Literature summary for 2.4.2.8 extracted from

Keough, D.T.; Brereton, I.M.; de Jersey, J.; Guddat, L.W.
The crystal structure of free human hypoxanthine-guanine phosphoribosyltransferase reveals extensive conformational plasticity throughout the catalytic cycle (2005), J. Mol. Biol., 351, 170-181.

Crystallization (Commentary)

Crystallization (Comment)	Organism
purified recombinant mutant C22A/C105A/C205A enzyme 1. free or 2. in complex with inactive purine base analogue 7-hydroxy [4,3d] pyrazolo pyrimidine and 5-phospho-alpha-D-ribose 1-diphosphate, or 3. complexed with IMP or GMP, or 4. complexed with transition state analogue immuncillinHP-Mg2+-diphosphate, hanging drop vapour diffusion method, 18 mg/ml protein in 0.05 M Tris-HCl, pH 7.4, 1 mM MgCl2, 1 mM DTT, mixing of 0.002 ml of both protein and reservoir solution, the latter containing 0.2 M ammonium acetate, 0.1 m sodium acetate, pH 4.6, 30% w/v PEG 4000, 17°C, 2-7 days, cryoprotection by 30% glycerol in reservoir solution, X-ray diffraction structure determination and analysis at 1.9 A resolution	Homo sapiens

Crystallization (Comment)

Organism

purified recombinant mutant C22A/C105A/C205A enzyme 1. free or 2. in complex with inactive purine base analogue 7-hydroxy [4,3d] pyrazolo pyrimidine and 5-phospho-alpha-D-ribose 1-diphosphate, or 3. complexed with IMP or GMP, or 4. complexed with transition state analogue immuncillinHP-Mg2+-diphosphate, hanging drop vapour diffusion method, 18 mg/ml protein in 0.05 M Tris-HCl, pH 7.4, 1 mM MgCl2, 1 mM DTT, mixing of 0.002 ml of both protein and reservoir solution, the latter containing 0.2 M ammonium acetate, 0.1 m sodium acetate, pH 4.6, 30% w/v PEG 4000, 17°C, 2-7 days, cryoprotection by 30% glycerol in reservoir solution, X-ray diffraction structure determination and analysis at 1.9 A resolution

Homo sapiens

Protein Variants

Protein Variants	Comment	Organism
C22A/C105A/C205A	site-directed mutagenesis, kinetic and physical properties are similar to the wild-type enzyme, but the mutant enzyme is more resistant to oxidation	Homo sapiens

Metals/Ions

Metals/Ions	Comment	Organism	Structure
Mg2+	required	Homo sapiens

Natural Substrates/ Products (Substrates)

Natural Substrates	Organism	Comment (Nat. Sub.)	Natural Products	Comment (Nat. Pro.)	Rev.	Reac.
guanine + 5-phospho-alpha-D-ribose 1-diphosphate	Homo sapiens	-	GMP + diphosphate	-	r
hypoxanthine + 5-phospho-alpha-D-ribose 1-diphosphate	Homo sapiens	-	IMP + diphosphate	-	r

Organism

Organism	UniProt	Comment	Textmining
Homo sapiens	-	-	-

Reaction

Reaction	Comment	Organism	Reaction ID
IMP + diphosphate = hypoxanthine + 5-phospho-alpha-D-ribose 1-diphosphate	sequential mechanism with 5-phospho-alpha-D-ribose 1-diphosphate binding first, active site helix comprising D137-D153 with key active site residues K68, D137, and K165, substrate binding sites and structures, overview	Homo sapiens	a

Source Tissue

Source Tissue	Comment	Organism	Textmining
erythrocyte	-	Homo sapiens	-

Substrates and Products (Substrate)

Substrates	Comment Substrates	Organism	Products	Comment (Products)	Rev.
guanine + 5-phospho-alpha-D-ribose 1-diphosphate	-	Homo sapiens	GMP + diphosphate	-	r
hypoxanthine + 5-phospho-alpha-D-ribose 1-diphosphate	-	Homo sapiens	IMP + diphosphate	-	r
additional information	substrate binding induces conformational changes required for catalysis	Homo sapiens	?	-	?

Subunits

Subunits	Comment	Organism
tetramer	-	Homo sapiens

Synonyms

Synonyms	Comment	Organism
HGPRT	-	Homo sapiens
hypoxanthine-guanine phosphoribosyltransferase	-	Homo sapiens