Structure of PDB 1dbr Chain B

Receptor sequence

>1dbrB (length=219) Species: 5811 (Toxoplasma gondii)

ASKPIEDYGKGKGRIEPMYIPDNTFYNADDFLVPPHCKPYIDKILLPGGL
VKDRVEKLAYDIHRTYFGEELHIICILKGSRGFFNLLIDYLATIQKYSGR
ESSVPPFFEHYVRLLTVLSDDLSIFRDKHVLIVEDIVDTGFTLTEFGERL
KAVGPKSMRIATLVEKRTDRSNSLKGDFVGFSIEDVWIVGCCYDFNEMFR
DFDHVAVLSDAARKKFEKV

3D structure

• PDB: 1dbr Crystal structures of Toxoplasma gondii HGXPRTase reveal the catalytic role of a long flexible loop.
• Chain: B
• Resolution: 2.4 Å

Enzymatic activity

• Catalytic site (original residue number in PDB): E146 D147 D150 W199 R212
• Catalytic site (residue number reindexed from 1): E134 D135 D138 W187 R200
• Enzyme Commision number: 2.4.2.22: xanthine phosphoribosyltransferase.
  2.4.2.8: hypoxanthine phosphoribosyltransferase.

Interaction with ligand

Site #	Ligand	Ligand chain	Binding residues on receptor (original residue number in PDB)	Binding residues on receptor (residue number reindexed from 1)	Binding affinity
BS01	MG	B	E146 D147	E134 D135

Gene Ontology

Molecular Function

• GO:0000166 nucleotide binding
• GO:0000287 magnesium ion binding
• GO:0000310 xanthine phosphoribosyltransferase activity
• GO:0004422 hypoxanthine phosphoribosyltransferase activity
• GO:0016757 glycosyltransferase activity
• GO:0046872 metal ion binding
• GO:0052657 guanine phosphoribosyltransferase activity

Biological Process

• GO:0006166 purine ribonucleoside salvage
• GO:0006178 guanine salvage
• GO:0032263 GMP salvage
• GO:0032264 IMP salvage
• GO:0032265 XMP salvage
• GO:0046100 hypoxanthine metabolic process

Cellular Component

• GO:0005737 cytoplasm
• GO:0005829 cytosol

External links

• PDB: RCSB:1dbr, PDBe:1dbr, PDBj:1dbr
• PDBsum: 1dbr
• PubMed: 8836106
• UniProt: Q26997|HGXR_TOXGO Hypoxanthine-guanine-xanthine phosphoribosyltransferase (Gene Name=HPRT)