Plasmid-determined Dehalogenation of Haloacetates inMoraxellaSpecies

Reaction Mechanism of Fluoroacetate Dehalogenase from Moraxella sp. B

“…However, we found that the wild-type enzyme is not affected by toluene when suspended in a reaction mixture at a ratio of 10% (v/v). The reaction mixture containing 10 mol of Tris sulfate (pH 9.5), 0.75 mol of sodium hydroxide, the wild-type or the H272N mutant enzyme (1 mg each), and 10 l of toluene solution containing [1][2][3][4][5][6][7][8][9][10][11][12][13][14] C]chloroacetic acid in a final volume of 100 l was incubated at 30°C for 2 h. The reaction mixture was dialyzed against 50 mM potassium phosphate (pH 7.5) for 14 h and then applied to a C 18 reverse phase HPLC column. The elution was carried out with 0.05% trifluoroacetic acid for 5 min, followed by a linear gradient of 0 -80% acetonitrile in 0.05% trifluoroacetic acid as described above.…”

“…Kawasaki et al have also isolated a Moraxella strain producing the enzyme (13) and have cloned its gene in Escherichia coli (14). Two probable mechanisms can be delineated for the enzyme reaction (15).…”

Plasmid Analysis and Cloning of the Dichloromethane-utilization Genes of Methylobacterium sp. DM4

“…Transposition of the dcm region onto broad-host-range plasmids thus may be an essential step in spreading the Dcm+ phenotype. Tentative evidence for the occurrence of transposons encoding haloalkanoic acid dehalogenase structural genes has been obtained in Moraxella (Kawasaki et al, 1981) and in Pseudomonas putida PP3 (Slater et al, 1985). The cloned dcm genes will be useful to investigate the evolution and distribution of the DCM utilization system in facultatively methylotrophic soil bacteria.…”

A Mechanistic Analysis of Enzymatic Degradation of Organohalogen Compounds

“…FA1, catalyzes the hydrolytic defluorination of fluoroacetate to produce a fluoride ion and glycolate. [38][39][40] It is unique in that it catalyzes the cleavage of a strong carbon-fluorine bond of an aliphatic compound, whose dissociation energy is among the highest found in natural products. 41) Various dehalogenases, such as L-2-haloacid dehalogenase and DL-2-haloacid dehalogenase, catalyze the hydrolytic cleavage of a carbon-halogen bond, but fluoroacetate dehalogenase is the only example of an enzyme that catalyzes the hydrolytic cleavage of a carbon-fluorine bond.…”