BLG 888 Lecture Notes - Lecture 9: Transcription Preinitiation Complex, Transcription Bubble, Exonuclease
16 Jan 2017
School
Department
Course
Professor
Document Summary
Pol ii recruited to dna by transcription factors. Tfiid binds to promoter elements, acts as a landmark and causes a conformational change, then recruits tfiia and tfiib (which recognize bre). Rna pol ii bind followed by f e and h (all this forms the preinitiation complex) Preinitiation complex is converted to initiation complex by unwinding dna- formation of transcription bubble. During initiation, the ctd of pol ii is phosphorylated and some transcription factors are released. Exons: coding regions of dna introns: noncoding regions that interrupt coding region of dna. Rna processing- enzyme catalyzed addition of 5" cap the 5" end of eukaryotic mrna is capped- protects transcript from exonucleases. Helps to allow the mature mrna to be exported to the cytoplasm. A 5" cap is formed by adding a g to the terminal base of the transcript. Guanylyltransferase is associated with pol ii ctd to ensure that each mrna is capped as its transcribed.
