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MetaCyc Enzyme: UDP-N-acetylglucosamine pyrophosphorylase

Gene: UAP Accession Number: G-10033 (MetaCyc)

Species: Giardia intestinalis

Summary:
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].

Locations: cytosol

Molecular Weight of Polypeptide: 48.288 kD (from nucleotide sequence), 50 kD (experimental) [Mok05 ]

Unification Links: Protein Model Portal:Q8MUP8 , UniProt:Q8MUP8

Relationship Links: Entrez-Nucleotide:PART-OF:AF515661 , InterPro:IN-FAMILY:IPR002618 , Panther:IN-FAMILY:PTHR11952 , Pfam:IN-FAMILY:PF01704

Gene-Reaction Schematic: ?

GO Terms:

Cellular Component: GO:0005829 - cytosol [Macechko92]

Credits:
Created 15-May-2007 by Fulcher CA , SRI International


Enzymatic reaction of: UDP-N-acetylglucosamine pyrophosphorylase

EC Number: 2.7.7.23

N-acetyl-α-D-glucosamine 1-phosphate + UTP + H+ <=> UDP-N-acetyl-α-D-glucosamine + diphosphate

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

Summary:
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].

Cofactors or Prosthetic Groups: Mg2+ [Mok05]

Kinetic Parameters:

Substrate
Km (μM)
Citations
N-acetyl-α-D-glucosamine 1-phosphate
300.0
[Mok05]
UTP
38.0
[Mok05]


References

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

Milewski06: Milewski S, Gabriel I, Olchowy J (2006). "Enzymes of UDP-GlcNAc biosynthesis in yeast." Yeast 23(1);1-14. PMID: 16408321

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


Report Errors or Provide Feedback
Please cite the following article in publications resulting from the use of MetaCyc: Caspi et al, Nucleic Acids Research 42:D459-D471 2014
Page generated by SRI International Pathway Tools version 18.5 on Tue Nov 25, 2014, BIOCYC13A.