1H2A, H2B, H3, and H4
are responsible for folding DNA into nucleosomes. (Core Histones)
2H1
is bound to the DNA where the double helix enters and leaves the nucleosome core.
(Linker Histone)
3What forms an octamer?
H3-H4 tetramers, 2 dimers of H2A-H2B
4Stem loops contain
high GC content
5Steps for RNA synthesis
1. Initation
2. elongation
3. temination
6Requirements of RNA synthesis
template, UTP, metal ions
7Initiation
- Sigma searches for and binds to promoter sequences, initiation sites for RNA synthesis
- DNA double helix is unwound
8Elongation
Select the ribonucleoside triphosphate that corresponds to the DNA template and catalyze them formation of a phosphodiester linkage
9sigma (σ) subunit
- holoenzyme helps the polymerase locate promoter sites
- catalytic
10Strong promoters
TTGATA - TATAAT
TTGACA
11Weak promoters
CTGACG - TACTGT
TTGACA - TATAAT
12σ70 has 4 structural domains
- σ4 recognizes the -35 region, σ2 recognizes the -10 region
13σ factor release from anti-σ factor
- OMP
- Oxidative stress dephosphorylates RsbV to release σ
14The 5’ end of the primary transcript (pre-mRNA in eukaryotes) is usually
a purine
15Termination
Simplest stop signal is a segment of palindromic DNA (rho-independent)