Importance of different tfd genes for degradation of chloroaromatics by Ralstonia eutropha JMP134.
The tfdC(I)D(I)E(I)F(I,) and tfdD(II)C(II)E(II)F(II) gene modules of plasmid pJP4 of Ralstonia eutropha JMP134 encode complete sets of functional enzymes for the transformation of chlorocatechols into 3-oxoadipate, which are all expressed during growth on 2,4-dichlorophenoxyacetate (2,4-D). However, activity of tfd(I)-encoded enzymes was usually higher than that of tfd(II)-encoded enzymes, both in the wild-type strain grown on 2,4-D and in 3-chlorobenzoate-grown derivatives harboring only one tfd gene module. The tfdD(II)-encoded chloromuconate cycloisomerase exhibited special kinetic properties, with high activity against 3-chloromuconate and poor activity against 2-chloromuconate and unsubstituted muconate, thus explaining the different phenotypic behaviors of R. eutropha strains containing different tfd gene modules. The enzyme catalyzes the formation of an equilibrium between 2-chloromuconate and 5-chloro- and 2-chloromuconolactone and very inefficiently catalyzes dehalogenation to form trans-dienelactone as the major product, thus differing from all (chloro)muconate cycloisomerases described thus far.
Plumeier
Iris
I
Department of Environmental Biotechnology, GBF-German Research Center for Biotechnology, D-38124 Braunschweig, Germany.
Pérez-Pantoja
Danilo
D
Heim
Sabina
S
González
Bernardo
B
Pieper
Dietmar H
DH
D015084:2,4-Dichlorophenoxyacetic Acid / Q000378:metabolism; D000272:Adipates / Q000378:metabolism; D002265:Carboxylic Ester Hydrolases / Q000235:genetics / Q000378:metabolism*; D002396:Catechols / Q000378:metabolism; D002723:Chlorobenzoates / Q000378:metabolism; D003470:Culture Media; D020118:Cupriavidus necator / Q000201:enzymology / Q000235:genetics*; D049308:Dioxygenases; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D019753:Intramolecular Lyases / Q000235:genetics / Q000378:metabolism*; D006899:Mixed Function Oxygenases / Q000235:genetics / Q000378:metabolism*; D010088:Oxidoreductases / Q000235:genetics / Q000378:metabolism*; D044925:Oxidoreductases Acting on CH-CH Group Donors; D010105:Oxygenases / Q000235:genetics / Q000378:metabolism*; D010957:Plasmids; D013011:Sorbic Acid / Q000031:analogs & derivatives* / Q000378:metabolism
D000272:Adipates; D002396:Catechols; D002723:Chlorobenzoates; D003470:Culture Media; C036427:3-chlorobenzoic acid; D015084:2,4-Dichlorophenoxyacetic Acid; C088140:2-chloromuconic acid; C005939:muconic acid; D006899:Mixed Function Oxygenases; D010088:Oxidoreductases; D010105:Oxygenases; D049308:Dioxygenases; C044173:chlorocatechol 1,2-dioxygenase; C084087:2,4-dichlorophenoxyacetate-alpha-ketoglutarate dioxygenase; D044925:Oxidoreductases Acting on CH-CH Group Donors; C021530:maleylacetate reductase; D002265:Carboxylic Ester Hydrolases; C046130:carboxymethylenebutenolidase; D019753:Intramolecular Lyases; C055773:chloromuconate cycloisomerase; D013011:Sorbic Acid