|Gene:||UAP||Accession Number: G-10033 (MetaCyc)|
Species: Giardia intestinalis
The enzyme is a member of the nucleotide diphosphate sugar pyrophosphorylase family, subfamily UDP-sugar pyrophosphorylases. Reviewed in [Milewski06].
In Giardia intestinalis (previously known as Giardia lamblia) the enzyme is developmentally controlled, with a 20-fold increase during encystment (in [Mok05]).
There are conflicting data in the literature regarding the subunit structure and regulation of UDP-N-acetylglucosamine pyrophosphorylase from Giardia intestinalis (Giardia lamblia). Purified native enzyme from strain MR4 was reported to be a dimer that is constitutively expressed and allosterically regulated by glucosamine 6-phosphate, the first intermediate in the pathway [Bulik98, Bulik00]. However, later work with the recombinant his-tagged enzyme from strain Portland 1 expressed in Escherichia coli suggested that the enzyme is a monomer that is induced during encystment and is not allosterically regulated by this compound [Mok05, Mok05a]. The five enzymes of the pathway appear to be under transcriptional control during encystment [Lopez03].
The denatured molecular mass of the recombinant, his-tagged enzyme was estimated by SDS-PAGE [Mok05].
Molecular Weight of Polypeptide: 48.288 kD (from nucleotide sequence), 50 kD (experimental) [Mok05 ]
|Cellular Component:||GO:0005829 - cytosol [Macechko92]|
Enzymatic reaction of: UDP-N-acetylglucosamine pyrophosphorylase
EC Number: 18.104.22.168
The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the Enzyme Commission system.
The reaction is favored in the direction shown.
In Pathways: UDP-N-acetyl-D-galactosamine biosynthesis II
The enzyme catalyzes the formation of UDP-N-acetylglucosamine from N-acetylglucosamine-1-phosphate and UTP. Kinetic data given here are for the purified, recombinant, his-tagged enzyme from strain Portland 1 expressed in Escherichia coli [Mok05].
Bulik00: Bulik DA, van Ophem P, Manning JM, Shen Z, Newburg DS, Jarroll EL (2000). "UDP-N-acetylglucosamine pyrophosphorylase, a key enzyme in encysting Giardia, is allosterically regulated." J Biol Chem 275(19);14722-8. PMID: 10799561
Bulik98: Bulik DA, Lindmark DG, Jarroll EL (1998). "Purification and characterization of UDP-N-acetylglucosamine pyrophosphorylase from encysting Giardia." Mol Biochem Parasitol 95(1);135-9. PMID: 9763295
Lopez03: Lopez AB, Sener K, Jarroll EL, van Keulen H (2003). "Transcription regulation is demonstrated for five key enzymes in Giardia intestinalis cyst wall polysaccharide biosynthesis." Mol Biochem Parasitol 128(1);51-7. PMID: 12706796
Macechko92: Macechko PT, Steimle PA, Lindmark DG, Erlandsen SL, Jarroll EL (1992). "Galactosamine-synthesizing enzymes are induced when Giardia encyst." Mol Biochem Parasitol 56(2);301-9. PMID: 1484552
Mok05: Mok MT, Edwards MR (2005). "Kinetic and physical characterization of the inducible UDP-N-acetylglucosamine pyrophosphorylase from Giardia intestinalis." J Biol Chem 280(47);39363-72. PMID: 16169849
Mok05a: Mok MT, Tay E, Sekyere E, Glenn WK, Bagnara AS, Edwards MR (2005). "Giardia intestinalis: molecular characterization of UDP-N-acetylglucosamine pyrophosphorylase." Gene 357(1);73-82. PMID: 15951138
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