title: Evidence that 16S RNA from E. coli can assume two different biologically active conformations.
abstract: We have recently shown that 16S RNA can be extracted from 30S ribosomes by an acetic acid-urea precipitation procedure which yields RNA capable of binding 13 individual ribosomal proteins. This is in contrast to phenol extracted 16S RNA which can specifically associate with only 7 proteins2-7. In the experiments reported here, we demonstrate that the difference in protein binding capacities is due to a relatiely more "open" configuration possessed by the acetic acid-urea 16S RNA. Under identical conditions, acetic acid-urea 16S RNA is more susceptible to limited T1-RNase digestion than is phenol-16S RNA. In addition, acetic acid-urea RNA shows a relatively slower electrophoretic mobility. The observable difference in conformation between the two types of RNA is lost by storage at-70 degrees C. This loss is accompanied by a reduction in protein binding capacity of the acetic acid-urea 16S RNA.
mesh_terms: D001483:Base Sequence; D001665:Binding Sites; D002499:Centrifugation, Density Gradient; D004355:Drug Stability; D004587:Electrophoresis, Agar Gel; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000378:metabolism*; D007700:Kinetics; D046911:Macromolecular Substances; D008970:Molecular Weight; D009690:Nucleic Acid Conformation; D010636:Phenols; D011485:Protein Binding; D012335:RNA, Ribosomal / Q000378:metabolism; D012260:Ribonucleases / Q000378:metabolism; D012269:Ribosomal Proteins / Q000378:metabolism; D012270:Ribosomes / Q000378:metabolism; D014508:Urea
chemical_list: D046911:Macromolecular Substances; D010636:Phenols; D012335:RNA, Ribosomal; D012269:Ribosomal Proteins; D014508:Urea; D012260:Ribonucleases