1Z7G

Free human HGPRT


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.90 Å
  • R-Value Free: 0.254 
  • R-Value Work: 0.213 
  • R-Value Observed: 0.219 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

The Crystal Structure of Free Human Hypoxanthine-guanine Phosphoribosyltransferase Reveals Extensive Conformational Plasticity Throughout the Catalytic Cycle

Keough, D.T.Brereton, I.M.de Jersey, J.Guddat, L.W.

(2005) J Mol Biol 351: 170-181

  • DOI: 10.1016/j.jmb.2005.05.061
  • Primary Citation of Related Structures:  
    1Z7G

  • PubMed Abstract: 
  • Human hypoxanthine-guanine phosphoribosyltransferase (HGPRT) catalyses the synthesis of the purine nucleoside monophosphates, IMP and GMP, by the addition of a 6-oxopurine base, either hypoxanthine or guanine, to the 1-beta-position of 5-phospho-alpha-d-ribosyl-1-pyrophosphate (PRib-PP) ...

    Human hypoxanthine-guanine phosphoribosyltransferase (HGPRT) catalyses the synthesis of the purine nucleoside monophosphates, IMP and GMP, by the addition of a 6-oxopurine base, either hypoxanthine or guanine, to the 1-beta-position of 5-phospho-alpha-d-ribosyl-1-pyrophosphate (PRib-PP). The mechanism is sequential, with PRib-PP binding to the free enzyme prior to the base. After the covalent reaction, pyrophosphate is released followed by the nucleoside monophosphate. A number of snapshots of the structure of this enzyme along the reaction pathway have been captured. These include the structure in the presence of the inactive purine base analogue, 7-hydroxy [4,3-d] pyrazolo pyrimidine (HPP) and PRib-PP.Mg2+, and in complex with IMP or GMP. The third structure is that of the immucillinHP.Mg(2+).PP(i) complex, a transition-state analogue. Here, the first crystal structure of free human HGPRT is reported to 1.9A resolution, showing that significant conformational changes have to occur for the substrate(s) to bind and for catalysis to proceed. Included in these changes are relative movement of subunits within the tetramer, rotation and extension of an active-site alpha-helix (D137-D153), reorientation of key active-site residues K68, D137 and K165, and the rearrangement of three active-site loops (100-128, 165-173 and 186-196). Toxoplasma gondii HGXPRT is the only other 6-oxopurine phosphoribosyltransferase structure solved in the absence of ligands. Comparison of this structure with human HGPRT reveals significant differences in the two active sites, including the structure of the flexible loop containing K68 (human) or K79 (T.gondii).


    Organizational Affiliation

    School of Molecular and Microbial Sciences, University of Queensland, Brisbane 4072, Australia.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Hypoxanthine-guanine phosphoribosyltransferaseA, B, C, D217Homo sapiensMutation(s): 0 
Gene Names: HPRT1HPRT
EC: 2.4.2.8
UniProt & NIH Common Fund Data Resources
Find proteins for P00492 (Homo sapiens)
Explore P00492 
Go to UniProtKB:  P00492
PHAROS:  P00492
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.90 Å
  • R-Value Free: 0.254 
  • R-Value Work: 0.213 
  • R-Value Observed: 0.219 
  • Space Group: C 1 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 149.57α = 90
b = 51.8β = 105.8
c = 117.52γ = 90
Software Package:
Software NamePurpose
CRYSTALdata collection
CRYSTALdata reduction
CNSrefinement
CrystalCleardata reduction
CrystalCleardata scaling
CNSphasing

Structure Validation

View Full Validation Report




Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2005-08-02
    Type: Initial release
  • Version 1.1: 2008-04-30
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance