title: Eukaryotic ribosomal proteins stimulate Escherichia coli stringent factor to synthesize guanosine 5'-diphosphate, 3'-diphosphate (ppGpp) and guanosine 5'-triphosphate, 3'-diphosphate (ppGpp).
abstract: When supplemented with Escherichia coli stringent factor, 80S ribosomes from various sources failed to support guanosine tetra- and pentaphosphate ((p)ppGpp) synthesis. In contrast, ribosomal proteins from 80S, 60S or 40S particles (mouse embryos, rabbit reticulocytes) crossreacted with the E. coli stringent factor. Significant stimulation of (p)ppGpp synthesis was achieved with a concentration as low as 5 micrograms of ribosomal proteins/ml. These observations may provide additional crtieria to detect homologies between eukaryotic and prokaryotic ribosomal proteins.
mesh_terms: D001426:Bacterial Proteins / Q000494:pharmacology; D003429:Cross Reactions; D004926:Escherichia coli / Q000201:enzymology*; D006150:Guanine Nucleotides / Q000096:biosynthesis*; D006158:Guanosine Pentaphosphate / Q000096:biosynthesis*; D006159:Guanosine Tetraphosphate / Q000096:biosynthesis*; D006160:Guanosine Triphosphate; D010756:Phosphoric Acids; D010770:Phosphotransferases / Q000494:pharmacology*; D014176:Protein Biosynthesis; D012269:Ribosomal Proteins / Q000494:pharmacology*; D014158:Transcription, Genetic
chemical_list: D001426:Bacterial Proteins; D006150:Guanine Nucleotides; D010756:Phosphoric Acids; D012269:Ribosomal Proteins; D006159:Guanosine Tetraphosphate; D006158:Guanosine Pentaphosphate; D006160:Guanosine Triphosphate; D010770:Phosphotransferases