Terminator (genetics)

In genetics, a terminator, or transcription terminator is a section of genetic sequence that marks the end of gene or operon on genomic DNA for transcription.

In prokaryotes, two classes of transcription terminators are known:
 * 1) Intrinsic transcription terminators where a hairpin structure forms within the nascent transcript that disrupts the mRNA-DNA-RNA polymerase ternary complex.
 * 2) Rho-dependent transcription terminators that require Rho factor, an RNA helicase protein complex, to disrupt the nascent mRNA-DNA-RNA polymerase ternary complex.

In eukaryotes, terminators are recognized by protein factors and termination is followed by polyadenylation.