Quiz 4 review

Question 1

In E. coli, the RNA polymerase core enzyme is made up of:

Answer 1

α2ββ’ω

Question 2

Sigma factor always disassociates from the holoenzyme enzymes before elongation can proceed.

Answer 2

False

Question 3

Mutations in sigma factor’s DNA binding domain can change its affinity, positively or negatively, for the hexameric promoter elements.

Answer 3

True

Question 4

In eukaryotes, RNA polymerase is responsible for locating and binding to the core promoter without aid from other factors.

Answer 4

False

Question 5

Rho acts in cis to regulate termination.

Answer 5

False

Question 6

TBP must bind to a TATA-box to regulate transcription.

Answer 6

False

Question 7

Typically, the assembly factors bind to their cis targets before TBP can bind.

Answer 7

True

Question 8

Which statement is correct about sigma factors?

Answer 8

All sigma factors associate with the same set of core enzymes.

Question 9

What three cis elements represent upstream elements in a RNA pol III type 3 promoter?

Answer 9

Oct, PSE, TATA-box

Question 10

An enhancer can reside many kilobases away or right next to a promoter that it regulates.

Answer 10

True

Question 11

Select the phrase that best describes the role of TFIIIA.

Answer 11

TFIIIA is an assembly factor involved in RNA polymerase III transcription of a Type 1 promoter.

Question 12

In abortive initiation, RNA polymerase fails to exit the promoter, however nascent RNA is transcribed. Typically, how much RNA is transcribed during an abortive initiation?

Answer 12

approx. 9 bases

Question 13

Intrinsic termination relies on cis acting factors.

Answer 13

True

Question 14

In E. coli RNA polymerase is most often found associated with DNA

Answer 14

True

Question 15

What basal transcription factor is involved with both transcription and DNA repair?

Answer 15

TFIIH

Question 16

For an RNA polymerase III type 1 promoter, TFIIIA interacts directly with RNA polymerase. In other words, there is direct physical contact between RNA pol III and TFIIIA.

Answer 16

False

Question 17

What trans-acting factor binds to the upstream promoter element in a RNA polymerase I promoter target?

Answer 17

UBF1

Question 18

The startpoint in a bacterial promotor is almost always a __________.

Answer 18

purine

Question 19

In E. coli why is a perfect match to a promoter consensus sequence often less efficient at inducing transcription than a promoter with minor deviations from the consensus?

Answer 19

a perfect match to a promoter consensus sequence can cause the holoenzyme to bind so tightly that it is unable to exit the promoter region and enter into elongation.

Question 20

Why is TBP called the Universal Factor?

Answer 20

TBP is universally required by RNA pol I, II and III for transcription.

Question 21

Similar to replication, transcription is almost always bidirectional.

Answer 21

False

Question 22

The consensus sequence of the Pribnow box is _________.

Answer 22

TATAAT

Question 23

What are the three ways in which RNA polymerase “scans” the bacterial genome?

Answer 23

Sliding, Intrasegmental transfer, Intersegmental transfer

Question 24

Approximately what proportion of the total RNA in the cytoplasm of a eukaryotic cell is protein coding mRNA?

Answer 24

5%

Question 25

Enhancers frequently interact with promoters through protein-protein connections.

Answer 25

True