: C 1 2 1
Unit Cell:
Length (Å)Angle (°)
a = 235.500α = 90.00
b = 134.500β = 102.80
c = 200.100γ = 90.00
Software Package:
Software NamePurpose
PROLSQrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 1989-10-15
    Type: Initial release
  • Version 1.1: 2008-03-03
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Advisory, Version format compliance