title: Effect of colicin E3 upon the 30S ribosomal subunit of Escherichia coli.
abstract: The properties of 30S ribosomal subunits from untreated and from colicin E3-treated (E3-30S) bacteria have been compared. Polyacrylamide gel electrophoresis of ribosomal proteins revealed no difference, but several studies indicated that the 16S RNA from E3-30S particles was modified. E3-16S RNA showed slightly increased resistance to heat-induced degradation and had a reduced (15 S) sedimentation coefficient on sucrose gradients. Fingerprint analyses of E3-16S RNA revealed that the 3'-terminus of the molecule had been deleted. It was concluded that a primary effect of colicin E3 is the activation of a highly specific RNase that degrades 30S ribosomal RNA in situ, and that the resulting fragment(s) are probably retained within the 30S particle.
mesh_terms: D001345:Autoradiography; D001426:Bacterial Proteins / Q000032:analysis; D002499:Centrifugation, Density Gradient; D003087:Colicins / Q000494:pharmacology*; D003720:Densitometry; D004589:Electrophoresis, Disc; D004926:Escherichia coli / Q000166:cytology*; D009698:Nucleoproteins / Q000032:analysis; D012335:RNA, Ribosomal / Q000378:metabolism; D012260:Ribonucleases / Q000378:metabolism; D012270:Ribosomes / Q000032:analysis / Q000187:drug effects*
chemical_list: D001426:Bacterial Proteins; D003087:Colicins; D009698:Nucleoproteins; D012335:RNA, Ribosomal; D012260:Ribonucleases