Taxonomic group: bacteria / Firmicutes
(Phylum: Firmicutes)
Host organism: Homo sapiens
Associated disease: diarrhea [ICD11:
ME05.1 
, ICD11:
SA55 ];
infection due to Bacillus cereus [ICD11:
XN8PY ]
The structure was elucidated in this paperNCBI PubMed ID: 20529859Journal NLM ID: 2985121RPublisher: Baltimore, MD: American Society for Biochemistry and Molecular Biology
Correspondence: peled
ccrc.uga.edu
Institutions: Complex Carbohydrate Research Center, University of Georgia, Athens, GA, USA, USA
We have identified an operon and characterized the functions of two genes from the severe food-poisoning bacterium, Bacillus cereus subsp. cytotoxis NVH 391-98, that are involved in the synthesis of a unique UDP-sugar, UDP-2-acetamido-2-deoxyxylose (UDP-N-acetyl-xylosamine, UDP-XylNAc). UGlcNAcDH encodes a UDP-N-acetyl-glucosamine 6-dehydrogenase, converting UDP-N-acetylglucosamine (UDP-GlcNAc) to UDP-N-acetyl-glucosaminuronic acid (UDP-GlcNAcA). The second gene in the operon, UXNAcS, encodes a distinct decarboxylase not previously described in the literature, which catalyzes the formation of UDP-XylNAc from UDP-GlcNAcA in the presence of exogenous NAD(+). UXNAcS is specific and cannot utilize UDP-glucuronic acid and UDP-galacturonic acid as substrates. UXNAcS is active as a dimer with catalytic efficiency of 7 mM(-1) s(-1). The activity of UXNAcS is completely abolished by NADH but unaffected by UDP-xylose. A real-time NMR-based assay showed unambiguously the dual enzymatic conversions of UDP-GlcNAc to UDP-GlcNAcA and subsequently to UDP-XylNAc. From the analyses of all publicly available sequenced genomes, it appears that UXNAcS is restricted to pathogenic Bacillus species, including Bacillus anthracis and Bacillus thuringiensis. The identification of UXNAcS provides insight into the formation of UDP-XylNAc. Understanding the metabolic pathways involved in the utilization of this amino-sugar may allow the development of drugs to combat and eradicate the disease.
biosynthesis, gene, Gene Expression Regulation, Uridine Diphosphate Sugars, Bacillus cereus, Uridine diphosphate Xylose
Structure type: monomer
Location inside paper: p.24826, fig.1B, UDPXylNAc
Compound class: nucleoside diphosphate sugar
Methods: 1H NMR, NMR-2D, MALDI-TOF MS, NMR-1D, genetic methods, biochemical methods, HPLC
Enzymes that release or process the structure: UXNAcS (decarboxylase)
Biosynthesis and genetic data: kinetic data,genetic data
Synthetic data: enzymatic
Comments, role: UDPXylNAc obtained in the presence of UDPGlcNAcA, NAD+ and UXNAcS.
Related record ID(s): 25263
NCBI Taxonomy refs (TaxIDs): 1396
Show glycosyltransferases
NMR conditions: in D2O at 298 K
[as TSV]
13C NMR data:
Linkage Residue C1 C2 C3 C4 C5
5,0,0,2 Ac
5,0,0 aDXylpN 97.5 56.3 73.8 72.5 65.3
5,0 P
5 P
xXnucU
1H NMR data:
Linkage Residue H1 H2 H3 H4 H5
5,0,0,2 Ac - 2.064
5,0,0 aDXylpN 5.454 3.962 3.73 3.71 3.760-3.806
5,0 P
5 P
xXnucU
1H/13C HSQC data:
Linkage Residue C1/H1 C2/H2 C3/H3 C4/H4 C5/H5
5,0,0,2 Ac NMR TSV error 2: unequal length of 13C and 1H datasets
5,0,0 aDXylpN 97.5/5.454 56.3/3.962 73.8/3.73 72.5/3.71 65.3/3.760-3.806
5,0 P
5 P
xXnucU
1H NMR data:
| Linkage | Residue | H1 | H2 | H3 | H4 | H5 |
|---|
| 5,0,0,2 | Ac |
| 2.064 | |
| 5,0,0 | aDXylpN | 5.454 | 3.962 | 3.73 | 3.71 | 3.760
3.806 |
| 5,0 | P | |
| 5 | P | |
| | xXnucU | |
|
13C NMR data:
| Linkage | Residue | C1 | C2 | C3 | C4 | C5 |
|---|
| 5,0,0,2 | Ac | |
| 5,0,0 | aDXylpN | 97.5 | 56.3 | 73.8 | 72.5 | 65.3 |
| 5,0 | P | |
| 5 | P | |
| | xXnucU | |
|
There is only one chemically distinct structure:
Found 
report error