Fail‐safe termination elements: a common feature of the eukaryotic genome?

Abstract

A recent scan of the human genome (1) identified approximately 11 million hairpins. Some have been linked to known sequences, such as viruses, transposable elements, and, more recently, regulating or microRNAs, but the significance, if any, of most sequences that can be predicted to form hairpins remains unknown. Here we show that hairpins that are cleaved by RNase III- like nucleases can induce termination, even with normally polyadenylated transcripts, and that a cleaved hairpin downstream of a normal termination signal can induce fail-safe termination. Because such cleavage sites appear common to intergenic regions, the results raise the possibility that similar fail-safe termination elements are widely distributed in the eukaryotic genome to prevent read-through transcription from disrupting downstream promoter elements or opposing transcription.-Nabavi, S., Nazar, R. N. Fail-safe termination elements: a common feature of the eukaryotic genome?