Question

What does the enzyme reverse transcriptase do? How might that be useful for studying RNA viruses like SARS-CoV-2?

Answer 1

Enzyme Reverse Transcriptase is responsible for conversion of RNA to DNA (Reverse Transcription). RNA viruses have this enzyme by which they incorporate their genetic information in host genome.

SARS-Cov-2 is the strain of coronavirus that is causing COVID-19 pandemic. It has single stranded RNA genome. It uses Reverse Transcriptase to incorporate it's genetic information in the host genome and proliferate thereafter.

So what we can do with this reverse transcriptase?

It can be used in early diagnosis of COVID-19 by following a diagnostic technique called Real Time - Polymerase Chain Reaction (RT-PCR). How?

Suspected person's specimen can be collected. It can be treated with chemical substances that would digest all other macromolecules like protein, fat, carbohydrates leaving genetic material only. This extracted general material is person's own DNA along with Virus RNA. Here, we can treat it with Reverse Transcriptase to convert the RNA into DNA. Then a shortcomplimentary strand to specific part of transcibed DNA is also provided. If suspected person has viral DNA, complementary strand would bind to it. If placed in RT-PCR machine, it would provide the correct environment for this DNA to replicate. It is amplified enough to get detected. This is how we use Reverse Transcriptase in diagnosis of SARS-COv-2. RNA cannot be amplified for detection as it cannot replicate. Therefore, Reverse Transcriptase is useful.