Inhibitory effect of a short Z-DNA forming sequence on transcription elongation by T7 RNA polymerase.

DNA sequences capable of forming unusual secondary structures can be a source of genomic instability. In some cases that instability might be affected by transcription, as recently shown for the Z-DNA forming sequence (CG)(14), which causes genomic instability both in mammalian cells and in bacteria, and this effect increases with its transcription. We have investigated the effect of this (CG)(14) sequence on transcription with T7 RNA polymerase in vitro.