terminatorsequentie
A terminatorsequentie is a DNA or RNA sequence that signals the termination of transcription. This process, by which a segment of DNA is copied into RNA, needs a clear stop signal to ensure that the RNA molecule is the correct length and that the transcription machinery disengages from the DNA template. In prokaryotes, terminator sequences often form a hairpin loop structure in the RNA molecule, which can physically stall the RNA polymerase. This hairpin is frequently followed by a string of uracil nucleotides, which destabilizes the RNA-DNA hybrid and facilitates the release of the RNA transcript. Different types of terminators exist, including Rho-dependent and Rho-independent terminators, each employing slightly different mechanisms to achieve termination.
In eukaryotes, the termination of transcription is more complex and often coupled with RNA processing events.