4LNN

B. subtilis glutamine synthetase structures reveal large active site conformational changes and basis for isoenzyme specific regulation: structure of apo form of GS


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.1 Å
  • R-Value Free: 0.267 
  • R-Value Work: 0.217 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Structures of the Bacillus subtilis Glutamine Synthetase Dodecamer Reveal Large Intersubunit Catalytic Conformational Changes Linked to a Unique Feedback Inhibition Mechanism.

Murray, D.S.Chinnam, N.Tonthat, N.K.Whitfill, T.Wray, L.V.Fisher, S.H.Schumacher, M.A.

(2013) J.Biol.Chem. 288: 35801-35811

  • DOI: 10.1074/jbc.M113.519496
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Glutamine synthetase (GS), which catalyzes the production of glutamine, plays essential roles in nitrogen metabolism. There are two main bacterial GS isoenzymes, GSI-α and GSI-β. GSI-α enzymes, which have not been structurally characterized, are uniq ...

    Glutamine synthetase (GS), which catalyzes the production of glutamine, plays essential roles in nitrogen metabolism. There are two main bacterial GS isoenzymes, GSI-α and GSI-β. GSI-α enzymes, which have not been structurally characterized, are uniquely feedback-inhibited by Gln. To gain insight into GSI-α function, we performed biochemical and cellular studies and obtained structures for all GSI-α catalytic and regulatory states. GSI-α forms a massive 600-kDa dodecameric machine. Unlike other characterized GS, the Bacillus subtilis enzyme undergoes dramatic intersubunit conformational alterations during formation of the transition state. Remarkably, these changes are required for active site construction. Feedback inhibition arises from a hydrogen bond network between Gln, the catalytic glutamate, and the GSI-α-specific residue, Arg(62), from an adjacent subunit. Notably, Arg(62) must be ejected for proper active site reorganization. Consistent with these findings, an R62A mutation abrogates Gln feedback inhibition but does not affect catalysis. Thus, these data reveal a heretofore unseen restructuring of an enzyme active site that is coupled with an isoenzyme-specific regulatory mechanism. This GSI-α-specific regulatory network could be exploited for inhibitor design against Gram-positive pathogens.


    Organizational Affiliation

    From the Department of Biochemistry and Molecular Biology, Oregon Health and Science University, Portland, Oregon 97239.




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
443Bacillus subtilis (strain 168)Mutation(s): 0 
Gene Names: glnA
EC: 6.3.1.2
Find proteins for P12425 (Bacillus subtilis (strain 168))
Go to UniProtKB:  P12425
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SO4
Query on SO4

Download SDF File 
Download CCD File 
D, E, F, H
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
MG
Query on MG

Download SDF File 
Download CCD File 
A, B, C, D, E, F, G, H, I, J, K, L
MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.1 Å
  • R-Value Free: 0.267 
  • R-Value Work: 0.217 
  • Space Group: P 1
Unit Cell:
Length (Å)Angle (°)
a = 109.990α = 119.80
b = 138.380β = 90.19
c = 138.740γ = 93.85
Software Package:
Software NamePurpose
ADSCdata collection
MOLREPphasing
MOSFLMdata reduction
SCALAdata scaling
CNSrefinement

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: 2014-01-15
    Type: Database references