RNA Part 2 Flashcards
Key differences in transcription between eukaryotes and prokaryotes
Genes and their spacing?
Eukaryotes typically have more genes that are spaced further apart
Key differences in transcription between eukaryotes and prokaryotes
RNA pol?
Eukaryotes have 4 RNA polymerases
Prokaryotes have 1
Key differences in transcription between eukaryotes and prokaryotes
What do eukaryotes have the prokaryotes dont?
Nucleus
How is DNA in eukaryotes packaged?
Into chromatin
In eukaryotes, _ are exported from the nucleus prior to translation
Transcripts
What are the 3 RNA polymerases
RNA pol I
RNA pol II
RNA pol III
RNA pol I responsibility
Recruits the ribosome and rRNA
rRNA genes except 5s
RNA pol II responsibility?
Transcribes protein-coding genes and a variety of noncoding RNAs
RNA pol III responsibility
tRNAs, some snRNAs, 5s rRNA
Most eukaryotes have multiple if not many, _ copies of rDNA genes
tandem
RNA pol II recruitment and activation
What is a preinitiation complex (PIC) ?
A number of general transcription factors cooperate to form the PIC
What does the PIC do?
PIC recruits additional transcription factors and RNA pol II
How do you enable elongation?
A kinase phosphorylates RNA pol II and other proteins to enable elongation
What does the architecture of RNA pol III recruitment and activation depend on?
What does that mean?
Depends on the promoter type.
Different promoters regulate different genes
What is RNA pol II regulated by?
RNA pol II is regulated at multiple steps by carboxyl-terminal domain (CTD) posttranslational modification
How many models did we go over for how RNA pol II terminates
2
First model of RNA pol II termination?
An exonuclease causes RNA pol II to dissociate
Second model of how RNA pol II terminates?
The cleavage of mRNA causes a conformational change in RNA pol II