RNA Processing (EUKARYOTES)

Question 1

Primary transcript

Answer 1

Created by RNA pol II; needs to undergo processing before translation

Question 2

5’ capping (5)

Answer 2

1) RTPase hydrolyzes phosphate from 5’ end
2) GTase hydrolyzes GTP and attaches GMP to base with phosphatase
3) guanylyl-7-methyltransferase attaches methyl group to N7 on guanine base
4) additional methyl groups added to 2’ OH on bases next to cap
5) Cap binding complex binds to 5’ cap to help with translation

Question 3

5’ cap functions (4)

Answer 3

protect against degradation, contributes to nuclear export, helps make RNA splicing more efficient, and contributed to initiation of translation

Question 4

3’ Polyadenylation (4)

Answer 4

Polyadenylation enzymes bound to CTD of RNA pol II
1) RNA pol II transcribes polyadenylation signal (AAUAAA)
2) Endonuclease cleaves RNA after signal
3) Poly A polymerase adds 80-250 A nucleotides to cleaved end with no template
4) Poly A binding protein binds to Poly A to rpotect from degradation