FIG. 1.

Reactions (A) catalyzed by and genetic map (B and C) of the P. stutzeri OX1 locus coding for toluene/o-xylene monooxygenase. (A) I, R=H, toluene; R=CH₃, o-xylene; II, R=H, o-, m-, or p-cresol; R=CH₃, 2,3- or 3,4-DMP; III, R=H, 3-methylcatechol (4-methylcatechol can also be formed from cresols); R=CH₃, 3,4-dimethylcatechol. (B) Restriction endonuclease map of the DNA fragment expressing toluene/o-xylene monooxygenase activity (pBZ1260). Striped boxes represent the vector polylinker with relevant cloning sites. Sl, SalI; K, KpnI; Av, AvaI; N, NotI; Sm, SmaI; D, DraI; Bm, BamHI; Xb, XbaI; S, SalI. (C) The boxes indicate the ORFs identified (also see Table 2), and the points of the arrows indicate the direction of the transcription. In panel D, the mutations introduced in each ORF in turn are schematized (further details are reported in Materials and Methods).