ch 12 transcription genetics FINAL
Home > Preview
The flashcards below were created by user
on FreezingBlue Flashcards.
- "consensus" sequence
- - 2 regions appear important
- -10, -35
- Faster rate of trxn if regions are similar
RNA Polymerase (E-coli)
- 5 main sub units
- 4 catalytic
- 1 regulatory
- Alpha (x2) assembly of care enzyme
- Beta Beta'(Regulatory)- binding to DNA
- - Help w/ RNA synthesis
- Sigma - binds to -10, -35 promoter
- E-coli has several Sigma factors
E-coli has several Sigma factors
Sigma70 : used in majority of genes
Transcription bubble - elongation
- 1. Rho - independent "instrinsic"
- - more simplistic
- terminator sequences: ~40 bp GC rich followed by long run of A's
- 2. Rho-dependent
- 40-60 bp rich in C, poor in G, and rho-utilization site "Rut"
- Initiation: in general more complicated
- -diff cellular compartments
- RNA processing (gene regulation)
- DNA is organized into chromatin
- size of genome
- -genes are farther apart
- -How does RNA Pol find start codon?`
*Multiple RNA Polymerases
- RNA Pol I: ALL Rrna (NOT 5S)
- II: all mRNA, some sn RNA
- III: 5s, tRNA's
Requires assembly of General Transcription
- Factors GTF's
- -necessary for function of RNA Pol II
Hangs onto RNA Pol II
TFIIH: Acts as a helicase, opens DNA, creates txrn bubble.
1. Acts as a helicase, opens DNA, creates trxn bubble
- 2. Also PO4 the carboxyl terminal domain (CTD) on RNA Pol II,
- -causes contact with TFII B,H,E breaks
- : RNA Pol transcribes past poly A
- 2 models
- 1. "Allosteric model"
- -elongation factors release or
- -termination factors bind
- 2. "Torpedo Model"
- -exonuclease binds to 5' end of RNA
- -degrades it moving towards RNA Pol II
- -hits RNA Pol and Knocks it off
What would you like to do?
Home > Flashcards > Print Preview