SEQUENCE AND EXPRESSION OF THE TODGIH GENES INVOLVED IN THE LAST 3 STEPS OF TOLUENE DEGRADATION BY PSEUDOMONAS-PUTIDA F1

The todFC1C2BADE gene cluster in Pseudomonas putida F1 encodes enzymes for the first four steps of toluene degradation, leading to the forma tion of 2-hydroxypenta-2,4-dienoate (HPD). Here, we report the nucleot ide (nt) sequence and expression of the remaining three genes of the t od pathway, downstream from todE and arranged in the order, todGIH. Th e deduced amino acid (aa) sequences of TodG [HPD hydratase (268 aa)], TodH [4-hydroxy-2-oxovalerate (HO) aldolase (352 aa)] and TodI [acylat ing aldehyde (AA) dehydrogenase (316 aa)] are compared with the isofun ctional proteins present in the meta-cleavage pathways of other bacter ia. New sequence motifs are identified. The highly conserved TodH and TodI sequences are potentially useful DNA probes for biomonitoring pur poses.