title: Structure of secondary cleavage sites of E. coli RNAaseIII in A3t RNA from bacteriophage T7.
abstract: Five 'secondary' cleavage sites of E. coli RNAaseIII within the initiator RNA A3t (141 nucleotides) from bacteriophage T7 are described. Cleavage takes place apparEntly within or at the bottom of a short double-stranded stretch of RNA. Three secondary sites are efficiently cleaved in the presence of magnesium 2+ ions, two additional sites are cleaved in the presence of manganese 2+ ions at low monovalent salt concentrations (less than 0.05 M).
mesh_terms: D001483:Base Sequence; D004722:Endoribonucleases / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics*; D029968:Escherichia coli Proteins; D009690:Nucleic Acid Conformation; D012367:RNA, Viral / Q000235:genetics*; D043244:Ribonuclease III; D013379:Substrate Specificity; D013604:T-Phages / Q000235:genetics*
chemical_list: D029968:Escherichia coli Proteins; D012367:RNA, Viral; D004722:Endoribonucleases; D043244:Ribonuclease III; C468366:ribonuclease III, E coli