is unique because it catalyzes the cleavage of the remarkably stable carbon–fluorine bond of a fluorinated aliphatic compound. in the reaction of l-2-haloacid dehalogenase and fluoroacetate dehalogenase, the carboxylate group performs a nucleophilic attack on the alpha-carbon atom, moving the halogen atom. this action is common to haloalkane dehalogenase and 4-chlorobenzoyl-coa dehalogenase. dl-2-haloacid dehalogenase is unique in that a water molecule directly attacks the substrate, displacing the halogen atom.