Methanogen homoaconitase

Methanogen homoaconitase (, methanogen HACN) is an enzyme with systematic name (R)-2-hydroxybutane-1,2,4-tricarboxylate hydro-lyase ((1R,2S)-1-hydroxybutane-1,2,4-tricarboxylate-forming). This enzyme catalyses the following chemical reaction


 * (R)-2-hydroxybutane-1,2,4-tricarboxylate $$\rightleftharpoons$$ (1R,2S)-1-hydroxybutane-1,2,4-tricarboxylate (overall reaction)
 * (1a) (R)-2-hydroxybutane-1,2,4-tricarboxylate $$\rightleftharpoons$$ (Z)-but-1-ene-1,2,4-tricarboxylate + H2O
 * (1b) (Z)-but-1-ene-1,2,4-tricarboxylate + H2O $$\rightleftharpoons$$ (1R,2S)-1-hydroxybutane-1,2,4-tricarboxylate

This enzyme catalyses several reactions in the pathway of coenzyme-B biosynthesis in methanogenic archaea.