Structural and Functional Analysis of a Novel Haloalkane Dehalogenase with Two Halide-Binding Sites.
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Rok publikování | 2014 |
Druh | Článek v odborném periodiku |
Časopis / Zdroj | Acta Crystallographica D |
Fakulta / Pracoviště MU | |
Citace | |
Doi | http://dx.doi.org/10.1107/S1399004714009018 |
Obor | Biochemie |
Klíčová slova | haloalkane dehalogenase DbeA from Bradyrhizobium elkanii USDA94 |
Popis | Crystal structure of novel haloalkane dehalogenase DbeA revealed the presence of two chloride ions buried in the protein interior. The first halide-binding site is involved in substrate binding and is present in all structurally characterized haloalkane dehalogenases. The second halide-binding site is unique to DbeA. To elucidate the role of the second halide-binding site in enzyme functionality, a two-point mutant lacking this site was constructed and characterized. These substitutions resulted in a shift of substrate-specificity class and were accompanied by decrease of enzyme activity, stability and elimination of the substrate inhibition. The changes in enzyme catalytic activity were attributed to deceleration of the rate-limiting hydrolytic step, mediated by lower basicity of the catalytic histidine. |
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