Chromatin Structure Part 1 Flashcards
1
Q
Levels of transcriptional regulation
A
- Fine control
- Course or Global Control
2
Q
fine control
A
- interaction with cis-acting DNA sequences (promoters and enhancers) with RNA polymerase and transcription factors
3
Q
course (global) control
A
- 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
Q
The epigenome
A
- all of DNA and modifications
- and associated proteins
5
Q
genome
A
- totality of DNA
6
Q
fundamental fiber of both metaphase chromosomes and interphase chromatin
A
- 30 nm fiber
- organized into topologically isolated loop domains
7
Q
H1
A
- compact chromatin at this level facilitation formation of 30 nm fiber
8
Q
DNA in 10-nm fiber
A
- some DNA is accessible
9
Q
DNA in 30-nm fiber
A
- most of the DNA is folded into the interior
- NOT ACCESSIBLE to RNA pol and transcription factors
10
Q
loop domains
A
- located within loop arrangment
11
Q
nucleosomes
A
- histones with DNA wrapped around them
12
Q
basic nucleosome
A
- histone octomer
- 2 of each molecule
- H3 and H4
- H2A and H2B
13
Q
histone evolution
A
- 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
Q
non allelic variants
A
- histones encoded by different genes in genome
15
Q
multigene families:
A
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
