title: Reversion of ribosomal helix formation in Escherichia coli.
abstract: After transfer into fresh medium, Escherichia coli cells containing ribosomal helices resume growth without a lag period. The helices disappear within 15 min after transfer, the number of 70S ribosomes decreases, and a steady-state ribosomal profile appears within one cell generation time. Subunits isolated from the helices support in vitro protein synthesis, but efficiency is optimal only when supplemented with an undetermined factor that is contained in the S-100 fraction of log-phase cells. The data suggest a possible role of helices as ribosomal reserve units.
mesh_terms: D001426:Bacterial Proteins / Q000096:biosynthesis; D002247:Carbon Isotopes; D002455:Cell Division; D002474:Cell-Free System; D002499:Centrifugation, Density Gradient; D003470:Culture Media; D004926:Escherichia coli / Q000166:cytology* / Q000254:growth & development / Q000378:metabolism; D007930:Leucine / Q000378:metabolism; D008854:Microscopy, Electron; D010452:Peptide Biosynthesis; D010649:Phenylalanine / Q000378:metabolism; D011072:Poly U; D011132:Polyribosomes; D012270:Ribosomes / Q000378:metabolism; D014316:Tritium
chemical_list: D001426:Bacterial Proteins; D002247:Carbon Isotopes; D003470:Culture Media; D014316:Tritium; D011072:Poly U; D010649:Phenylalanine; D007930:Leucine