BIOL 300 Lecture Notes - Lecture 12: Pyrimidine, Intron, Intergenic Region
16 Dec 2017
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Chapter 10. 1 10. 2: 5" capping, 3" cleavage and poly-adenylation are the main post-transcriptional modification, role of 5" and 3" caps > protects the pre-mrna from enzymatic digestion, all these processing events do not necessarily happen one after the. Other in this order : only capping has to happen first > splicing and poly-adenylation could happen in reverse order. The phosphate is removed in the first step of capping, while the remaining and phosphates (orange) remain associated with the cap. The third phosphate of the 5 ,5 triphosphate bond is derived from the phosphate of the gtp that donates the guanine. Figure 10-15 p. 431: cleavage and polyadenylation specificity factor (cpsf) binds to the upstream aauaaa polyadenylation signal. Cstf interacts with a downstream gu- or u-rich sequence and with bound. Cpsf, forming a loop in the rna; binding of cfi and cfii helps stabilize the complex.
