Transcription terminators are sections of the DNA sequence which mark the end of the gene in the genomic DNA during transcription. The transcription terminator provides signals that release the newly synthesised mRNA from the transcriptional complex. It also causes reactions which release RNA polymerase from the complex.
There are two types of transcription terminators the Rho-dependent and the Rho-independent in the prokaryotes. Rho-dependent terminators require a RHO factor which stimulates DNA helicase to unwind the double helix of DNA. Howver Rho-independent require the formation of a self-annealing hairpin which will unwind the double helix.
Lodish H, Berk A, Zipursky L, Matsudaira P, Baltimore D, Darnell JE. Molecular Cell Biology. 4th Ed, New York: W.H. Freeman & Co Ltd. 1999