Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

CMB2001 > lecture 3 recap > Flashcards

lecture 3 recap Flashcards

1
Q

what are the 3 ways activators promote transcription

A
  1. promote binding of an additional activator.
  2. stimulate complex assembly (pol II to bind to TATA)
  3. release stalled RNA pol II
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what small protein composes chromatin

A

histones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what are the 2 types of histones

A

core histones and linker histones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what are the 4 types of core histones

A

H2A, H2B, H3, H4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

core histones have a globular domain made up of

A

alpha helices and loops

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

core histones also have an N terminal rich in

A

Lysine and arginine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what does the globular domain folds into

A

a histone fold

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

the histone folds from different core histones interacts to form what?

A

handshake interaction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is an octamer

A

central H3-H4 tetramer and 2 flanking H2A-H2B dimers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

the core histones form repeating units called

A

nucleosomes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what is a nucleosome

A

around 247bp of DNA wrapped twice around an octamer of histone proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

DNA passes directly from one nucleosome to

A

the next nucleosome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what binds to the DNA between nucleosomes

A

linker histones such as histone H1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what are the 3 main mechanisms for modulating the structure if chromatin

A

histone variants
post-translational modification of histones
ATP dependent chromatin remodelling

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

histone variants are

A

alternative histones to the core histones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

all histones have variants except

A

H4

17
Q

histone variants change what

A

the structural and functional properties of the nucleosome

18
Q

post translational modification of histones is

A

modification of the N terminal tails

19
Q

what are examples of modification of the N terminal tails

A

acetylation
methylation
ubiquitination
phosphorylation

20
Q

the modification state of the histone dictates the

A

transcriptional state of the DNA, referred to as the histone code

21
Q

what is histone acetylation mediated by

A

HATs (histone acetyl transferases)

22
Q

histone acetylation occurs on?

A

lysine residues in the N terminal tail

23
Q

what is histone acetylation reversed by

A

HDACs (histone deacetylases) through hydrolysis

24
Q

high levels of acetylation correlates with

A

high levels of transcription

25
Q

what are the 2 major types of HATs

A

GNAT family and MYST family

26
Q

how are HATs recruited to chromatin

A

HATs contain a specific subunit that interacts with activators therefore the activator brings the HATs to the promoters

27
Q

acetylation causes what change to the lysine

A

the charge to be reduced

28
Q

therefore the positively charge lysine can no longer interact with what?

A

negatively charged DNA making the chromatin less compact and easier for transcription to occur

29
Q

acetylation of lysine also allows which proteins to recognise the DNA

A

proteins containing bromodomains

30
Q

what do proteins containing bromodomains promote

A

transcription

31
Q

bromodomain Bdf1 binds to what

A

acetylated H4

32
Q

what does this recruit

A

TFIID

33
Q

histone methylation can occur on

A

lysine and arginine residues

34
Q

what proteins methylates lysine

A

histone lysine methyl transferases (HKMTs)

35
Q

HKMTs add up to how many methyl groups

A

3

36
Q

what reverses the methylation of lysine

A

lysine demethylases

37
Q

does methylation affect the charge of the lysine

A

no, meaning it only has a small affect of chromatin structure

38
Q

methylated lysines act as a binding site for binding modules e.g.

A

chromodomains

39
Q

methylation on H3 Lys9 and H3 Lys27 causes

A

repression of transcription

CMB2001 (21 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions