|Gene:||ptmE||Accession Number: G-12602 (MetaCyc)|
The subunit structure of this enzyme has not been reported.
In the food-borne pathogen Campylobacter jejuni this enzyme participates in the biosynthesis of CMP-N,N'-diacetyllegionaminate (CMP-legionaminic acid), a virulence-associated, cell surface sialic acid-like derivative (see pathway CMP-legionaminate biosynthesis I). PtmE is a nucleotidyltransferase with an absolute specificity for GTP when D-glucosamine 1-phosphate is the substrate. This allowed large-scale purification of GDP-D-glucosamine) [Schoenhofen09].
Recombinant, N-terminal His6-tagged polypeptide was purified and characterized. The ptmE gene sequence contained a CBS domain of unknown function [Schoenhofen09].
In "one pot" enzymatic reactions, PtmF, PtmA, PgmL and PtmE converted β-D-fructofuranose 6-phosphate to GDP-D-glucosamine in the CMP-legionaminic acid biosynthetic pathway. Metabolites were purified and identified by capillary electrophoresis/mass spectrometry analysis and NMR spectroscopy [Schoenhofen09].
|Map Position: [1,256,292 -> 1,257,317]|
Molecular Weight of Polypeptide: 38.839 kD (from nucleotide sequence)
Enzymatic reaction of: glucosamine-1-phosphate guanylyltransferase
EC Number: 2.7.7.-
The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the direction in which it was curated.
The reaction is favored in the direction shown.
In Pathways: CMP-legionaminate biosynthesis I
This nucleotidyltransferase showed an absolute specificity for GTP as donor when D-glucosamine 1-phosphate was used as acceptor. The enzyme was specific for the C4 configuration of D-glucose. galactosamine-1-phosphate was not a substrate. When N-acetyl-α-D-glucosamine 1-phosphate was used as acceptor, the enzyme showed more promiscuity with regard to NTP donors [Schoenhofen09].
Schoenhofen09: Schoenhofen IC, Vinogradov E, Whitfield DM, Brisson JR, Logan SM (2009). "The CMP-legionaminic acid pathway in Campylobacter: biosynthesis involving novel GDP-linked precursors." Glycobiology 19(7);715-25. PMID: 19282391
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