rrnB T1 terminator

The termination region of the rrnB gene coding for ribosomal RNA in Escherichia coli is large and complex. It contains two regions (T1 and T2) with typical factor-independent terminator-like sequences, two additional inverted repeats (lR1 and IR2) and a pair of direct repeats. The whole region is frequently employed as an efficient terminator of transcription in several cloning vectors. The rrnB T1 region was shown to be an efficient terminator in isolated form by Orosz et al. (1991).