Final answer:
The prototype nucleoside reverse transcriptase inhibitor used for HIV treatment is azidothymidine (AZT), which competitively inhibits the reverse transcriptase enzyme, essential for viral replication.
Step-by-step explanation:
The prototype nucleoside reverse transcriptase inhibitor commonly used in the treatment of HIV is azidothymidine (also known as zidovudine or AZT). Nucleoside reverse transcriptase inhibitors, or NRTIs, and nucleotide reverse transcriptase inhibitors are key components in anti-retroviral therapy (ART) for the treatment of AIDS. They function by competitively inhibiting the reverse transcriptase enzyme, which is necessary for the conversion of viral RNA into DNA - a critical step in the viral replication process. Among other NRTIs, AZT was the first drug approved to treat HIV and remains a cornerstone in HIV therapy.