title: The meta cleavage operon of TOL degradative plasmid pWW0 comprises 13 genes.
abstract: The meta-cleavage operon of TOL plasmid pWW0 of Pseudomonas putida encodes a set of enzymes which transform benzoate/toluates to Krebs cycle intermediates via extradiol (meta-) cleavage of (methyl)catechol. The genetic organization of the operon was characterized by cloning of the meta-cleavage genes into an expression vector and identification of their products in Escherichia coli maxicells. This analysis showed that the meta-cleavage operon contains 13 genes whose order and products (in kilodaltons) are xylX(57)-xylY(20)-xylZ(39)-xylL(28)-xylT(1 2)-xylE(36)-xylG(60)-xylF(34)- xylJ(28)-xylQ(42)-xylK(39)-xylI(29)-xylH(4 ). The xylXYZ genes encode three subunits of toluate 1,2-dioxygenase. The xylL, xylE, xylG, xylF, xylJ, xylK, xylI, and xylH genes encode 1,2-dihydroxy-3,5-cyclohexadiene-1-carboxylate dehydrogenase, catechol 2,3-dioxygenase, 2-hydroxymuconic semialdehyde dehydrogenase, 2-hydroxymuconic semialdehyde hydrolase, 2-oxopent-4-enoate hydratase, 4-hydroxy-2-oxovalerate aldolase, 4-oxalocrotonate decarboxylase and 4-oxaloccotonate tautomerase, respectively. The functions of xylT and xylQ are not known at present. The comparison of the coding capacity and the sizes of the products of the meta-cleavage operon genes indicated that most of the DNA between xylX and xylH consists of coding sequences.
authors.affiliation: Department of Medical Biochemistry, University of Geneva, Switzerland.
authors.forename: S
authors.initials: S
authors.lastname: Harayama
authors.forename: M
authors.initials: M
authors.lastname: Rekik
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics*; D003001:Cloning, Molecular; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000235:genetics; D005798:Genes, Bacterial; D009876:Operon; D010957:Plasmids; D011549:Pseudomonas / Q000201:enzymology / Q000235:genetics*; D015183:Restriction Mapping
chemical_list: D001426:Bacterial Proteins