T.10 La RNA Pol III

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How many subunits does RNA Pol III consist of?

19

17 (correct)

20

15

What is the main function of RNA Pol III?

To transcribe a limited number of genes (correct)

To translate mRNAs

To catalyze protein synthesis

To transcribe all genes

What is the main difference between genes transcribed by RNA Pol III and other polymerases?

Sequence of the gene

Size of the gene

Type of RNA produced (correct)

Function of the gene product

What is the name of the additional trimer found in RNA Pol III?

C82/C34/C31 Signup and view all the answers

What is unique about the promoters of genes type I and II?

They are located within the sequence to be transcribed. Signup and view all the answers

What is the role of TFIIIA in the formation of the initiation complex?

It binds to the C box and the A box. Signup and view all the answers

What is common to all three types of promoters?

The presence of TBP. Signup and view all the answers

What is the difference between TFIIIB-1 and TFIIIB-2?

TFIIIB-1 is found in genes type I, while TFIIIB-2 is found in genes type II. Signup and view all the answers

What is the role of BRF1 in the formation of the initiation complex?

It is a subunit of TFIIIB. Signup and view all the answers

What is the significance of the nucleosome in genes type I?

It enhances the transcription of the gene. Signup and view all the answers

What is the function of SNAPc?

It binds to the TBP. Signup and view all the answers

What is the difference between the initiation complex of genes type I and II?

The RNA Pol III is situated differently. Signup and view all the answers

What is the role of TFIIIC in the formation of the initiation complex?

It binds to the A box and the B box. Signup and view all the answers

What is the composition of SNAPc?

It is composed of 5 subunits, including SNAPc190. Signup and view all the answers

In which type of cells is the transcription of RNA Pol III not required to be very high?

Retinal cells Signup and view all the answers

What is the effect of retinoblastoma on the transcription of RNA Pol III?

It blocks the complex TFIIIB partially Signup and view all the answers

What is the result of a mutation in the retinoblastoma gene?

An increase in cell growth Signup and view all the answers

What is the function of the heterotrimer C82/C34/C31 in RNA Pol III?

It allows the RNA Pol III to rapidly terminate and reinitiate transcription Signup and view all the answers

What is the characteristic of RNA Pol I that allows it to overcome transcriptional pauses?

It has a permanent system to solve transcriptional pauses Signup and view all the answers

What is the difference between the RNA Pol I and RNA Pol II in terms of transcriptional pauses?

RNA Pol II needs the help of external factors to overcome transcriptional pauses Signup and view all the answers

What is the result of a mutation in the retinoblastoma gene in terms of cell growth?

An increase in cell growth Signup and view all the answers

What is the function of the retinoblastoma protein in the regulation of RNA Pol III transcription?

It blocks the transcription of RNA Pol III partially Signup and view all the answers

What is the name of the protein that regulates the transcription of the 5S rRNA gene?

TFIIIA Signup and view all the answers

What is the function of the zinc fingers in the TFIIIA protein?

To recognize specific DNA sequences Signup and view all the answers

What happens to the TFIIIA protein when there is an excess of 5S rRNA?

It forms a complex with the excess 5S rRNA, blocking its activity Signup and view all the answers

What is the name of the mechanism by which the 5S rRNA gene is regulated?

Autogenous regulation Signup and view all the answers

What is the function of the Maf1 protein in response to stress?

To inhibit the transcription of the 5S rRNA gene Signup and view all the answers

What is the effect of stress on the Maf1 protein?

It becomes dephosphorylated and moves to the nucleus Signup and view all the answers

What is the function of the retinoblastoma protein?

To suppress tumor formation Signup and view all the answers

What is the type of RNA that is transcribed by RNA polymerase III?

rRNA, tRNA, and other small RNAs Signup and view all the answers

What is the name of the complex that forms between TFIIIA and the promoter region of the 5S rRNA gene?

TFIIIA-DNA complex Signup and view all the answers

What is the function of the TFIIIB complex?

To initiate the transcription of the 5S rRNA gene Signup and view all the answers

What can be said about the complex of transcription?

It makes a loop in the DNA. Signup and view all the answers

What is the function of the heterotrimer in RNA Pol III?

It extends helices that help to maintain the DNA in place. Signup and view all the answers

Why does RNA Pol III have a 'hanging' center active?

Because it facilitates rapid termination of the RNA polymerase. Signup and view all the answers