Reverse Transcription

Question 1

What type of polymerase carries out transcription from DNA to RNA?

Answer 1

DNA-dependent RNA polymerases
(Pol II etc)

Question 2

What does Reverse Transcriptase do?

Answer 2

Reverse transcription of RNA to cDNA:
* Use RNA as a template to synthesise a complementary DNA strand
* RNA strand is degraded
* Complementary DNA strand is then synthesised

Question 3

How does the HIV virus use a Reverse Transcriptase (RT) to propogate in host cells?

Answer 3

1. HIV virus infects cells
2. Viral RNA is reverse transcribed into DNA
3. DNA integrates into host genome
4. Viral genes are expressed to generate new virus

Question 4

What are some key viral proteins that the integrate HIV genome expresses?

Answer 4

• Structural proteins
• Integrase
• Reverse Transcriptase
• Protease - poly protein cleaved by HIV protease

Question 5

What drugs inhibit HIV Reverse Transcriptase?

Answer 5

Nucleoside analogue drugs AZT and 3TC

Question 6

Is telomerase a reverse transcriptase?

Answer 6

Yes

Question 7

What is the role of Telomerase?

Answer 7

Adds bases to ends of Eukaryotic chromosomes
(Telomeres)

Question 8

What does the RNA in Telomerase consist of?

Answer 8

1.5 copies of the Cn An sequence

This RNA acts as a template for synthesis of Tn Gn strand by reverse transcriptase

Question 9

What are the uses of cDNA?

Answer 9

• Amplify selected genes by PCR to detect or quantify gene expression
• Insert cDNA into vector and clone to generate a “cDNA library” representing all genes expressed in cell at this time (mRNA)
• Next generation sequencing to identify expressed genes: RNA Seq