In vitro degradation of guanosine 3',5'-bis(diphosphate) [ppGpp] by the spoT gene product [ppGppase] from auxotrophic strains of Escherichia coli: effects of various antibiotics and drugs.

The enzyme specifically hydrolyzing guanosine 3',5'-bis(diphosphate) [ppGpp] has been isolated from the ribosomal fraction of Escherichia coli; it released pyrophosphate from the 3'-position of ppGpp. The effects of various drugs and antibiotics known to interfere with protein and/or RNA synthesis were investigated in the ppGpp degrading reaction. It was determined that tetracycline, chlorotetracycline, and thiostrepton strongly inhibited the reaction, whereas levallorphan gave a moderate inhibition. Only the tetracycline-mediated inhibition could be reversed by manganese ions. Oxytetracycline, rifampicin, fusidic acid, kirromycin, streptomycin, puromycin, chloramphenicol, and morphine did not inhibit the decay reaction.