3TF5

Structure of UDP-glucose dehydrogenase V132 deletion


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.3 Å
  • R-Value Free: 0.230 
  • R-Value Work: 0.201 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Conformational flexibility in the allosteric regulation of human UDP-{alpha}-D-glucose 6-dehydrogenase.

Sennett, N.C.Kadirvelraj, R.Wood, Z.A.

(2011) Biochemistry 50: 9651-9663

  • DOI: 10.1021/bi201381e

  • PubMed Abstract: 
  • UDP-α-D-xylose (UDX) acts as a feedback inhibitor of human UDP-α-D-glucose 6-dehydrogenase (hUGDH) by activating an unusual allosteric switch, the Thr131 loop. UDX binding induces the Thr131 loop to translate ~5 Å through the protein core, changing p ...

    UDP-α-D-xylose (UDX) acts as a feedback inhibitor of human UDP-α-D-glucose 6-dehydrogenase (hUGDH) by activating an unusual allosteric switch, the Thr131 loop. UDX binding induces the Thr131 loop to translate ~5 Å through the protein core, changing packing interactions and rotating a helix (α6(136-144)) to favor the formation of an inactive hexameric complex. But how does to conformational change occur given the steric packing constraints of the protein core? To answer this question, we deleted Val132 from the Thr131 loop to approximate an intermediate state in the allosteric transition. The 2.3 Å resolution crystal structure of the deletion construct (Δ132) reveals an open conformation that relaxes steric constraints and facilitates repacking of the protein core. Sedimentation velocity studies show that the open conformation stabilizes the Δ132 construct as a hexamer with point group symmetry 32, similar to that of the active complex. In contrast, the UDX-inhibited enzyme forms a lower-symmetry, horseshoe-shaped hexameric complex. We show that the Δ132 and UDX-inhibited structures have similar hexamer-building interfaces, suggesting that the hinge-bending motion represents a path for the allosteric transition between the different hexameric states. On the basis of (i) main chain flexibility and (ii) a model of the conformational change, we propose that hinge bending can occur as a concerted motion between adjacent subunits in the high-symmetry hexamer. We combine these results in a structurally detailed model for allosteric feedback inhibition and substrate--product exchange during the catalytic cycle.


    Organizational Affiliation

    Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia 30602, United States.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
UDP-glucose 6-dehydrogenase
A, B, C
493Homo sapiensMutation(s): 0 
Gene Names: UGDH
EC: 1.1.1.22
Find proteins for O60701 (Homo sapiens)
Go to Gene View: UGDH
Go to UniProtKB:  O60701
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.3 Å
  • R-Value Free: 0.230 
  • R-Value Work: 0.201 
  • Space Group: C 1 2 1
Unit Cell:
Length (Å)Angle (°)
a = 180.030α = 90.00
b = 116.930β = 115.93
c = 96.340γ = 90.00
Software Package:
Software NamePurpose
SERGUIdata collection
XDSdata scaling
PHASERphasing
PHENIXrefinement
XDSdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2011-10-12
    Type: Initial release
  • Version 1.1: 2012-01-11
    Type: Database references