2WJZ

Crystal structure of (HisH) K181A Y138A mutant of imidazoleglycerolphosphate synthase (HisH HisF) which displays constitutive glutaminase activity


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.60 Å
  • R-Value Free: 0.218 
  • R-Value Work: 0.185 
  • R-Value Observed: 0.187 

Starting Model: experimental
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wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Catalysis Uncoupling in a Glutamine Amidotransferase Bienzyme by Unblocking the Glutaminase Active Site.

List, F.Vega, M.C.Razeto, A.Hager, M.C.Sterner, R.Wilmanns, M.

(2012) Chem Biol 19: 1589

  • DOI: https://doi.org/10.1016/j.chembiol.2012.10.012
  • Primary Citation of Related Structures:  
    2WJZ, 3ZR4

  • PubMed Abstract: 

    Nitrogen is incorporated into various metabolites by multifunctional glutamine amidotransferases via reactive ammonia generated by glutaminase hydrolysis of glutamine. Although this process is generally tightly regulated by subsequent synthase activity, little is known about how the glutaminase is inhibited in the absence of an activating signal. Here, we use imidazoleglycerolphosphate synthase as a model to investigate the mechanism of glutaminase regulation. A structure of the bienzyme-glutamine complex reveals that the glutaminase active site is in a catalysis-competent conformation but the ammonia pathway toward the synthase active site is blocked. Mutation of two residues blocking the pathway leads to a complete uncoupling of the two reactions and to a 2800-fold amplification of glutaminase activity. Our data advance the understanding of coupling enzymatic activities in glutamine amidotransferases and raise hypotheses of the underlying molecular mechanism.


  • Organizational Affiliation

    EMBL Hamburg, Notkestrasse 85, Building 25A, D-22603 Hamburg, Germany.


Macromolecules
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Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
IMIDAZOLE GLYCEROL PHOSPHATE SYNTHASE HISF
A, C, E
253Thermotoga maritimaMutation(s): 0 
EC: 4.1.3
UniProt
Find proteins for Q9X0C6 (Thermotoga maritima (strain ATCC 43589 / DSM 3109 / JCM 10099 / NBRC 100826 / MSB8))
Explore Q9X0C6 
Go to UniProtKB:  Q9X0C6
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ9X0C6
Sequence Annotations
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  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 2
MoleculeChains Sequence LengthOrganismDetailsImage
IMIDAZOLE GLYCEROL PHOSPHATE SYNTHASE SUBUNIT HISH
B, D, F
201Thermotoga maritimaMutation(s): 2 
EC: 2.4.2
UniProt
Find proteins for Q9X0C8 (Thermotoga maritima (strain ATCC 43589 / DSM 3109 / JCM 10099 / NBRC 100826 / MSB8))
Explore Q9X0C8 
Go to UniProtKB:  Q9X0C8
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ9X0C8
Sequence Annotations
Expand
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.60 Å
  • R-Value Free: 0.218 
  • R-Value Work: 0.185 
  • R-Value Observed: 0.187 
  • Space Group: P 32
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 93.935α = 90
b = 93.935β = 90
c = 166.33γ = 120
Software Package:
Software NamePurpose
PHENIXrefinement
HKL-2000data reduction
SCALEPACKdata scaling
PHASERphasing

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2010-08-25
    Type: Initial release
  • Version 1.1: 2013-01-09
    Changes: Database references, Refinement description, Version format compliance
  • Version 1.2: 2023-12-13
    Changes: Data collection, Database references, Derived calculations, Other, Refinement description