1XRJ

Rapid structure determination of human uridine-cytidine kinase 2 using a conventional laboratory X-ray source and a single samarium derivative


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å
  • R-Value Free: 0.219 
  • R-Value Work: 0.195 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Structure of human uridine-cytidine kinase 2 determined by SIRAS using a rotating-anode X-ray generator and a single samarium derivative.

Appleby, T.C.Larson, G.Cheney, I.W.Walker, H.Wu, J.Z.Zhong, W.Hong, Z.Yao, N.

(2005) Acta Crystallogr.,Sect.D 61: 278-284

  • DOI: 10.1107/S0907444904032937

  • PubMed Abstract: 
  • Uridine-cytidine nucleoside kinase 2 (UCK2) is the rate-limiting enzyme in the pyrimidine-nucleotide salvage pathway. UCK2 catalyzes the phosphorylation of the natural ribonucleosides cytidine and uridine to cytidine 5'-monophosphate (CMP) and uridin ...

    Uridine-cytidine nucleoside kinase 2 (UCK2) is the rate-limiting enzyme in the pyrimidine-nucleotide salvage pathway. UCK2 catalyzes the phosphorylation of the natural ribonucleosides cytidine and uridine to cytidine 5'-monophosphate (CMP) and uridine 5'-monophosphate (UMP), respectively, and activates several important frontline antimetabolite drugs. The present contribution reports the rapid crystal structure determination of human UCK2 complexed with a magnesium ion and the reaction products adenosine 5'-diphosphate (ADP) and CMP. Diffraction data were collected on a copper rotating-anode X-ray generator from one native UCK2 crystal and a single samarium-derivative crystal. Utilizing the relatively high anomalous signal from the samarium derivative at the Cu Kalpha wavelength, the structure was determined by single isomorphous replacement and single anomalous signal (SIRAS) phasing techniques. Two of the four major samarium sites are located in the active sites of the two UCK2 molecules that form the asymmetric unit and appear to displace the magnesium ions present in the native crystals. The crystal structures of UCK2 alone and in complex with various ligands have recently been determined using traditional multiple isomorphous replacement (MIR) phasing techniques and data from three heavy-atom derivatives. The reported structures validate our independently determined structure. Of more than 1000 kinase crystal structure entries in the Protein Data Bank, less than 1% of them have been determined by SIRAS. For the published kinase crystal structures determined by SIRAS, all data were reportedly collected at various synchrotron-radiation facilities. This study demonstrates that diffraction data collected from a single samarium derivative using Cu Kalpha radiation provides sufficient phasing power to determine a novel macromolecular crystal structure.


    Organizational Affiliation

    Drug Discovery, Valeant Pharmaceuticals International, 3300 Hyland Avenue, Costa Mesa, CA 92626, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Uridine-cytidine kinase 2
A, B
261Homo sapiensMutation(s): 0 
Gene Names: UCK2 (UMPK)
EC: 2.7.1.48
Find proteins for Q9BZX2 (Homo sapiens)
Go to Gene View: UCK2
Go to UniProtKB:  Q9BZX2
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ADP
Query on ADP

Download SDF File 
Download CCD File 
A, B
ADENOSINE-5'-DIPHOSPHATE
C10 H15 N5 O10 P2
XTWYTFMLZFPYCI-KQYNXXCUSA-N
 Ligand Interaction
C5P
Query on C5P

Download SDF File 
Download CCD File 
A, B
CYTIDINE-5'-MONOPHOSPHATE
C9 H14 N3 O8 P
IERHLVCPSMICTF-XVFCMESISA-N
 Ligand Interaction
MG
Query on MG

Download SDF File 
Download CCD File 
A, B
MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å
  • R-Value Free: 0.219 
  • R-Value Work: 0.195 
  • Space Group: C 1 2 1
Unit Cell:
Length (Å)Angle (°)
a = 88.630α = 90.00
b = 109.320β = 94.96
c = 64.520γ = 90.00
Software Package:
Software NamePurpose
DENZOdata reduction
CNXrefinement
MLPHAREphasing
SCALEPACKdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2005-03-15
    Type: Initial release
  • Version 1.1: 2008-04-30
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Derived calculations, Version format compliance