Which enzymes are encoded by the HIV pol gene?

Which enzymes are encoded by the HIV pol gene?

• A. Reverse Transcriptase, Integrase, Protease
• B. DNA Polymerase, RNA Polymerase, Ligase
• C. Helicase, Topoisomerase, Nuclease
• D. Methyltransferase, Kinase, Phosphatase

Answer: (A)

The main concept is that the HIV pol gene encodes the viral enzymes needed to replicate its genome and produce mature virions: reverse transcriptase, integrase, and protease. Reverse transcriptase copies the viral RNA genome into DNA, a critical step because the virus is an RNA virus that must integrate its genome into the host. Integrase then inserts this viral DNA into the host cell’s genome, establishing a provirus that can be transcribed and translated by the host machinery. Protease cleaves the long viral polyproteins into the individual, functional viral proteins, which is essential for assembling infectious virus particles. The other enzyme sets don’t fit because they are general cellular or non-HIV-specific enzymes. DNA polymerase, RNA polymerase, and ligase are typical host-cell enzymes involved in DNA replication and transcription, not the viral replication enzymes encoded by the HIV pol gene. Helicase, topoisomerase, and nuclease are nucleic-acid-processing enzymes that aren’t the trio produced by HIV’s pol gene. Methyltransferase, kinase, and phosphatase describe other enzyme activities that aren’t the characteristic products of the HIV pol gene.

The main concept is that the HIV pol gene encodes the viral enzymes needed to replicate its genome and produce mature virions: reverse transcriptase, integrase, and protease. Reverse transcriptase copies the viral RNA genome into DNA, a critical step because the virus is an RNA virus that must integrate its genome into the host. Integrase then inserts this viral DNA into the host cell’s genome, establishing a provirus that can be transcribed and translated by the host machinery. Protease cleaves the long viral polyproteins into the individual, functional viral proteins, which is essential for assembling infectious virus particles.

The other enzyme sets don’t fit because they are general cellular or non-HIV-specific enzymes. DNA polymerase, RNA polymerase, and ligase are typical host-cell enzymes involved in DNA replication and transcription, not the viral replication enzymes encoded by the HIV pol gene. Helicase, topoisomerase, and nuclease are nucleic-acid-processing enzymes that aren’t the trio produced by HIV’s pol gene. Methyltransferase, kinase, and phosphatase describe other enzyme activities that aren’t the characteristic products of the HIV pol gene.