Histones and Nucleosomes

DNA is wound _________ times around histones

1.67

The packaging ration of the 30nm fiber and above is ~_________

1000

The ____________ (beads on a string) is comprised of the nucleosome

10nm fiber

If you do a limit digest (prolonged) of the nucleosome, you get it down to ______ bp

146

Nucleosomes contain _____ copies of each of the four histones

2

If you do a mild (average) digest of the nucleosome, you get ______ bp

200

The nucleos contains ~ ______ bp

200

To get a protein to go to the nucleus _________ amino acids must be basic

3/5

The ________ is formed from a coil of the 10nm fiber

30nm fiber

The packaging ratio of the 30nm fiber is ~_____

40

The packaging ratio of the 10nm fiber is ~____

6

Chromatin is composed of _____________ Protein, _____________ DNA, and ______________ RNA

60% 30% 10%

The linker DNA between nucleosomes is ________ bp

8-114

________ is involved in assembly of nucleosomes in both laging and leading strands

ASF1

__________ is a critical protein in nucleosome assembly and binds to H3/H4 tetramer

CAF1

Both _______ and ________ are a part of replication dependent nucleosome assembly

CAF1; ASF1

__________ recruit the pre-initiation complex and acts on the promoter

Enhancers

________ goes in front of the polymerase and release the H2A/H2B dimer (takes the cap off), disassembling the nucleosome

FACT

True or False: Histones in the nucleosome have tails

False

True or False: The 30nm fiber exists in archae

False (because there is not H1 for the 10nm fiber to wrap around)

True or False: the 30nm fiber exhibits a solenoid structure

False; it is a zig-zag 2 start helix

True or False: Chemical modifications on the histone tails are heritable

False; only chemical modifications of the DNA are

True or False: Archae have histone H1

False; thus they have no 30nm fiber

The 30nm requires the typical nucleosomal histones plus ______

H1

_______ is critical to transfer from 10nm fibers to 30nm fibers

H1

H___/H____ is a dimer

H2A/H2B

In forming the full nucleosome, H3 makes contact with ______

H3

The two most highly conserved proteins in evolution are _______ and ______

H3 and H4

Histone _________ more directly affect transcription

H3s

Histone _________ are more associted with nucleosome assembly

H4s

Histones are acetylated/deactylated by _____________/___________

HATs/HDACs

Instead of using CAF1, H3.3 uses _________ in nucleosome assembly

HIRA

____________ of the protein part of chromatin is comprised of histones

Half

_______________ replaces histone H3 in non-differentiating cells after transcription

Histone 3.3

_________________ are sequences in the genes that attract proteins that limit neighboring genes from also being activated

Insulators

Histone are methylated by _____________

Methylases

____________ is a longer term modification histone modification

Methylation

_________________ cuts at the linker DNA between nucleosomes

Micrococcal nuclease

The ______ terminals of histone tails are modified

N-

________ and _______ proteins are required to assist in the assembly of nucleosomes

Nucleoplasmin; N1

CAF1 is recruited to the replication fork by ________

PCNA

___________ and ____________ are short term modifications of histones

Phosphorylation and Acetylation

What is the size of RNA polymerase relative to the nucleosome?

RNA polymerase is larger

Why don't archae have histone tails?

Their DNA is always open in the 10nm fiber

True or False: RNA polymerase displaces histones during transcription

True

Nucleoplasmin and N1 proteins are ___________

acidic

Acetylation is generally associated with gene ______________

activation

H3.3 is used _________ repair

after

H3 and H4 first appeared in ____________

archae

Acetylation during replication occurs on histones ___________ they are incorporated into nucleosomes

before

The H2A/H2B dimer forms a _______

cap

The histone ____________ is a helix-loop-helix-loop

fold

Replication-independent nucleosome assembly utilizes a ______________

histone H3 variant

Phosphorylation is mediated by ______________

kinases

H1 binds to the ________

linker DNA

The ___________ is the fundamental unit of structure for the chromosome

nucleosome

Nucleosomes are __________ when transcription passes through a gene

reorganized