Pathway · 2 proteins
Pyruvate metabolism
Proteins of this group that KEGG places on its “Pyruvate metabolism” map for Aquifex aeolicus.
How it works
This map covers the reactions around pyruvate, the hub between sugars, amino acids and the carbon-fixing cycle. The proteins here include the alpha chain of oxaloacetate decarboxylase, a membrane enzyme that removes carbon dioxide from oxaloacetate and uses the energy to move sodium ions.
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 |
|---|---|---|---|---|---|
| Oxaloacetate decarboxylase alpha chain | — | — | — | 620 | Step named |
| Uncharacterized protein aq_2135 | 3.-.-.- | — | Zn(2+) | 211 | Step named |
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 |
|---|---|---|---|---|---|
| Ferredoxin oxidoreductase alpha subunitHome: Sugar-phosphate supply | — | — | — | 389 | Step named |
| Ferredoxin oxidoreductase beta subunitHome: Glycolysis / Gluconeogenesis | — | — | — | 289 | Step named |
| Ferredoxin oxidoreductase gamma subunitHome: Pyruvate and acetyl-CoA | — | — | — | 230 | Step named |
| Ferredoxin oxidoreductase alpha subunitHome: Sugar-phosphate supply | — | — | — | 404 | Step named |
| Ferredoxin oxidoreductase beta subunitHome: Glycolysis / Gluconeogenesis | — | — | — | 286 | Step named |
| Ferredoxin oxidoreductase gamma subunitHome: Pyruvate and acetyl-CoA | — | — | — | 241 | Step named |
| C-terminal fumarate hydratase, class IHome: Not yet placed in a pathway | — | — | — | 185 | Step named |
| Fumarate hydratase (Fumarase)Home: Reductive TCA machinery | — | — | — | 281 | Step named |
| Malate dehydrogenase 1Home: Reductive TCA machinery | 1.1.1.37 | (S)-malate + NAD(+) = oxaloacetate + NADH + H(+) | — | 335 | Step named |
| Phosphoenolpyruvate synthaseHome: Pyruvate and acetyl-CoA | 2.7.9.2 | pyruvate + ATP + H2O = phosphoenolpyruvate + AMP + phosphate + 2 H(+) | Mg(2+) | 856 | Step named |
| 2-isopropylmalate synthaseHome: Branched-chain amino acids | 2.3.3.13 | 3-methyl-2-oxobutanoate + acetyl-CoA + H2O = (2S)-2-isopropylmalate + CoA + H(+) | Mn(2+) | 520 | Step named |
| (R)-citramalate synthaseHome: Branched-chain amino acids | 2.3.3.21 | pyruvate + acetyl-CoA + H2O = (3R)-citramalate + CoA + H(+) | — | 528 | Step named |
| Acetyl-coenzyme A carboxylase carboxyl transferase subunit alphaHome: Lipid and cofactor connections | 2.1.3.15 | N(6)-carboxybiotinyl-L-lysyl-[protein] + acetyl-CoA = N(6)-biotinyl-L-lysyl-[protein] + malonyl-CoA | — | 323 | Step named |
| Biotin carboxyl carrier protein of acetyl-CoA carboxylaseHome: Lipid and cofactor connections | — | — | — | 154 | Step named |
| Biotin carboxylaseHome: Lipid and cofactor connections | — | — | — | 477 | Step named |
| Biotin carboxylaseHome: Lipid and cofactor connections | 6.3.4.14 | N(6)-biotinyl-L-lysyl-[protein] + hydrogencarbonate + ATP = N(6)-carboxybiotinyl-L-lysyl-[protein] + ADP + phosphate + H(+) | — | 444 | Step named |
| Acetyl-coenzyme A carboxylase carboxyl transferase subunit betaHome: Lipid and cofactor connections | 2.1.3.15 | N(6)-carboxybiotinyl-L-lysyl-[protein] + acetyl-CoA = N(6)-biotinyl-L-lysyl-[protein] + malonyl-CoA | Zn(2+) | 276 | Step named |
| Dihydrolipoyl dehydrogenaseHome: Glycine, serine and threonine metabolism | 1.8.1.4 | N(6)-[(R)-dihydrolipoyl]-L-lysyl-[protein] + NAD(+) = N(6)-[(R)-lipoyl]-L-lysyl-[protein] + NADH + H(+) | — | 465 | Step named |
| Propionate--CoA ligaseHome: Glyoxylate and dicarboxylate metabolism | — | acetate + ATP + CoA = acetyl-CoA + AMP + diphosphate | — | 510 | Unspecified |
| D-lactate dehydrogenaseHome: Not yet placed in a pathway | — | — | — | 334 | Unspecified |
Origins
Could pyruvate, a hub of carbon metabolism, have formed and been used before enzymes?
Metabolism-first proposals have carbon monoxide and carbon dioxide turned into compounds such as pyruvate on mineral surfaces at high temperature and pressure, as at hydrothermal vents.
No proposed metabolic scheme has been shown to sustain itself, and it remains to be shown that the laboratory conditions are geologically plausible.
In the cell, pyruvate is converted by enzymes that need cofactors such as thiamine pyrophosphate, lipoate and coenzyme A, each with its own pathway.
From the books: Ribas de Pouplana (ed.), The Genetic Code and the Origin of Life, p. 11; Deamer, Assembling Life, p. 93.
The wider question for this part of the cell: origins for manufacturing cofactors and vitamins.
Sources
- KEGG map aae00620 (enzymes of this organism highlighted)
Other pathways in this group: Heme and quinones · Biotin and lipoate · NAD and flavins · Thiamine and pyridoxal · Folate and pterin chemistry · Lipid and cofactor connections · Coenzyme A · Aspartate-family branches · Amino-acid connections · Folate-linked carbon transfer · Serine, glycine and sulfur · Folate biosynthesis · Oxidative phosphorylation · Thiamine metabolism · Pantothenate and CoA biosynthesis · Glycine, serine and threonine metabolism · Riboflavin metabolism · Nicotinate and nicotinamide metabolism · Biotin metabolism · Cysteine and methionine metabolism · Porphyrin metabolism · Not yet placed in a pathway