title: A ribonucleoprotein fragment of the 30 S ribosome of E. coli: evidence for long range RNA-RNA interactions.
abstract: A stable homogeneous ribonucleoprotein fragment of the 30 S ribosomal subunit of E. coli has been prepared by mild nuclease digestion and heating in a constant ionic environment. The fragment contains about half of the 16 S ribosomal RNa and six proteins: S4, S7, S9, S13, S16 and S19. The RNA moiety contains the reported binding sites of all six proteins. After deproteinization, 80% of the RNA migrated as two major electrophoretic bands, which were isolated and sequenced. Each band contained sequences from the 5' and 3' thirds of the 16 S RNA but none from the central third. That these two noncontiguous RNA domains migrated together electrophoretically in Mg++-containing gels after deproteinization constitutes direct evidence that the 16 S RNA is folded in the intact ribosome so as to bring the two domains close together and that there are RNA-RNA interactions between them in the presence of Mg++.
mesh_terms: D001483:Base Sequence; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000032:analysis*; D046911:Macromolecular Substances; D008970:Molecular Weight; D009698:Nucleoproteins / Q000032:analysis*; D012335:RNA, Ribosomal / Q000032:analysis*; D012261:Ribonucleoproteins / Q000032:analysis*; D012270:Ribosomes / Q000032:analysis*
chemical_list: D046911:Macromolecular Substances; D009698:Nucleoproteins; D012335:RNA, Ribosomal; D012261:Ribonucleoproteins