3VP4

Crystal structure of human glutaminase in complex with inhibitor 4


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.45 Å
  • R-Value Free: 0.216 
  • R-Value Work: 0.198 

wwPDB Validation   3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

Structural basis for the allosteric inhibitory mechanism of human kidney-type glutaminase (KGA) and its regulation by Raf-Mek-Erk signaling in cancer cell metabolism.

Thangavelu, K.Pan, C.Q.Karlberg, T.Balaji, G.Uttamchandani, M.Suresh, V.Schuler, H.Low, B.C.Sivaraman, J.

(2012) Proc Natl Acad Sci U S A 109: 7705-7710

  • DOI: 10.1073/pnas.1116573109
  • Primary Citation of Related Structures:  
    3CZD, 3VOY, 3VOZ, 3VP0, 3VP1, 3VP2, 3VP3, 3VP4

  • PubMed Abstract: 
  • Besides thriving on altered glucose metabolism, cancer cells undergo glutaminolysis to meet their energy demands. As the first enzyme in catalyzing glutaminolysis, human kidney-type glutaminase isoform (KGA) is becoming an attractive target for small molecules such as BPTES [bis-2-(5 phenylacetamido-1, 2, 4-thiadiazol-2-yl) ethyl sulfide], although the regulatory mechanism of KGA remains unknown ...

    Besides thriving on altered glucose metabolism, cancer cells undergo glutaminolysis to meet their energy demands. As the first enzyme in catalyzing glutaminolysis, human kidney-type glutaminase isoform (KGA) is becoming an attractive target for small molecules such as BPTES [bis-2-(5 phenylacetamido-1, 2, 4-thiadiazol-2-yl) ethyl sulfide], although the regulatory mechanism of KGA remains unknown. On the basis of crystal structures, we reveal that BPTES binds to an allosteric pocket at the dimer interface of KGA, triggering a dramatic conformational change of the key loop (Glu312-Pro329) near the catalytic site and rendering it inactive. The binding mode of BPTES on the hydrophobic pocket explains its specificity to KGA. Interestingly, KGA activity in cells is stimulated by EGF, and KGA associates with all three kinase components of the Raf-1/Mek2/Erk signaling module. However, the enhanced activity is abrogated by kinase-dead, dominant negative mutants of Raf-1 (Raf-1-K375M) and Mek2 (Mek2-K101A), protein phosphatase PP2A, and Mek-inhibitor U0126, indicative of phosphorylation-dependent regulation. Furthermore, treating cells that coexpressed Mek2-K101A and KGA with suboptimal level of BPTES leads to synergistic inhibition on cell proliferation. Consequently, mutating the crucial hydrophobic residues at this key loop abrogates KGA activity and cell proliferation, despite the binding of constitutive active Mek2-S222/226D. These studies therefore offer insights into (i) allosteric inhibition of KGA by BPTES, revealing the dynamic nature of KGA's active and inhibitory sites, and (ii) cross-talk and regulation of KGA activities by EGF-mediated Raf-Mek-Erk signaling. These findings will help in the design of better inhibitors and strategies for the treatment of cancers addicted with glutamine metabolism.


    Organizational Affiliation

    Department of Biological Sciences, National University of Singapore, Singapore 117543.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Glutaminase kidney isoform, mitochondrial A316Homo sapiensMutation(s): 0 
Gene Names: GLSGLS1KIAA0838
EC: 3.5.1.2
Find proteins for O94925 (Homo sapiens)
Explore O94925 
Go to UniProtKB:  O94925
NIH Common Fund Data Resources
PHAROS:  O94925
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
BP9
Query on BP9

Download Ideal Coordinates CCD File 
A
5,5'-butane-1,4-diylbis(1,3,4-thiadiazol-2-amine)
C8 H12 N6 S2
FXLSMCSUYSZCFA-UHFFFAOYSA-N
 Ligand Interaction
External Ligand Annotations 
IDBinding Affinity (Sequence Identity %)
BP9IC50 :  18600   nM  PDBBind
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.45 Å
  • R-Value Free: 0.216 
  • R-Value Work: 0.198 
  • Space Group: I 41 2 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 139.555α = 90
b = 139.555β = 90
c = 156.866γ = 90
Software Package:
Software NamePurpose
ADSCdata collection
MOLREPphasing
CNSrefinement
HKL-2000data reduction
HKL-2000data scaling

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2012-06-13
    Type: Initial release
  • Version 1.1: 2012-06-27
    Changes: Structure summary