TMC 8

Question 1

Describe the DNA sequence and structure of a strong E. coli promoter.

Answer 1

• A consensus DNA seq. found –> TATAAT – 10 bases upstream from start point of transcription (+1) – called the TATA box
• A 2nd consensus seq. found –> TTGACA – at -35 region – called the -35 box
• A gap of 17-19 bp between the -35 box and the TATA box was also found

Question 2

E. coli RNA pol. and sigma factor 90

Answer 2

E.coli - one RNA pol – core RNA pol. - has 5 subunits
– Core RNA pol. very inefficient at recognising promters in Ecoli genes thus doesnt transcribe RNA effectively
– E. coli also has a protein called sigma factor 70
– sig. fac. 70 together w/ core RNA pol. recognise promoters specifically - thus effective transcription of RNA
– E. coli core RNA pol + sig. fac. 70 protein together called –> RNA Polymerase holoenzyme

Question 3

what is the