TY - JOUR
T1 - Structure of 2-haloacid dehalogenase from Pseudomonas syringae pv. tomato DC3000
AU - Hou, Zhiqiang
AU - Zhang, Hongmei
AU - Li, Mei
AU - Chang, Wenrui
PY - 2013/6
Y1 - 2013/6
N2 - 2-Haloacid dehalogenases (2-HADs) catalyse the hydrolytic dehalogenation of 2-haloalkanoic acids, cleaving the carbon-halide bond at the C α-atom position and releasing a halogen atom. These enzymes are of interest for their potential use in bioremediation and in the synthesis of industrial chemicals. Here, the crystal structure of 2-HAD from Pseudomonas syringae pv. tomato DC3000 (ps-2-HAD) at 1.98 14;Å resolution solved using the single-wavelength anomalous dispersion method is reported. The ps-2-HAD molecule consists of two structurally distinct domains: the core domain and the subdomain. Enzymatic activity analysis of ps-2-HAD revealed its capacity to catalyse the dehalogenation of both l- and d-substrates; however, the structure of ps-2-HAD is completely different from that of DehI, which is the only dl-2-HAD enzyme that has been structurally characterized, but shows similar overall folding to l-HADs. Single mutations of four amino-acid residues at the putative active site showed that they are related to its enzymatic activity, yet three of them are nonconserved among HADs. These observations imply that ps-2-HAD has a novel active site and a unique catalytic behaviour compared with other HADs. This study provides a structural basis and biochemical evidence for further elucidation of the catalytic mechanism of 2-HAD.
AB - 2-Haloacid dehalogenases (2-HADs) catalyse the hydrolytic dehalogenation of 2-haloalkanoic acids, cleaving the carbon-halide bond at the C α-atom position and releasing a halogen atom. These enzymes are of interest for their potential use in bioremediation and in the synthesis of industrial chemicals. Here, the crystal structure of 2-HAD from Pseudomonas syringae pv. tomato DC3000 (ps-2-HAD) at 1.98 14;Å resolution solved using the single-wavelength anomalous dispersion method is reported. The ps-2-HAD molecule consists of two structurally distinct domains: the core domain and the subdomain. Enzymatic activity analysis of ps-2-HAD revealed its capacity to catalyse the dehalogenation of both l- and d-substrates; however, the structure of ps-2-HAD is completely different from that of DehI, which is the only dl-2-HAD enzyme that has been structurally characterized, but shows similar overall folding to l-HADs. Single mutations of four amino-acid residues at the putative active site showed that they are related to its enzymatic activity, yet three of them are nonconserved among HADs. These observations imply that ps-2-HAD has a novel active site and a unique catalytic behaviour compared with other HADs. This study provides a structural basis and biochemical evidence for further elucidation of the catalytic mechanism of 2-HAD.
KW - 2-haloacid dehalogenases
KW - enzymatic activity
KW - mutation
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U2 - 10.1107/S0907444913006021
DO - 10.1107/S0907444913006021
M3 - Article
C2 - 23695255
AN - SCOPUS:84878276760
SN - 0907-4449
VL - 69
SP - 1108
EP - 1114
JO - Acta Crystallographica Section D: Biological Crystallography
JF - Acta Crystallographica Section D: Biological Crystallography
IS - 6
ER -