Human immunodeficiency virus type 1 reverse transcriptase; Hepatitis B virus polymerase (HIV-1 RT; HBV polymerase)

**HIV-1 reverse transcriptase** is a **heterodimeric enzyme** composed of p66 and p51 subunits, with the active site for DNA polymerase and RNase H in the p66 subunit[1][5][7]. It is essential for the replication of HIV-1, enabling conversion of the viral single-stranded RNA genome into double-stranded DNA, which is then integrated into the host genome[2][9]. RT is the target of two main drug classes, NRTIs and NNRTIs, which inhibit the enzyme by distinct mechanisms[2][4][8]. Drug resistance mutations in RT are common and can severely limit treatment options[8][7]. **Hepatitis B virus polymerase** is a multifunctional enzyme responsible for viral DNA synthesis and replication of HBV. It shares similar mechanistic features with HIV-1 RT, making NRTI analogs effective for both viruses[2]. **Note**: The target "HIV-1 reverse transcriptase and hepatitis B polymerase" is commonly referenced in drug development because nucleos(t)ide analogues (e.g., tenofovir, lamivudine, emtricitabine) inhibit both enzymes and are used for both HIV and HBV infections. However, for molecular biology or drug screening, these targets should be addressed individually to avoid confusion and ensure precise data mapping.

Other names

HIV-1 RTRTReverse transcriptaseHBV polymeraseDNA polymeraseP protein (for HBV)

NRTIs: Act as chain terminators, incorporated into DNA/RNA during synthesis, halting elongation NNRTIs: Bind to allosteric site (NNRTI binding pocket) of HIV-1 RT, inhibit polymerase activity non-competitively RNase H inhibitors (HIV-1): Inhibit RNA degradation during replication