RNA

Question 1

3 types of RNA classes

Answer 1

Structural, Informational, Regulatory

Question 2

How does alpha amantin block transcription?

Answer 2

It prevents RNA pol II from translocating by binding the bridge helix.

Question 3

How does rifampicin block transcription?

Answer 3

It binds to bacterial RNA Pol and blocks the exit channel or “rectum” of the Pol.

Get it RRRifampicin RRRRectum?

Question 4

Which transcripts are part of the RNA pol II?

Answer 4

TFII D A B F E H

Question 5

Which TFII binds to the TATA box?

Answer 5

TFIID

Question 6

What is the role of TFII H?

Answer 6

1. Nucleotide excision repair
2. Helixase activity (XPB)
3. Phosphorylates C-terminus of Pol II (CDK 7)

Question 7

Which diseases are prominent in TFIII-H gene mutations?

Answer 7

Xeroderma Pigmentosum
Trichothiodystrophy
Cockaynes Syndrome

Question 8

What are the roles of the 5’cap?

Answer 8

Splicing
3' tail
Translocation through Nuclear pores
protects against degradation
Recriuits for translation

Question 9

What marks the beginning and end of an intron?

Answer 9

GU-AG

You GUUUU before you AGGGG (to the tune of Oooooohhhh AHHHhhhh)

Question 10

Describe the functions of U1, U2, and U2AF in splicing.

Answer 10

U1 binds to the GU on an intron.
U2 binds to “branch point A”
U2AF binds to the AG

Question 11

RNA Pol I can synthesize which type of RNA?

Answer 11

rRNA

Question 12

RNA Pol II can synthesize which type of RNA?

Answer 12

mRNA, snRNA, miRNA and lncRNA

Question 13

RNA Pol III can synthesize which type of RNA?

Answer 13

tRNA

Question 14

Describe the mechanism of splicing.

Answer 14

• During splicing mechanism, U1 brings Exon 1 close to the branch point A.
• The 2’ OH on the A attacks the phosphate on the end of exon 1— forming a lariat.
• Phosphate leaves exon 1.
• Free 3’OH on exon 1 attacks phosphate at head of Exon 2 and then joins Exons together.