Biological Assembly 1  

Global Symmetry: Dihedral - D6  (3D View)
Global Stoichiometry: Homo 12-mer - A12 

Biological assembly 1 assigned by authors and generated by PISA (software)

Macromolecule Content

• Total Structure Weight: 623.83 kDa 
• Atom Count: 43,692 
• Modelled Residue Count: 5,616 
• Deposited Residue Count: 5,628 
• Unique protein chains: 1

 2GLS

REFINED ATOMIC MODEL OF GLUTAMINE SYNTHETASE AT 3.5 ANGSTROMS RESOLUTION

• PDB DOI:  https://doi.org/10.2210/pdb2GLS/pdb

• Classification: LIGASE(AMIDE SYNTHETASE)
• Organism(s): Salmonella enterica subsp. enterica serovar Typhimurium
• Mutation(s): No 


• Deposited: 1989-05-19 Released: 1989-10-15 
• Deposition Author(s): Eisenberg, D., Almassy, R.J., Yamashita, M.M.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 3.50 Å
• R-Value Observed: 0.258 

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: 2572586 
• DOI: https://doi.org/10.2210/pdb2gls/pdb
• Primary Citation of Related Structures:  
  2GLS


• 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 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."

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Related Citations: 

• 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

• 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

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Organizational Affiliation: 

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

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
GLUTAMINE SYNTHETASE	A, B, C, D, E, F, G, H, I, J, K, L	469	Salmonella enterica subsp. enterica serovar Typhimurium	Mutation(s): 0  EC: 6.3.1.2
UniProt
Find proteins for P0A1P6 (Salmonella typhimurium (strain LT2 / SGSC1412 / ATCC 700720)) Explore P0A1P6  Go to UniProtKB:  P0A1P6

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
MN	AA [auth H], BA [auth H], CA [auth I], DA [auth I], EA [auth J], FA [auth J], GA [auth K], HA [auth K], IA [auth L], JA [auth L], M [auth A], N [auth A], O [auth B], P [auth B], Q [auth C], R [auth C], S [auth D], T [auth D], U [auth E], V [auth E], W [auth F], X [auth F], Y [auth G], Z [auth G]	MANGANESE (II) ION Mn WAEMQWOKJMHJLA-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 3.50 Å
• R-Value Observed: 0.258 
• Space Group: C 1 2 1

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 235.5	α = 90
b = 134.5	β = 102.8
c = 200.1	γ = 90

Software Package:

Software Name	Purpose
PROLSQ	refinement

Structure Validation

Entry History 

Deposition Data

• Released Date: 1989-10-15 
Deposition Author(s): Eisenberg, D., Almassy, R.J., Yamashita, M.M.

Revision History  

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