BIOL 303 1nd Edition Lecture 16 Outline of Last Lecture I. Transcriptiona. Role of chromatinII. Terminationa. Cappingb. Poly A tailIII. SplicingOutline of Current Lecture I. RNA SplicingCurrent LectureI. RNA Splicinga. There 3 different componentsi. Specific sequences: on the RNA that extinguishes introns and exons1. Present at every intron/exon and is highly conserved2. CAG (ending of an exon) – GU (starts an intron) – CAG (ends an intron) and demarks the sequence3. 2 ways to recognize:a. Proteinb. By other nucleotides – base pairingii. Splicisomes: recognizes and identifies the sequences1. Large multi-protien (RNA) sequence 2. 5 different complex, each has 10-15 different proteins contains 1 small RNA (U1, U2..)3. Small RNA are required for splicing because it bonds to exons and introns4. The U1 RNA base pairs with the sequences with the adenine group in the intron (A)5. Curved with protein. 2’ – OH of adenine does the cutting of the phoshposidester bond and the phosphate of the guanine gets a bond with the adenine 6. U5 cuts between the end of intron and beginning of exon and the larat (the closed loop) being released and destroyedThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.iii. Auto-hydrolysis: RNA is active; self containedII. Splicing defects: a. Destroys splice set: instead of CAG, it’s CAU and it doesn’t recognize as an intron and completely skips it because it thinks it’s at the beginning of an intron b. Alternative Splicing: primary transcript has too many exons that are used at one timei. Causes the protein to be different ii. Ex: fibroblast: skips the exons (7 and 10) 1. Muscle: skips the 7 and 11 this results in 2 different proteins (multiple genes)c. Wrap p53: primary transcript with multiple splicing product – spliciosomes must vary and alter and has to be very coordinatedd. Protein Domains: exons within you get entire domain i. Enzymes of protease with certain conditions ways – genes are made up ofexons and would be able to recombine into new
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