title: Reaction mechanism of cis-3-chloroacrylic acid dehalogenase: a theoretical study.
abstract: The reaction mechanism of cis-3-chloroacrylic acid dehalogenase (cis-CaaD) is studied using the B3LYP density functional theory method. This enzyme catalyzes the hydrolytic dehalogenation of cis-3-chloroacrylic acid to yield malonate semialdehyde and HCl. The uncatalyzed reaction is first considered, and excellent agreement is found between the calculated barrier and the measured rate constant. The enzymatic reaction is then studied with an active site model consisting of 159 atoms. The results suggest an alternative mechanism for cis-CaaD catalysis and different roles for some active site residues in this mechanism.
authors.affiliation: Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden.
authors.forename: Robin
authors.initials: R
authors.lastname: Sevastik
authors.forename: Christian P
authors.initials: CP
authors.lastname: Whitman
authors.forename: Fahmi
authors.initials: F
authors.lastname: Himo
mesh_terms: D002384:Catalysis; D020134:Catalytic Domain; D004734:Energy Metabolism; D006867:Hydrolases / Q000737:chemistry* / Q000378:metabolism*; D006868:Hydrolysis; D008956:Models, Chemical; D011549:Pseudomonas / Q000201:enzymology* / Q000378:metabolism; D055672:Static Electricity; D013379:Substrate Specificity; D014867:Water / Q000378:metabolism
chemical_list: D014867:Water; D006867:Hydrolases; C077719:cis-3-chloroacrylic acid dehalogenase