Editing Terminator (genetics) (section)

===Rho-independent terminators===
{{main|Intrinsic termination}}
[[Intrinsic termination|Intrinsic transcription terminators]] or Rho-independent terminators require the formation of a [[Nucleic acid thermodynamics|self-annealing]] [[Hairpin (genetics)|hairpin]] structure on the elongating transcript, which results in the disruption of the [[polymerase|mRNA-DNA-RNA polymerase ternary complex]]. The terminator sequence in DNA contains a 20 basepair GC-rich region of [[dyad symmetry]] followed by a short poly-A tract or "A stretch" which is transcribed to form the terminating hairpin and a 7–9 nucleotide "U tract" respectively. The mechanism of termination is hypothesized to occur through a combination of direct promotion of dissociation through [[allosteric regulation|allosteric effects]] of hairpin binding interactions with the RNA polymerase and "competitive kinetics".  The hairpin formation causes RNA polymerase stalling and destabilization, leading to a greater likelihood that dissociation of the complex will occur at that location due to increased time spent paused at that site and reduced stability of the complex.<ref name="von Hippel1998">{{cite journal|last1=von Hippel|first1=P. H.|title=An Integrated Model of the Transcription Complex in Elongation, Termination, and Editing|journal=Science|volume=281|issue=5377|year=1998|pages=660–665|doi=10.1126/science.281.5377.660|pmid=9685251|bibcode=1998Sci...281..660.|s2cid=11046390}}</ref><ref name="GusarovNudler1999">{{cite journal|last1=Gusarov|first1=Ivan|last2=Nudler|first2=Evgeny|title=The Mechanism of Intrinsic Transcription Termination|journal=Molecular Cell|volume=3|issue=4|year=1999|pages=495–504|issn=1097-2765|doi=10.1016/S1097-2765(00)80477-3|pmid=10230402|doi-access=free}}</ref>
Additionally, the elongation protein factor NusA interacts with the RNA polymerase and the hairpin structure to stimulate transcriptional termination.<ref name="Santangelo-2011">{{Cite journal  | last1 = Santangelo | first1 = TJ. | last2 = Artsimovitch | first2 = I. | title = Termination and antitermination: RNA polymerase runs a stop sign. | journal = Nat Rev Microbiol | volume = 9 | issue = 5 | pages = 319–29 |date=May 2011 | doi = 10.1038/nrmicro2560 | pmid = 21478900 | pmc=3125153}}</ref>