Chromatin Structure

Question 1

histone proteins

Answer 1

H1, H2A, H2B, H3, H4

Question 2

H1

Answer 2

linker protein

Question 3

non-histone proteins

Answer 3

proteins that regulate transcription, telomere stability, mitotic condensation, etc.

Question 4

chromatin

Answer 4

DNA + proteins

Question 5

nucleasome

Answer 5

DNA wrapped around histone core proteins

Question 6

chromatosome

Answer 6

nucleosome + H1 histone

Question 7

nuclease

Answer 7

digests linker DNA

Question 8

mechanisms of changes in chromatin structure

Answer 8

ATP-driven chromatin remodeling machines, covalent modifications of histone tails, histone variants

Question 9

ATP-driven chromatin remodeling

Answer 9

pushes nucleosome so some parts of DNA will become less compacted which exposes regulatory sequences for TF binding –> opens up DNA (euchromatin)

Question 10

examples of ATP-dependent mechanisms

Answer 10

removing H2A-H2B dimers from nucleosome or replacing H2A-H2B dimer with a variant

Question 11

methylation can _

Answer 11

activate or repress but usually represses

Question 12

acetylation can _

Answer 12

only activate

Question 13

heterochromatin is often associated with _

Answer 13

tri-methylation (H3K9)

Question 14

consequences of acetylation

Answer 14

neutralizes plus charge on lysines, eliminates interaction with DNA phosphate groups, reduces affinity of entire nucleosome for DNA to open chromatin

Question 15

HDAC inhibitors

Answer 15

inhibit histone deacetylases and are possible source of cancer treatment

Question 16

What class of enzymes are required for the inheritance of DNA methylation patterns?

Answer 16

maintenance methyltransferases

Question 17

barrier sequences

Answer 17

block propagation of heterochromatin into euchromatin