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phosphonoacetaldehyde hydrolase This enzyme catalyzes the cleavage of the carbon phosphorous bond of a phosphonate. The mechanism depends on the substrate having a carbonyl one carbon away from the cleavage position. This enzyme is a member of the Haloacid Dehalogenase (HAD) superfamily of aspartate-nucleophile hydrolases (pfam00702), and contains a modified version of the conserved catalytic motifs of that superfamily: the first motif is usually DxDx(T/V), here it is DxAxT, and in the third motif the normal conserved lysine is instead an arginine. Additionally, the enzyme contains a unique conserved catalytic lysine (B. cereus pos. 53) which is involved in the binding and activation of the substrate through the formation of a Schiff base. The substrate of this enzyme is the product of 2-aminoethylphosphonate (AEP) transaminase, phosphonoacetaldehyde. This degradation pathway for AEP may be related to its toxic properties which are utilized by microorganisms as a chemical warfare agent. [Central intermediary metabolism, Other]
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