1HGX image
Deposition Date 1996-03-12
Release Date 1996-08-17
Last Version Date 2024-04-03
Entry Detail
PDB ID:
1HGX
Title:
HYPOXANTHINE-GUANINE-XANTHINE PHOSPHORIBOSYLTRANSFERASE (HGXPRTASE)
Biological Source:
Source Organism:
Host Organism:
Method Details:
Experimental Method:
Resolution:
1.90 Å
R-Value Free:
0.23
R-Value Work:
0.17
R-Value Observed:
0.17
Space Group:
P 1 21 1
Macromolecular Entities
Polymer Type:polypeptide(L)
Molecule:HYPOXANTHINE-GUANINE-XANTHINE PHOSPHORIBOSYLTRANSFERASE
Gene (Uniprot):HPT
Chain IDs:A, B
Chain Length:183
Number of Molecules:2
Biological Source:Tritrichomonas foetus
Primary Citation
Crystal structure of the hypoxanthine-guanine-xanthine phosphoribosyltransferase from the protozoan parasite Tritrichomonas foetus.
Biochemistry 35 7032 7040 (1996)
PMID: 8679528 DOI: 10.1021/bi953072p

Abstact

The crystal structure of the hypoxanthine-guanine-xanthine phosphoribosyltransferase (HGXPRTase) from Tritrichomonas foetus has been determined and refined against X-ray data to 1.9 A resolution. T. foetus HGXPRTase crystallizes as an asymmetric dimer, with GMP bound to only one of the two molecules that form the asymmetric unit. Each molecule of HGXPRTase is formed by two lobes joined by a short "hinge" region, and the GMP binds in a cavity between the two lobes. A comparison of the two molecules in the asymmetric unit shows that the hinge region is flexible and that ligand binding affects the relative positions of the two lobes. The binding of GMP brings the two lobes closer together, rotating one lobe by about 5 degrees relative to the other. T. foetus appears to depend on HGXPRTase for its supply of GMP, making this enzyme a target for antiparasite drug design. A comparison of the structures of T. foetus HGXPRTase and human HGPRTase reveals that, while these enzymes retain a similar polypeptide fold, there are substantial differences between the active sites of these two homologs. These differences suggest that it will be possible to find compounds that selectively inhibit the parasite enzyme.

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Primary Citation of related structures