Reverse transcriptase
Reverse transcriptase (RT) is an enzyme that controls the replication of the genetic material of HIV and other retroviruses. The enzyme has two enzymatic functions. Firstly it acts as a polymerase where it transcribes the single-stranded RNA genome into single-stranded DNA and subsequently builds a complementary strand of DNA. This provides a DNA double helix which can be integrated in the host cell's chromosome. Secondly it has ribonuclease H (Rnase H) activity as it degrades the RNA strand of RNA-DNA intermediate that forms during viral DNA synthesis.