5.4 Regulation of Transcription Part 2 Flashcards
What is critical for efficient and correct transcription?
ability of promoters to be recognized by RNA polymerase
What are consensus sites?
points on DNA around the transcriptional start sites that are conserved
What are two examples of a consensus site?
Pribnow box
-35
Where is the Pribnow box found?
-10 (10 nucleotides upstream from the transcription initiation site
What are cis-acting elements?
sites located on the same strand near the region to be transcribed
What are the proteins that bind to cis-acting elements?
trans-acting factors
What are strong promoters?
promotors that elicit DNA binding every few seconds
What are weak promoters?
promoters that elicit DNA binding less
What do the other subunits of the RNA Polymerase do?
recognize different promoter sequences in different environmental conditions such as extreme temp and nutrient deficiency
How are new nucleotides linked to the growing chain?
phosphodiester bond
Which direction does RNA synthesis occur?
5’-3’
As transcription progress what happens?
sigma subunit dissociates and the core enzymes continues chain elongation
Can RNA polymerase perform proofreading?
yes
How long is the termination sequence to terminate RNA polymerase activity?
about 20 nucleotides long
What happens once the termination sequence is transcribed?
it forms back on itself to form a hairpin secondary structure
