title: Processing of the 17-S Escherichia coli precursor RNA in the 27-S pre-ribosomal particle.
abstract: An RNase activity probably involved in the maturation of 16-S pre-ribosomal RNA in Escherichia coli has been partially purified from crude cell extracts. When 27-S ribosome precursor particles are incubated with this enzyme preparation in vitro, their 17-S RNA is converted to a product with the same electrophoretic mobility as mature 16-S rRNA. Fingerprint analysis of this product shows that it contains the 3'-OH but not the 5'-P terminus of mature 16-S rRNA. Generation of the normal 5'-P terminus seems to require a factor present in cell extracts since incubation of the 27-S precursor particle in an extract obtained after centrifugation at 30 000 x g causes conversion of the 17-S RNA to a 16-S species containing both termini of mature 16-S rRNA. Preliminary experiments suggest that correct maturation of the 5' end of the 17-S precursor RNA requires a system in which protein synthesis can take place.
mesh_terms: D002458:Cell Fractionation; D004926:Escherichia coli / Q000378:metabolism*; D007700:Kinetics; D008970:Molecular Weight; D009154:Mutation; D012335:RNA, Ribosomal / Q000096:biosynthesis / Q000378:metabolism*; D012260:Ribonucleases / Q000378:metabolism*; D012270:Ribosomes / Q000378:metabolism* / Q000648:ultrastructure
chemical_list: D012335:RNA, Ribosomal; D012260:Ribonucleases