Role of the translocation factor G in the regulation of ribonucleic acid synthesis.
In an Escherichia coli rel(+)arg strain (ES-2) which carries a temperature-sensitive "G factor," the synthesis of ribonucleic acid (RNA) continues at the nonpermissive temperature (42 C) even though protein synthesis is terminated. However, at 32 C, the strain exhibits a stringent control of RNA synthesis in the absence of arginine. The stringent control of RNA synthesis imposed by trimethoprim (an inhibitor of initiation of protein synthesis) at 32 C is released at the nonpermissive temperature. Even the diauxie lag in RNA synthesis, which is regulated independently of the allelic state of the rel gene, is overcome by inactivation of the G factor. The unusual guanosine nucleotide, guanosine 5'-diphosphate 2' or 3'-diphosphate (ppGpp), is produced in small amounts during growth in strain ES-2. Withdrawal of arginine results in a greater accumulation of this compound at 32 C. At 42 C, the synthesis of ppGpp is abolished and is considerably lower than the level found in ES-2 under normal growth conditions. These results indicate that the translocation factor G plays an important role in the regulation of RNA synthesis and in the synthesis of ppGpp.
D001120:Arginine / Q000378:metabolism; D001426:Bacterial Proteins / Q000096:biosynthesis; D002247:Carbon Isotopes; D002855:Chromatography, Thin Layer; D004926:Escherichia coli / Q000254:growth & development / Q000378:metabolism*; D005809:Genes, Regulator; D005947:Glucose / Q000378:metabolism; D006150:Guanine Nucleotides / Q000096:biosynthesis* / Q000378:metabolism; D007930:Leucine / Q000378:metabolism; D010445:Peptide Elongation Factors; D010759:Phosphorus Isotopes; D012329:RNA, Bacterial / Q000096:biosynthesis*; D013386:Succinates / Q000378:metabolism; D013696:Temperature; D014295:Trimethoprim / Q000494:pharmacology; D014364:Tryptophan / Q000378:metabolism; D014498:Uracil / Q000378:metabolism
D001426:Bacterial Proteins; D002247:Carbon Isotopes; D006150:Guanine Nucleotides; D010445:Peptide Elongation Factors; D010759:Phosphorus Isotopes; D012329:RNA, Bacterial; D013386:Succinates; D014498:Uracil; D014364:Tryptophan; D001120:Arginine; D014295:Trimethoprim; D007930:Leucine; D005947:Glucose