Any enzyme that reverses the normal flow of genetic information transfer. In most organisms, the DNA template in chromosomes are used to produce mRNA (the process of transcription), which is then used as a template for protein production (the process of translation). Reverse transcriptase does the opposite in that it converts single-stranded mRNA in to more stable double-stranded DNA (sometimes called cDNA). Also known as RNA-directed DNA polymerase.
Where its found
- Reverse transcriptase is found in retroviruses, e.g. HIV, which use the enzyme to incorporate viral RNA into the host cells DNA retroviruses. Inhibition of the reverse transcriptase present in HIV is one component of anti-HIV therapy.
- Telomerase is a particular type of reverse transcriptase that stops the ends of chromosomes from 'fraying' (see telomerase reverse transcriptase (TERT))
- Reverse transcriptase is used in biomolecular research to convert more labile mRNA molecules into more DNA. DNA is more stable and also allows the use of techniques such as polymerase chain reaction which work on DNA and not RNA.