2dhc
CRYSTALLOGRAPHIC ANALYSIS OF THE CATALYTIC MECHANISM OF HALOALKANE DEHALOGENASE
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OverviewOverview
Crystal structures of haloalkane dehalogenase were determined in the presence of the substrate 1,2-dichloroethane. At pH 5 and 4 degrees C, substrate is bound in the active site without being converted; warming to room temperature causes the substrate's carbon-chlorine bond to be broken, producing a chloride ion with concomitant alkylation of the active-site residue Asp124. At pH 6 and room temperature the alkylated enzyme is hydrolysed by a water molecule activated by the His289-Asp260 pair in the active site. These results show that catalysis by the dehalogenase proceeds by a two-step mechanism involving an ester intermediate covalently bound at Asp124.
About this StructureAbout this Structure
2DHC is a Single protein structure of sequence from Xanthobacter autotrophicus with as ligand. Active as Haloalkane dehalogenase, with EC number 3.8.1.5 Full crystallographic information is available from OCA.
ReferenceReference
Crystallographic analysis of the catalytic mechanism of haloalkane dehalogenase., Verschueren KH, Seljee F, Rozeboom HJ, Kalk KH, Dijkstra BW, Nature. 1993 Jun 24;363(6431):693-8. PMID:8515812
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