Metabolic Modeling Tutorial
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Metabolic Modeling Tutorial
discounted EARLY registration ends Dec 31, 2014
Metabolic Modeling Tutorial
discounted EARLY registration ends Dec 31, 2014
Metabolic Modeling Tutorial
discounted EARLY registration ends Dec 31, 2014
Metabolic Modeling Tutorial
discounted EARLY registration ends Dec 31, 2014
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MetaCyc Enzyme: glucosamine-6-phosphate acetyltransferase

Gene: GNA1 Accession Number: AT5G15770 (MetaCyc)

Species: Arabidopsis thaliana col

Subunit composition of glucosamine-6-phosphate acetyltransferase = [GNA1]2
         glucosamine 6-phosphate N-acetyltransferase = GNA1

Summary:
GNA1 is a glucosamine-6-phosphate (GlcN6P) N-acetyltransferase that contributes to the synthesis of UDP-N-acetyl-α-D-glucosamine based on in vitro assays [Riegler12]. Expression of a GNA1:GFP fusion protein suggests that the protein is localized to the endoplasmic reticulum where it likely plays a role in protein glycosylation and GPI anchor biosynthesis. Like GNAs found in other species, the Arabidopsis protein appears to exist as a dimer [Riegler12]. Unlike the case for many Arabidopsis genes, there is no obvious close paralog encoding this important enzyme present in the genome. Therefore, it is unsurprising that GNA1 transcripts can be detected in many different Arabidopsis organs including siliques, flowers, stems, leaves, and roots [Riegler12].

Locations: endoplasmic reticulum

Map Position: [5,144,096 -> 5,144,545]

Molecular Weight of Multimer: 40.35 kD (experimental) [Riegler12]

Unification Links: Phytozome Plant Orthologs:AT5G15770.1 , TAIR:AT5G15770 , UniProt:Q9LFU9

Gene-Reaction Schematic: ?

GO Terms:

Cellular Component: GO:0005783 - endoplasmic reticulum Inferred from experiment [Riegler12]


Enzymatic reaction of: glucosamine-6-phosphate acetyltransferase

EC Number: 2.3.1.4

D-glucosamine 6-phosphate + acetyl-CoA <=> N-acetyl-D-glucosamine 6-phosphate + coenzyme A + H+

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-glucosamine biosynthesis II

Summary:
The Kcat/ Km for for this enzyme for D-glucosamine 6-phosphate and acetyl-CoA are 0.523 and 0.55 s-1 μM-1 [Riegler12].

Kinetic Parameters:

Substrate
Km (μM)
kcat (sec-1)
kcat/Km (sec-1 μM-1)
Citations
D-glucosamine 6-phosphate
231.0
19.0
[Riegler12]
acetyl-CoA
33.0
[Riegler12]

T(opt): 35 °C [Riegler12]

pH(opt): 7-8 [Riegler12]


References

Jiang05: Jiang H, Dang L, Wang S, Chen H, Wu Y, Jiang X, Wu P (2005). "A novel short-root gene encodes a glucosamine-6-phosphate acetyltransferase required for maintaining normal root cell shape in rice." Plant Physiol 138(1);232-42. PMID: 15849305

Riegler12: Riegler H, Herter T, Grishkovskaya I, Lude A, Ryngajllo M, Bolger ME, Essigmann B, Usadel B (2012). "Crystal structure and functional characterization of a glucosamine-6-phosphate N-acetyltransferase from Arabidopsis thaliana." Biochem J. PMID: 22329777


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 Fri Dec 19, 2014, biocyc14.