Polyclonal antibodies against O6-methylguanine-DNA methyltransferase in adapted bacteria

The similarity of the adaptive response and the methyltransferase component in bacterial strains from different phylogenic groups was investigated. An adaptive response with induction of transferase activity was found for the first time in the soil bacteria P. aeruginosa and X. maltophilia. Polyclonal antibodies against the E. coli ada protein were used to investigate the structural similarity of the transferases from several bacterial strains with adaptive responses and inducible transferase activity. These antibodies cross-reacted with transferase from M. luteus and P. aeruginosa but not with proteins from other related bacteria, and not with human transferase. The phylogenic relationships of bacteria with adaptive responses suggest that the response likely was present in the common ancestor of eubacteria. The restricted antibody cross-reactivity may reflect the dual role of the E. coli ada protein not only in DNA repair but in positive gene regulation.