title: Artificial regulation of gene expression in Escherichia coli by RNase P.
abstract: Plasmids encoding various external guide sequences (EGSs) were constructed and inserted into Escherichia coli. In strains harboring the appropriate plasmids, the expression of fully induced beta-galactosidase and alkaline phosphatase activity was reduced by more than 50%, while no reduction in such activity was observed in strains with non-specific EGSs. The inhibition of gene expression was virtually abolished at restrictive temperatures in strains that were temperature-sensitive for RNase P (EC 3.1.26.5). Northern blot analysis showed that the steady-state copy number of EGS RNAs was several hundred per cell in vivo. A plasmid that contained a gene for M1 RNA covalently linked to a specific EGS reduced the level of expression of a suppressor tRNA that was encoded by a separate plasmid. Similar methods can be used to regulate gene expression in E. coli and to mimic the properties of cold-sensitive mutants.
mesh_terms: D001483:Base Sequence; D004722:Endoribonucleases / Q000502:physiology*; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics*; D029968:Escherichia coli Proteins; D015964:Gene Expression Regulation, Bacterial; D008969:Molecular Sequence Data; D009843:Oligoribonucleotides / Q000737:chemistry; D016372:RNA, Antisense / Q000737:chemistry; D012329:RNA, Bacterial / Q000235:genetics; D016337:RNA, Catalytic / Q000502:physiology*; D012333:RNA, Messenger / Q000235:genetics; D043262:Ribonuclease P; D013696:Temperature
chemical_list: D029968:Escherichia coli Proteins; D009843:Oligoribonucleotides; D016372:RNA, Antisense; D012329:RNA, Bacterial; D016337:RNA, Catalytic; D012333:RNA, Messenger; D004722:Endoribonucleases; D043262:Ribonuclease P; C470865:ribonuclease P, E coli