3P0E

Structure of hUPP2 in an active conformation with bound 5-benzylacyclouridine


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.00 Å
  • R-Value Free: 0.242 
  • R-Value Work: 0.205 
  • R-Value Observed: 0.207 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

A novel structural mechanism for redox regulation of uridine phosphorylase 2 activity.

Roosild, T.P.Castronovo, S.Villoso, A.Ziemba, A.Pizzorno, G.

(2011) J Struct Biol 176: 229-237

  • DOI: 10.1016/j.jsb.2011.08.002
  • Structures With Same Primary Citation

  • PubMed Abstract: 
  • Uridine phosphorylase (UPP) catalyzes the reversible conversion of uridine to uracil and ribose-1-phosphate and plays an important pharmacological role in activating fluoropyrimidine nucleoside chemotherapeutic agents such as 5-fluorouracil and capec ...

    Uridine phosphorylase (UPP) catalyzes the reversible conversion of uridine to uracil and ribose-1-phosphate and plays an important pharmacological role in activating fluoropyrimidine nucleoside chemotherapeutic agents such as 5-fluorouracil and capecitabine. Most vertebrate animals, including humans, possess two homologs of this enzyme (UPP1 & UPP2), of which UPP1 has been more thoroughly studied and is better characterized. Here, we report two crystallographic structures of human UPP2 (hUPP2) in distinctly active and inactive conformations. These structures reveal that a conditional intramolecular disulfide bridge can form within the protein that dislocates a critical phosphate-coordinating arginine residue (R100) away from the active site, disabling the enzyme. In vitro activity measurements on both recombinant hUPP2 and native mouse UPP2 confirm the redox sensitivity of this enzyme, in contrast to UPP1. Sequence analysis shows that this feature is conserved among UPP2 homologs and lacking in all UPP1 proteins due to the absence of a necessary cysteine residue. The state of the disulfide bridge has further structural consequences for one face of the enzyme that suggest UPP2 may have additional functions in sensing and initiating cellular responses to oxidative stress. The molecular details surrounding these dynamic aspects of hUPP2 structure and regulation provide new insights as to how novel inhibitors of this protein may be developed with improved specificity and affinity. As uridine is emerging as a promising protective compound in neuro-degenerative diseases, including Alzheimer's and Parkinson's, understanding the regulatory mechanisms underlying UPP control of uridine concentration is key to improving clinical outcomes in these illnesses.


    Organizational Affiliation

    Department of Drug Development, Nevada Cancer Institute, One Breakthrough Way, Las Vegas, NV 89135, USA. troosild@nvcancer.org



Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Uridine phosphorylase 2
A, B, C, D, E, F
297Homo sapiensMutation(s): 0 
Gene Names: UPP2
EC: 2.4.2.3
Find proteins for O95045 (Homo sapiens)
Go to UniProtKB:  O95045
NIH Common Fund Data Resources
PHAROS  O95045
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
BAU
Query on BAU

Download CCD File 
A, B, C, D, E, F
1-((2-HYDROXYETHOXY)METHYL)-5-BENZYLPYRIMIDINE-2,4(1H,3H)-DIONE
C14 H16 N2 O4
SPJAGILXQBHHSZ-UHFFFAOYSA-N
 Ligand Interaction
PO4
Query on PO4

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

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.00 Å
  • R-Value Free: 0.242 
  • R-Value Work: 0.205 
  • R-Value Observed: 0.207 
  • Space Group: C 1 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 275.342α = 90
b = 56.137β = 96.38
c = 141.389γ = 90
Software Package:
Software NamePurpose
SCALEPACKdata scaling
MOLREPphasing
REFMACrefinement
PDB_EXTRACTdata extraction
ADSCdata collection
DENZOdata reduction

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2011-09-07
    Type: Initial release
  • Version 1.1: 2011-10-19
    Changes: Database references
  • Version 1.2: 2017-11-08
    Changes: Refinement description