Requires Co2+ or Mn2+ for activity. The enzyme is also able to catalyse the aldol cleavage of 4-hydroxy-2-oxopentanoate and 4-hydroxy-2-oxohexanoate, and can use 2-oxobutanoate as carbonyl donor, with lower efficiency. In the reverse direction, is able to condense a range of aldehyde acceptors with pyruvate. The enzyme from the bacterium Escherichia coli produces a racemic mixture of (4R)- and (4S)-hydroxy-2-oxoheptanedioate .
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