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Your query returned 2 entries. Printable version
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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