BI226 Lecture Notes - Lecture 6: Repressor, Nuclear Membrane, Consensus Sequence
Document Summary
When transcription of the gene is completed, the 5" end of the rna trails off the core enzyme. The core enzyme dissociates from the dna. Shortly after one round of transcription is initiated, a second round begins. Intrinsic termination: mechanism dependent only on the presence of the repeat induces a secondary structure needed for termination. Requires a different termination sequence and the rho protein. Composed of an inverted repeat followed by a string of adenines. Mrna folds into a short stem-loop structure, called a hairpin (g-c rich regions) Hairpin followed by series of u"s in the mrna causes the rna polymerase to slow down. Instability caused by the slowing rna pol and the u-a base pairs induces rna pol to fall off the transcript and separate from the dna. Certain bacterial genes require the action of the rho protein to bind to the nascent mrna and catalyze the separation of the mrna from the rna polymerase.
