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. aeroginosa 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 acitivity. These antibodies cross-reacted with transferase from M. leteus and P. aeroginosa but not with proteins from other related bacteriam, 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.