title: Gal mRNA initiated within IS2.
abstract: A strain of E. coli carrying IS2 in the control region of the gal operon has been found to revert to a constitutive phenotype. These revertants can be divided into two classes, which differ in their rate of enzyme synthesis and gal transcription. One revertant synthesizes the gal messenger at a low level (low level revertants), the other at a higher level that exceeds that of the induced wild type two- to three-fold (high level revertants). In both cases it has been shown that the gal messenger is covalently bound to IS2-RNA, which is transcribed from IS2 in the original orientation. The evidence suggests, that the section of the IS2-element, from which this RNA is transcribed in the case of the high level revertants is smaller than 50 nucleotides long: i.e. the resolution of the hybridization method used for the detection of sequence homologies exceeds that of the electron microscopical heteroduplex technique.
mesh_terms: D003090:Coliphages; D004279:DNA, Viral; D004926:Escherichia coli; D005690:Galactose / Q000378:metabolism; D008242:Lysogeny; D009154:Mutation; D009693:Nucleic Acid Hybridization; D009876:Operon; D010957:Plasmids; D012329:RNA, Bacterial; D012333:RNA, Messenger; D012367:RNA, Viral; D014158:Transcription, Genetic
chemical_list: D004279:DNA, Viral; D012329:RNA, Bacterial; D012333:RNA, Messenger; D012367:RNA, Viral; D005690:Galactose