Insights into the molecular mechanism of dehalogenation catalyzed by D-2-haloacid dehalogenase from crystal structures.

ABSTRACT: D-2-haloacid dehalogenases (D-DEXs) catalyse the hydrolytic dehalogenation of D-2-haloacids, releasing halide ions and producing the corresponding 2-hydroxyacids. A structure-guided elucidation of the catalytic mechanism of this dehalogenation reaction has not been reported yet. Here, we report the catalytic mechanism of a D-DEX, HadD AJ1 from Pseudomonas putida AJ1/23, which was elucidated by X-ray crystallographic analysis and the H₂¹⁸O incorporation experiment. HadD AJ1 is an α-helical hydrolase that forms a homotetramer with its monomer including two structurally axisymmetric repeats. The product-bound complex structure was trapped with L-lactic acid in the active site, which is framed by the structurally related helices between two repeats. Site-directed mutagene

SUBMITTER: Wang Y 

PROVIDER: S-EPMC5780510 | biostudies-literature | 2018 Jan

REPOSITORIES: biostudies-literature