title: Methylcatechol 1,2-dioxygenase of Rhodococcus opacus 6a is a new type of the catechol-cleaving enzyme.
abstract: The strains Rhodococcus sp. 400, R. rhodochrous 172, and R. opacus 6a utilize 4-methylbenzoate as the only carbon and energy source. 4-Methylcatechol is a key intermediate of biodegradation. Its further conversion by all the strains proceeds via ortho-cleavage. The specific activity of catechol 1,2-dioxygenase assayed in crude extracts of Rhodococcus sp. 400 and R. rhodochrous 172 with 3- and 4-methylcatechols does not exceed the enzyme activity assayed with catechol. Two catechol 1,2-dioxygenases have been purified from the biomass of R. opacus strain 6a grown with 4-methylbenzoate. These enzymes differed in molecular mass and physicochemical and catalytic properties. One of these enzymes belongs to the type of enzymes cleaving the catechol ring and known as methylcatechol 1,2-dioxygenases. In bacteria of the Rhodococcus genus, such an enzyme is described here for the first time.
authors.affiliation: Skryabin Institute of Biochemistry and Physiology of Microorganisms, Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russia.
authors.forename: I P
authors.initials: IP
authors.lastname: Solyanikova
authors.forename: E I
authors.initials: EI
authors.lastname: Konovalova
authors.forename: L A
authors.initials: LA
authors.lastname: Golovleva
mesh_terms: D002384:Catalysis; D002396:Catechols / Q000378:metabolism*; D049308:Dioxygenases / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D004795:Enzyme Stability; D006868:Hydrolysis; D008970:Molecular Weight; D012240:Rhodococcus / Q000201:enzymology* / Q000254:growth & development
chemical_list: D002396:Catechols; C056893:3-methylcatechol 2,3-dioxygenase; D049308:Dioxygenases; C034221:catechol