title: The occurrence of 2'-5' oligoadenylates in Escherichia coli.
abstract: The use of a highly specific radioimmunoassay and of HPLC permitted us to confirm the occurrence of 2'-5' oligoadenylates [p chi (A2'p5')nA] in several strains of Escherichia coli. Cellular concentrations of 2'-5' oligoadenylates ranged from 50 nM to 300 nM. The mixture of 2'-5' oligoadenylates consisted primarily of pppA2'p5'A, pA2'p5'A,A2'p5'Ap and A2'p5'A under normal conditions of growth. None of them activated RNase L. Infection of the bacteria with the single-stranded DNA phage M13 or induction of a heat-inducible, non-lytic mutant of phage lambda led to a significant increase in the total pool of 2'-5' oligoadenylates, paralleling the progressive inhibition of growth. Likewise, the inhibition of protein synthesis with chloramphenicol stimulated the accumulation of 2'-5' oligoadenylates. Furthermore, the inhibition of bacterial growth by either phage or by chloramphenicol brought about a change in the composition of the 2'-5' oligoadenylate pool; 5'-phosphorylated 2'-5' oligoadenylates accumulated and became the major components. The findings indicate a parallelism between the effects of viral infection on the synthesis of 2'-5' oligoadenylates in eukaryotes and similar effects subsequent to phage growth in the bacterium E. coli.
mesh_terms: D000227:Adenine Nucleotides / Q000032:analysis* / Q000378:metabolism / Q000494:pharmacology; D001426:Bacterial Proteins / Q000096:biosynthesis; D010582:Bacteriophage lambda / Q000378:metabolism; D001435:Bacteriophages / Q000502:physiology; D002701:Chloramphenicol / Q000494:pharmacology; D002851:Chromatography, High Pressure Liquid; D004722:Endoribonucleases / Q000378:metabolism; D004789:Enzyme Activation / Q000187:drug effects; D004926:Escherichia coli / Q000032:analysis* / Q000187:drug effects / Q000378:metabolism; D006358:Hot Temperature; D009843:Oligoribonucleotides / Q000032:analysis* / Q000378:metabolism / Q000494:pharmacology; D011863:Radioimmunoassay
chemical_list: D000227:Adenine Nucleotides; D001426:Bacterial Proteins; D009843:Oligoribonucleotides; C023505:2',5'-oligoadenylate; D002701:Chloramphenicol; D004722:Endoribonucleases; C031956:2-5A-dependent ribonuclease