The sequence of the distal end of the E. coli ribosomal RNA rrnE operon indicates conserved features are shared by rrn operons

The 1440 nucleotides of the distal region of the E.coli ribosocial RNA operon found on the λaroE transducing phage has been sequenced. We show that the λaroE hybrid rrn operon ends after asolitary 5S RHA gene with rrnE distal sequence. A single terminator structure of dyad symmetry followed by a run of six T's has been identified and compared to other sequenced rrn terminator hairpins. Immediately adjacent to the hairpin is a region of interrupted but conserved sequence that is shared by rrnE, rrnB and rraD. An open reading frame of 127 ammo acids abuts the terminator structure. Another open reading frame of 147 amino acids is found on the opposite strand several hundred nucleotides dovnstream. © 1985 IRL Press Limited