Chromatin Structure Part 1 Flashcards Preview

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Flashcards in Chromatin Structure Part 1 Deck (15):
1

Levels of transcriptional regulation

- Fine control
- Course or Global Control

2

fine control

- interaction with cis-acting DNA sequences (promoters and enhancers) with RNA polymerase and transcription factors

3

course (global) control

- changes in structure of chromatin to prevent or enable access of RNA polymerase and transcription factors
- access is key word
- DNA must be accessible.

4

The epigenome

- all of DNA and modifications
- and associated proteins

5

genome

- totality of DNA

6

fundamental fiber of both metaphase chromosomes and interphase chromatin

- 30 nm fiber
- organized into topologically isolated loop domains

7

H1

- compact chromatin at this level facilitation formation of 30 nm fiber

8

DNA in 10-nm fiber

- some DNA is accessible

9

DNA in 30-nm fiber

- most of the DNA is folded into the interior
- NOT ACCESSIBLE to RNA pol and transcription factors

10

loop domains

- located within loop arrangment

11

nucleosomes

- histones with DNA wrapped around them

12

basic nucleosome

- histone octomer
- 2 of each molecule
- H3 and H4
- H2A and H2B

13

histone evolution

- high degree of conservation in histones
- reflect ability to be in all cells and compact DNA
- different degrees of evolutionary conservation of histone sequences.

14

non allelic variants

- histones encoded by different genes in genome

15

multigene families:

members have different DNA sequences that can lead to

- same protein
- proteins with different sequences but same size
- proteins with different sequences and different size