Lecture 2

Question 1

What determines the transcription of genes?

Answer 1

Chromatin structure
RNA polymerase binding
Additional binding and activation factors

Question 2

Describe the histone code hypothesis

Answer 2

Proposes that specific combinations of chemical alterations are made to histones and DNA of chromatin to help determine chromatin configuration and influence transcription

Question 3

How are DNA loops unpacked when needed for transcription?

Answer 3

Histone modifying enzymes
RNA polymerase
Chromatin remodelling complexes

Question 4

What does TFIID do?

Answer 4

TBP subunit recognises TATA box

TAF subunit regulated binding of TBP

Question 5

What does TFIIB do?

Answer 5

positions RNA Pol at the txnal start site

Question 6

What does TFIIF do?

Answer 6

Stabilises RNA pol

Question 7

What does TFIIE do?

Answer 7

regulates TFIIH

Question 8

What does TFIIH do?

Answer 8

unwinds DNA, phosphorylates Ser5 of the RNA pol CTD

Question 9

Why does eukaryotic RNA polymerase need additional factors?

Answer 9

Cannot access DNA selectively
Additional factors mediate contact between upstream activators and basal factors. Upstream activators enhance speed of assembly

Question 10

What is an activator?

Answer 10

Binds to enhancers and stimulates txn of a gene.