title: Mechanism of protein synthesis inhibition during stationary phase in Bacillus stearothermophilus.
abstract: The appearance of a protein (association factor I) in ribosomes from Bacillus stearothermophilus at stationary phase of growth is described. Association factor I is present on 30S subunits and 30S-50S ribosomal couples, but not on 50S subunits. This protein is responsible for the low levels of polyphenylalanine synthesis shown by stationary phase ribosomes. Association factor I is able to bind to free 30S-50S ribonsomal couples but not to polysomes, and exerts its effect by inhibiting the initiation step of protein synthesis. Ribonsomes preincubated with association factor I have a decreased ability for polypeptide synthesis directed page mRNA or poly(U).
mesh_terms: D001426:Bacterial Proteins / Q000494:pharmacology*; D002453:Cell Cycle; D003090:Coliphages; D001411:Geobacillus stearothermophilus / Q000502:physiology*; D010452:Peptide Biosynthesis; D010442:Peptide Chain Initiation, Translational / Q000187:drug effects*; D010455:Peptides; D010649:Phenylalanine / Q000031:analogs & derivatives / Q000096:biosynthesis; D011072:Poly U / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D012367:RNA, Viral / Q000378:metabolism; D012269:Ribosomal Proteins / Q000494:pharmacology*; D012270:Ribosomes / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D010455:Peptides; D012333:RNA, Messenger; D012367:RNA, Viral; D012269:Ribosomal Proteins; D011072:Poly U; C012001:polyphenylalanine; D010649:Phenylalanine