Streptomycin was inactivated in the presence of ATP and magnesium ion by an enzyme preparation made from E. coli K 12 ML 1629 which is resistant to streptomycin. The structure of the inactivated streptomycin was determined, and it was found that the hydroxy group on C-3 of the N-methyl-L-glucosamine moiety of streptomycin is adenylylated.
