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: 2.601 Å
  • R-Value Free: 0.218 
  • R-Value Work: 0.185 

wwPDB Validation 3D Report Full Report


This is version 1.1 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: 10.1016/j.chembiol.2012.10.012
  • Primary Citation of Related Structures:  

  • 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 activi ...

    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

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
IMIDAZOLE GLYCEROL PHOSPHATE SYNTHASE HISF
A, C, E
253Thermotoga maritima (strain ATCC 43589 / MSB8 / DSM 3109 / JCM 10099)Mutation(s): 0 
Gene Names: hisF
EC: 4.3.2.10
Find proteins for Q9X0C6 (Thermotoga maritima (strain ATCC 43589 / MSB8 / DSM 3109 / JCM 10099))
Go to UniProtKB:  Q9X0C6
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
IMIDAZOLE GLYCEROL PHOSPHATE SYNTHASE SUBUNIT HISH
B, D, F
201Thermotoga maritima (strain ATCC 43589 / MSB8 / DSM 3109 / JCM 10099)Mutation(s): 2 
Gene Names: hisH
EC: 4.3.2.10
Find proteins for Q9X0C8 (Thermotoga maritima (strain ATCC 43589 / MSB8 / DSM 3109 / JCM 10099))
Go to UniProtKB:  Q9X0C8
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
PO4
Query on PO4

Download SDF File 
Download CCD File 
A, C, E
PHOSPHATE ION
O4 P
NBIIXXVUZAFLBC-UHFFFAOYSA-K
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.601 Å
  • R-Value Free: 0.218 
  • R-Value Work: 0.185 
  • Space Group: P 32
Unit Cell:
Length (Å)Angle (°)
a = 93.935α = 90.00
b = 93.935β = 90.00
c = 166.330γ = 120.00
Software Package:
Software NamePurpose
PHENIXrefinement
HKL-2000data reduction
PHASERphasing
SCALEPACKdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2010-08-25
    Type: Initial release
  • Version 1.1: 2013-01-09
    Type: Database references, Refinement description, Version format compliance