What is reverse transcriptase and how does it work?

Reverse transcriptase is an enzyme (or protein) that the HIV virus carries to make a DNA copy of itself once it gets inside a cell. This DNA copy can then get inside the cell nucleus and become incorporated into the human cell DNA. The enzyme takes building blocks (nucleosides) from the existing cell to make a chain of nucleosides which then become DNA. Drugs like AZT or 3TC are nucleoside analogues or decoys which get put into the lengthening DNA chain. Once they are placed in the DNA, the process is aborted, and the virus can not copy itself. These drugs are called chain terminators. Drugs like nevirapine (Virammune) or efavirenz (sustiva) are true reverse transcriptase inhibitors in that they block the function of the enzyme, so the DNA chain also cannot be produced. MH