Nitroaromatics Are Substrates for the TOL Plasmid Upper-Pathway Enzymes.
Expression of the xylMA genes encoding for toluene monoxygenase from the lactose promoter in a broad-host-range plasmid allows the oxidation of toluene and m- and p-nitrotoluene to their corresponding benzyl alcohols and benzaldehydes in Pseudomonas putida and Escherichia coli. Benzyl alcohols accumulate until reaching a concentration of about 80 muM, while benzaldehydes accumulate steadily with time for at least 24 h. TOL-encoded benzyl alcohol dehydrogenase and benzaldehyde dehydrogenase recognize m- and p-nitro-substituted compounds as substrates. In contrast, the XylR protein, which regulates the TOL plasmid-encoded upper-pathway operon, does not recognize nitro-substituted toluenes as effectors.
Delgado
A
A
Departamento de Bioquímica Vegetal, Consejo Superior de Investigaciones Científicas, Estación Experimental del Zaidín, Apto. 419, 18080 Granada, Spain, and Department of Biochemistry, University of Groningen, Groningen, The Netherlands.
Wubbolts
M G
MG
Abril
M A
MA
Ramos
J L
JL