Dehalogenation of 4-chlorobenzoate by 4-chlorobenzoate dehalogenase from pseudomonas sp. CBS3: an ATP/coenzyme A dependent reaction.
Pseudomonas sp. CBS3 was grown with 4-chlorobenzoate as sole source of carbon and energy. Freshly prepared cell-free extracts converted 4-chlorobenzoate to 4-hydroxybenzoate. After storage for 16 hours at 25 degrees C only about 50% of the initial activity was left. Treatment at 55 degrees C for 10 minutes, dialysis or desalting of the extracts by gel filtration caused a total loss of the activity of the 4-chlorobenzoate dehalogenase. The activity could be restored by the addition of ATP, coenzyme A and Mg2+. If one of these cofactors was missing, no dehalogenating activity was detectable. The amount of 4-hydroxybenzoate formed was proportional to the amount of ATP available in the test system whereas CoA served as a real coenzyme. A novel ATP/coenzyme A dependent reaction mechanism for the dehalogenation of 4-chlorobenzoate by 4-chlorobenzoate dehalogenase from Pseudomonas sp. CBS3 is proposed.
Löffler
F
F
Technische Universität Hamburg-Harburg, Arbeitsbereich Biotechnologie II, Germany.
Müller
R
R
Lingens
F
F
D000255:Adenosine Triphosphate / Q000378:metabolism; D002723:Chlorobenzoates / Q000378:metabolism*; D003065:Coenzyme A / Q000378:metabolism; D006867:Hydrolases / Q000378:metabolism*; D007700:Kinetics; D008274:Magnesium / Q000494:pharmacology; D011549:Pseudomonas / Q000201:enzymology*
D002723:Chlorobenzoates; D000255:Adenosine Triphosphate; D006867:Hydrolases; C042846:4-chlorobenzoate dehalogenase; D008274:Magnesium; C040768:4-chlorobenzoic acid; D003065:Coenzyme A