Basal Transcription- Lecture 23

Question 1

Name the three kinds of RNA polymerase and their functions.

Answer 1

RNA pol I (transcribes mostly rRNA genes)
RNA pol II (transcribes protein-coding genes)
RNA pol III (transcribes mostly tRNA genes)

Question 2

What is a core promoter?

Answer 2

a DNA sequence located in the immediate vicinity of the +1 site at which RNA pol II binds (directed by numerous other protein factors)

Question 3

______ is a consensus sequence found about 25-30 base pairs up stream from the core promoter and is bound by ______.

Answer 3

TATA box

TBP (a subunit of TFIID)

Question 4

What composes a TFIID complex?

Answer 4

TBP and 15 TAFs

Question 5

What are the kinds of TFIIDs that form the greater complex?

Answer 5

A, B, D, E, F, H

Question 6

What composes a pre-initiation complex?

Answer 6

various TFIIDs and a mediator

Question 7

What are the four steps of transcription?

Answer 7

formation of the pre-initiation complex, initiation, elongation, and termination

Question 8

What event initiates transcription?

Answer 8

hyperphosphorylation of the carboxy-terminal domain of the largest RNA pol II subunit (consisting of multiple repeats of a short, serine rich sequence) by TFIIH (a protein kinase)

Question 9

What is the first nucleotide in the pre-mRNA?

Answer 9

a nucleoside 5’-triphosphate (which will have a cap shortly after transcription initiation)

Question 10

What does the elongation phase of translation entail?

Answer 10

helicase unwinds the double stranded DNA template ahead of the elongating transcription complex and topoisomerase relieves the tension creased by the unwinding

Question 11

_____ is the rate at which re-initiation (the binding of another RNA pol II complex to the promoter region after one leaves the promoter region) occurs.

Answer 11

The rate of transcription initiation

Question 12

What is the torpedo model?

Answer 12

when RNA pol II transcribes past a polyadenylation signal and the nascent RNA is cleaved to allow poly(A) addition, generating a new 5’ end which is unprotected and can be bound to 5’ endonuclease that begins degrading the the RNA in the 5’ to 3’ direction until it encounters the elongatign RNA pol II and causes a conformational change resulting in the release of RNA pol II from the DNA template

Question 13

The recycling of _____ to its _____ state by _____ is important to the repeat round of transcription.

Answer 13

RNA pol II
hypophosphorylated
CTD phosphatase

Question 14

Promoter elements and promoter-proximal elements are ______ elements that are bound by constitutively-acting ____ elements.

Answer 14

cis

trans