title: Defect in the split proteins of 30-S ribosomal subunits and under-methylation of 16-S ribosomal RNA in a polyamine-requiring mutant of Escherichia coli grown in the absence of polyamines.
abstract: Polyphenylalanine synthesis was carried out with Escherichia coli Q13 50-S ribosomal subunits and reconstituted 30-S particles containing different combinations of 23-S core particles and 30-S subunit split proteins obtained from a polyamine-requiring mutant of E. coli during its growth in the presence or absence of putrescine. It was concluded that the defect in the amount of some kinds of 30-S subunit split proteins was responsible for the decrease of polypeptide synthesis in a polyamine-requiring mutant of E. coli grown in the absence of polyamines. The methylation of 16-S RNA during growth in the absence of putrescine was decreased, while the degree of methylation of 23-S RNA did not change significantly. The decrease in methylation of 16-S RNA in the absence of putrescine was due mainly to a decrease of methylation of adenine. The relationship between the decrease of polypeptide synthetic activity of 30-S ribosomal subunits obtained from a polyamine-requiring mutant of E. coli grown in the absence of polyamines and the decrease of methylation of 16-S RNA is discussed.
mesh_terms: D000617:Aminoglycosides; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D004926:Escherichia coli / Q000187:drug effects / Q000378:metabolism*; D008274:Magnesium / Q000494:pharmacology; D008745:Methylation; D009154:Mutation; D009239:N-Formylmethionine; D014176:Protein Biosynthesis / Q000187:drug effects; D011700:Putrescine / Q000494:pharmacology*; D012335:RNA, Ribosomal / Q000378:metabolism*; D012343:RNA, Transfer / Q000378:metabolism; D012269:Ribosomal Proteins / Q000096:biosynthesis*; D012270:Ribosomes / Q000187:drug effects / Q000378:metabolism*; D013095:Spermidine / Q000494:pharmacology*
chemical_list: D000617:Aminoglycosides; D000900:Anti-Bacterial Agents; D012335:RNA, Ribosomal; D012269:Ribosomal Proteins; D009239:N-Formylmethionine; D012343:RNA, Transfer; D008274:Magnesium; D013095:Spermidine; D011700:Putrescine