| Abstract: | Coordination of GTP and 5-aminoimidazole-4-carboxamide riboside 5'-phosphate pools changes was studied. The CTP pool is an important component of Escherichia coli metabolism, while AICAR 5'-phosphate being one of alarmones controls the synthesis of GTP. Main attention was paid to histidine, the biosynthesis of which is connected with formation of purine nucleotides. The expression of the histidine operon and biosynthesis of histidine are shown to change the AICAR pool and help the formation of the GTP pool. The ribosomal antibiotics streptomycin and chloramphenicol may cause the temporary deficiency of GTP eliminated by the increase of alarmone AICAR pool. The latter event is concluded to cause the increase in GTP pool independent of the means of AICAR accumulation (C1-pholatedependent restriction of metabolization or, vice versa, the stimulation in the histidine biosynthesis pathway). |
