EC Number   |
General Information |
Reference |
|---|
   3.8.1.10 | evolution |
Based on their substrate specificities and the configurations of their products, 2-HADs are classified into three types. DL-2-HADs catalyse the dehalogenation of both D- and L-2-haloalkanoic acids, inverting the stereochemistry at the Calpha-atom position and producing the corresponding L- and D-products, respectively. D- and L-2-HADs act specifically on only one enantiomer and cause inversion of Calpha-atom stereochemistry in the hydroxyalkanoic acid product. Enzymatic activity analysis of Pseudomonas syringae 2-HAD reveals its capacity to catalyse the dehalogenation of both L- and D-substrates, but the structure of ps-2-HAD is completely different from that of DehI, which is the only DL-2-HAD enzyme that is structurally characterized, bps-2-HAD shows similar overall folding to L-HADs. Thus ps-2-HAD has a distinct active site and a unique catalytic behaviour compared with other HADs |
732999 |
| 3.8.1.10 | evolution |
the reaction proceeds in two steps, in the first step, a catalytic aspartate residue nucleophilically attacks the alpha-carbon atom of the substrate to release the halide ion, resulting in the formation of an ester intermediate in which the aspartate residue is covalently bound to the alpha-carbon atom of the substrate. In the second step, the ester intermediate is hydrolyzed by a solvent water molecule. This mechanism is not restricted to this group of enzymes, e.g., fluoroacetate dehalogenase catalyzes the reaction in the same manner, although this enzyme is not evolutionarily related to the group II enzymes. Group I enzymes, including DL-2-haloacid dehalogenase and D-2-haloacid dehalogenase, catalyze the reaction without forming an ester intermediate. Instead, a solvent water molecule directly attacks the alpha-carbon atom of the substrate to release the halide ion. DL-2-haloacid dehalogenase is an extraordinary enzyme that acts on both enantiomers of the substrate |
733212 |
| 3.8.1.10 | more |
either the magnesium-binding cavity at least partially overlaps with the active site of ps-2-HAD or the coordinated residues or water molecules are involved directly in the catalytic reaction |
732999 |
| 3.8.1.10 | more |
modeling of binding pocket and the active site and QM/QM calculations, docking study using (R)- and (S)-2-chloropropionates, overview. The binding site cavity is shielded from the solvent region, and is composed of eight hydrophobic residues (Trp37, Ala39, Phe40, Gly41, Ala192, Phe273, Ile274, and Ile277), and five hydrophilic residues (Asn117, Tyr120, Ser193, Asp194, and Tyr270) |
733212 |
