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Your query returned 3 entries. Printable version
EC | 2.3.3.14 | ||||||
Accepted name: | homocitrate synthase | ||||||
Reaction: | acetyl-CoA + H2O + 2-oxoglutarate = (2R)-2-hydroxybutane-1,2,4-tricarboxylate + CoA | ||||||
For diagram of L-Lysine synthesis, click here | |||||||
Glossary: | (R)-homocitrate = (2R)-2-hydroxybutane-1,2,4-tricarboxylate | ||||||
Other name(s): | 2-hydroxybutane-1,2,4-tricarboxylate 2-oxoglutarate-lyase (CoA-acetylating); acetyl-coenzyme A:2-ketoglutarate C-acetyl transferase; homocitrate synthetase; HCS | ||||||
Systematic name: | acetyl-CoA:2-oxoglutarate C-acetyltransferase (thioester-hydrolysing, carboxymethyl-forming) | ||||||
Comments: | Belongs in the α-aminoadipate pathway of lysine synthesis, along with EC 4.2.1.36, homoaconitate hydratase. The enzyme also acts with oxaloacetate as substrate, but more slowly [2,3]. | ||||||
Links to other databases: | BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 9075-60-9 | ||||||
References: |
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EC | 4.2.1.36 | ||||||
Accepted name: | homoaconitate hydratase | ||||||
Reaction: | (1R,2S)-1-hydroxybutane-1,2,4-tricarboxylate = (Z)-but-1-ene-1,2,4-tricarboxylate + H2O | ||||||
For diagram of l-lysine synthesis, click here | |||||||
Glossary: | cis-homoaconitate = (Z)-but-1-ene-1,2,4-tricarboxylate (R)-homocitrate = (2R)-2-hydroxybutane-1,2,4-tricarboxylate homoisocitrate = (-)-threo-homoisocitrate = (1R,2S)-1-hydroxybutane-1,2,4-tricarboxylate |
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Other name(s): | homoaconitase; cis-homoaconitase; HACN; Lys4; LysF; 2-hydroxybutane-1,2,4-tricarboxylate hydro-lyase (incorrect) | ||||||
Systematic name: | (1R,2S)-1-hydroxybutane-1,2,4-tricarboxylate hydro-lyase [(Z)-but-1-ene-1,2,4-tricarboxylate-forming] | ||||||
Comments: | Requires a [4Fe-4S] cluster for activity. The enzyme from the hyperthermophilic eubacterium Thermus thermophilus can catalyse the reaction shown above but cannot catalyse the previously described reaction, i.e. formation of (R)-homocitrate by hydration of cis-homoaconitate. The enzyme responsible for the conversion of cis-homoaconitate into (R)-homocitrate in T. thermophilus is unknown at present but the reaction can be catalysed in vitro using aconitate hydratase from pig (EC 4.2.1.3) [2]. | ||||||
Links to other databases: | BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 9030-68-6 | ||||||
References: |
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EC | 4.2.1.114 | ||||||
Accepted name: | methanogen homoaconitase | ||||||
Reaction: | (R)-2-hydroxybutane-1,2,4-tricarboxylate = (1R,2S)-1-hydroxybutane-1,2,4-tricarboxylate (overall reaction) (1a) (R)-2-hydroxybutane-1,2,4-tricarboxylate = (Z)-but-1-ene-1,2,4-tricarboxylate + H2O (1b) (Z)-but-1-ene-1,2,4-tricarboxylate + H2O = (1R,2S)-1-hydroxybutane-1,2,4-tricarboxylate |
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For diagram of the 2-aminoadipate pathway of L-lysine synthesis, click here | |||||||
Glossary: | cis-homoaconitate = (Z)-but-1-ene-1,2,4-tricarboxylate (R)-homocitrate = (R)-2-hydroxybutane-1,2,4-tricarboxylate homoisocitrate = (–)-threo-homoisocitrate = (1R,2S)-1-hydroxybutane-1,2,4-tricarboxylate |
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Other name(s): | methanogen HACN | ||||||
Systematic name: | (R)-2-hydroxybutane-1,2,4-tricarboxylate hydro-lyase [(1R,2S)-1-hydroxybutane-1,2,4-tricarboxylate-forming] | ||||||
Comments: | This enzyme catalyses several reactions in the pathway of coenzyme-B biosynthesis in methanogenic archaea. Requires a [4Fe-4S] cluster for activity. In contrast to EC 4.2.1.36, homoaconitate hydratase, this enzyme can catalyse both the dehydration of (R)-homocitrate to form cis-homoaconitate and the subsequent hydration reaction that forms homoisocitrate. In addition to cis-homoaconitate, the enzyme can also catalyse the hydration of the physiological substrates dihomoaconitate and trihomoaconitate as well as the non-physiological substrate tetrahomoaconitate. cis-Aconitate and threo-DL-isocitrate cannot act as substrates, and (S)-homocitrate and trans-homoaconitate act as inhibitors of the enzyme. | ||||||
Links to other databases: | BRENDA, EXPASY, KEGG, MetaCyc, PDB | ||||||
References: |
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