Rho independent terminators

Rho- independent termination ( also known as intrinsic termination) is a process carried out in prokaryotic organisms as a mechanism for stopping Transcription. the mRNA molecule has a sequence of base pairs with a high proportion of Cytosine and Guanine bases, these are able to strongly bond to one another with 3 hydrogen bonds forming a RNA duplex in a stable hairpin structure¹. succeeding the hairpin structure is a chain of Uracil bases, which only form weak bonds with Adenine. the transcription of the uracil sequence is coupled with a protein, located on the RNA_polymerase, binding to the hairpin structure causing the RNA polymerase to temporarily stop². The temporary lapse and weak uracil- adenine bonds cause the hairpin structure to unwind and dissociate from the RNA polymerase, thus terminating transcription.

1. Lewin, Benjamin (2007). Genes IX. Sudbury, MA: Jones and Bartlett Publishers. ISBN 0-7637-4063-2.

2. Wilson KS, von Hippel PH (September 1995). "Transcription termination at intrinsic terminators: the role of the RNA hairpin". Proc. Natl. Acad. Sci. U.S.A. 92 (19): 8793–7.