| Title : Bacterial 2,4-dioxygenases: new members of the alpha\/beta hydrolase-fold superfamily of enzymes functionally related to serine hydrolases - Fischer_1999_J.Bacteriol_181_5725 |
| Author(s) : Fischer F , Kunne S , Fetzner S |
| Ref : Journal of Bacteriology , 181 :5725 , 1999 |
| Abstract : 1H-3-hydroxy-4-oxoquinoline 2,4-dioxygenase (Qdo) from Pseudomonas putida 33/1 and 1H-3-hydroxy-4-oxoquinaldine 2,4-dioxygenase (Hod) from Arthrobacter ilicis Ru61a catalyze an N-heterocyclic-ring cleavage reaction, generating N-formylanthranilate and N-acetylanthranilate, respectively, and carbon monoxide. Amino acid sequence comparisons between Qdo, Hod, and a number of proteins belonging to the alpha/beta hydrolase-fold superfamily of enzymes and analysis of the similarity between the predicted secondary structures of the 2,4-dioxygenases and the known secondary structure of haloalkane dehalogenase from Xanthobacter autotrophicus GJ10 strongly suggested that Qdo and Hod are structurally related to the alpha/beta hydrolase-fold enzymes. The residues S95 and H244 of Qdo were found to be arranged like the catalytic nucleophilic residue and the catalytic histidine, respectively, of the alpha/beta hydrolase-fold enzymes. Investigation of the potential functional significance of these and other residues of Qdo through site-directed mutagenesis supported the hypothesis that Qdo is structurally as well as functionally related to serine hydrolases, with S95 being a possible catalytic nucleophile and H244 being a possible catalytic base. A hypothetical reaction mechanism for Qdo-catalyzed 2,4-dioxygenolysis, involving formation of an ester bond between the catalytic serine residue and the carbonyl carbon of the substrate and subsequent dioxygenolysis of the covalently bound anionic intermediate, is discussed. |
| ESTHER : Fischer_1999_J.Bacteriol_181_5725 |
| PubMedSearch : Fischer_1999_J.Bacteriol_181_5725 |
| PubMedID: 10482514 |
| Gene_locus related to this paper: psepu-QDO |
| Gene_locus related to this paper: psepu-QDO |
Fischer F, Kunne S, Fetzner S (1999)
Bacterial 2,4-dioxygenases: new members of the alpha\/beta hydrolase-fold superfamily of enzymes functionally related to serine hydrolases
Journal of Bacteriology
181 :5725
Fischer F, Kunne S, Fetzner S (1999)
Journal of Bacteriology
181 :5725