title: Identification of a precursor molecular for the RNA moiety of the processing enzyme RNase P.
abstract: A precursor molecule for 10Sb (M1) RNA, the RNA moiety of the RNA processing enzyme ribonuclease P (EC 3.1.26.5), is accumulated transiently in an Escherichia coli strain containing a plasmid that carries the 10Sb RNA gene. The same RNA precursor molecule is accumulated, in relatively large quantities, in a temperature-sensitive RNase E- mutant at the nonpermissive temperature. The RNA precursor includes 10Sb RNA and an extra 3' fragment that contains a termination stem and loop. It can be processed in vitro to a molecule the size of 10Sb RNA. None of the four endoribonucleases of E. coli--RNase III, RNase E, RNase F, or RNase P--takes part in this cleavage reaction. Therefore, we suggest that the processing of the precursor-10Sb RNA to 10Sb RNA is carried out by a thus-far unidentified endoribonuclease. The accumulation of a RNA molecule in a RNase E- mutant that does not contain a cleavage site for RNase E has been encountered previously and can be explained by assuming the existence of a RNA processing complex in the E. coli cell.
mesh_terms: D001483:Base Sequence; D004722:Endoribonucleases / Q000235:genetics*; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics; D029968:Escherichia coli Proteins; D009154:Mutation; D009694:Nucleic Acid Precursors / Q000235:genetics*; D009843:Oligoribonucleotides / Q000032:analysis; D012322:RNA Precursors; D012329:RNA, Bacterial / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics*; D043262:Ribonuclease P; D006163:Ribonuclease T1
chemical_list: D029968:Escherichia coli Proteins; D009694:Nucleic Acid Precursors; D009843:Oligoribonucleotides; D012322:RNA Precursors; D012329:RNA, Bacterial; D012333:RNA, Messenger; D004722:Endoribonucleases; D043262:Ribonuclease P; C470865:ribonuclease P, E coli; D006163:Ribonuclease T1