Pathway · 7 proteins
Biosynthesis of various nucleotide sugars
Proteins of this group that KEGG places on its “Biosynthesis of various nucleotide sugars” map for Aquifex aeolicus.
How it works
This map covers activated sugars used on the cell surface. The proteins here make KDO and ADP-heptose, the sugars of the inner core of lipopolysaccharide, and GDP-linked sugars derived from mannose.
Grouped by KEGG pathway map. The explanation above is the atlas’s own; the map itself covers more organisms than Aquifex.
Its proteins
| Protein | EC | Reaction (UniProt) | Metal or cluster | Amino acids | Certainty |
|---|---|---|---|---|---|
| GDP-mannose 4,6-dehydratase | 4.2.1.47 | GDP-alpha-D-mannose = GDP-4-dehydro-alpha-D-rhamnose + H2O | — | 345 | Unspecified |
| Uncharacterized phosphosugar isomerase aq_1546 | — | — | — | 322 | Unspecified |
| D-glycero-beta-D-manno-heptose 1-phosphate adenylyltransferase | 2.7.7.70 | D-glycero-beta-D-manno-heptose 1-phosphate + ATP + H(+) = ADP-D-glycero-beta-D-manno-heptose + diphosphate | — | 157 | Unspecified |
| 3-deoxy-D-manno-octulosonate 8-phosphate phosphatase | — | — | Mg(2+) | 163 | Unspecified |
| ADP-L-glycero-D-manno-heptose-6-epimerase | — | — | — | 310 | Unspecified |
| ADP-heptose synthase | — | — | — | 315 | Unspecified |
| Phosphoheptose isomerase | 5.3.1.28 | 2 D-sedoheptulose 7-phosphate = D-glycero-alpha-D-manno-heptose 7-phosphate + D-glycero-beta-D-manno-heptose 7-phosphate | Zn(2+) | 191 | Unspecified |
Also part of this pathway
These proteins are described under another pathway, but also take part here.
| Protein | EC | Reaction (UniProt) | Metal or cluster | Amino acids | Certainty |
|---|---|---|---|---|---|
| UDP-glucose 6-dehydrogenaseHome: Amino sugar and nucleotide sugar metabolism | 1.1.1.22 | UDP-alpha-D-glucose + 2 NAD(+) + H2O = UDP-alpha-D-glucuronate + 2 NADH + 3 H(+) | — | 437 | Step named |
| UTP--glucose-1-phosphate uridylyltransferaseHome: Amino sugar and nucleotide sugar metabolism | 2.7.7.9 | alpha-D-glucose 1-phosphate + UTP + H(+) = UDP-alpha-D-glucose + diphosphate | — | 297 | Step named |
| mannose-1-phosphate guanylyltransferaseHome: Amino sugar and nucleotide sugar metabolism | 2.7.7.13 | alpha-D-mannose 1-phosphate + GTP + H(+) = GDP-alpha-D-mannose + diphosphate | — | 453 | Step named |
| Mannose-1-phosphate guanyltransferaseHome: Amino sugar and nucleotide sugar metabolism | — | — | — | 831 | Step named |
| 2-dehydro-3-deoxyphosphooctonate aldolaseHome: Biosynthesis of various nucleotide sugars | 2.5.1.55 | D-arabinose 5-phosphate + phosphoenolpyruvate + H2O = 3-deoxy-alpha-D-manno-2-octulosonate-8-phosphate + phosphate | — | 267 | Step named |
| 3-deoxy-manno-octulosonate cytidylyltransferaseHome: Biosynthesis of various nucleotide sugars | 2.7.7.38 | 3-deoxy-alpha-D-manno-oct-2-ulosonate + CTP = CMP-3-deoxy-beta-D-manno-octulosonate + diphosphate | — | 234 | Step named |
| Bifunctional protein GlmUHome: Not yet placed in a pathway | 2.3.1.157; 2.7.7.23 | alpha-D-glucosamine 1-phosphate + acetyl-CoA = N-acetyl-alpha-D-glucosamine 1-phosphate + CoA + H(+) | Mg(2+) | 464 | Step named |
Origins
How could the activated sugars used to build the cell surface have been made before these enzymes?
None of the books searched discusses a prebiotic route to nucleotide-activated sugars.
The cell builds surface sugars only from sugars activated on a nucleotide carrier, so making them depends on nucleotide supply as well as on sugar supply.
The wider question for this part of the cell: origins for conserved, but we cannot say what they do.
Sources
- KEGG map aae00541 (enzymes of this organism highlighted)
Other pathways in this group: tRNA charging · Nutrient and metabolic state · Purine metabolism · Bacterial secretion system · Glyoxylate and dicarboxylate metabolism · Starch and sucrose metabolism · Homologous recombination · Fructose and mannose metabolism · Streptomycin biosynthesis · Other carbon fixation pathways · Nicotinate and nicotinamide metabolism · Not yet placed in a pathway