genetics 4 Flashcards
what is the sense strand
- AKA coding site
- 5’ —>3’
- same as RNA sequence
what is the antisense strand
- AKA template strand
- 3’—> 5’
- reverse complement of RNA
- used as template for RNA
where does prokaryotic transition occur
cytoplasm
what is the prokaryotic transcription factor
sigma factor
describe the stages of transcription in prokaryotes
1) RNA polymerase assembles
2) RNA polymerase unwinds DNA
3) transcription begins
4) +10 nucleotides - breaks promotor interaction and elongation starts
5) sigma factor released and more elongation
6) termination signal released which destabilises polymerase interaction
7) RNA released
what is rifamycins used for
- used against mycobacterium
what is tiacumacins used for
used against c.diff
what do antibiotics do
- bind to RNA polymerase
- high rate of resistance
what is RNA polymerase II used for
- mRNA
- requires transcription factors
what is RNA polymerase III used for
- tRNA
what does the CAAT box do
site for CAAT enhancer binding proteins in eukaryotic transcription
describe the steps in eukaryotic transcription - initiation
1) TATA binding proteins bind to TATA box with D - DNA bend induced
2) B recruited to B recognition element
3) RNA polymerase II recruited with transcription factors E and H
4) H hydrolysis ATP - pry apart DNA exposing template strand
5) H phosphorylates RNA polymerase II - transcription factors B,E and H released and elongation begins
what are the steps in eukaryotic transcription - elongation
1) ribonucleotides incorporated by RNA polymerase II
2) elongation factors bind RNA polymerase and some dislodge histone dimers
3) ATP depended chromatin remodelling complexes
4) DNA topoisomerase removes superhelical tension
5) RNA processing - splicing, 5’ capping and 3’ poly adenylation
what are the steps in eukaryotic transcription - termination
1) RNA polymerase I - transcription termination factor blocks and releases RNA
2) RNA polymerase II - continues to transcribe - RA transcription cleaved
3) RNA polymerase III - 4-7 3’ uracils
what does ser5 phosphorylation do
- capping proteins bind
- cap added to 5’ end passes
