Lecture 5 DNA Transcription

Question 1

How many RNA polymerases do prokaryotes have vs eukaryotes?

Answer 1

prokaryotes have 1 eukaryotes have 3

Question 2

What is upstream?

Answer 2

prior to start point

Question 3

What is the TATA box?

Answer 3

TATA box is a non coding DNA sequence found upstream of gene transcription site

Question 4

transcription initiation in prokaryotes vs eukaryotes?

Answer 4

prokaryotes have sigma factor eukaryotes have several transcription factors

Question 5

What is the function of sigma70?

Answer 5

to recognize the promoter (promoter sequence commonly known as “consensus sequence”) and secure RNA polymerase binding

Question 6

what is the function of sigma 1?

Answer 6

prevents premature dissociation of RNA polymerase binds next to -10 site

Question 7

What is the function os sigma 2?

Answer 7

Separates dsDNA and helps stabilize ssDNA

Question 8

What is the 3.2 region?

Answer 8

a loop between sigma 3 and 4 helps position the incoming rNTPS on RNA polymerases active site

Question 9

What is INR?

Answer 9

Initiator element located -2+4

Question 10

What is BRE?

Answer 10

TFIIB recognition element located upstream of the TATA box around -30-40

Question 11

Where does RNA polymerase begin transcription?

Answer 11

At position +1

Question 12

How many transcription factors form with RNA polymerase the eukaryotic initiation complex?

Answer 12

6

Question 13

How many classes of transcription terminators are available for the prokaryotic cell?

Answer 13

2 - Intrinsic and enzymatic

Question 14

what does the term abortive initiation refer to?

Answer 14

Termination of transcription, after RNA polymerase complex synthesised a few nucleotides