Transcription. Response to Comment on "Mechanism of eukaryotic RNA polymerase III transcription termination".

Arimbasseri et al., in their Comment, suggest that to terminate transcription in vivo, RNA polymerase III uses a mechanism other than hairpin-dependent termination and that properties of purified polymerase may depend on preparation procedure. Evidence suggests that our preparation is indeed different from that of other methods. Our new data suggest that, apart from hairpin-dependent termination, one or more "fail-safe" termination mechanisms may exist in the cell.