Final answer:
Transducing viruses like retroviruses use reverse transcription, mediated by the enzyme reverse transcriptase, to replicate within a host cell by integrating their genetic material into the host's genome and using its machinery to produce new virions.
Step-by-step explanation:
Transducing viruses, such as retroviruses, overcome their inability to replicate independently by carrying specific genes that encode for vital enzymes like reverse transcriptase. This enzyme allows them to reverse transcribe their RNA genome into DNA, which is then integrated into the host's genome. Retroviruses, including HIV, fall under group VI of the Baltimore classification scheme, characterized by their ssRNA genome that is transcribed to dsDNA and subsequently incorporated into the host's genetic material. The mRNA produced by this integrated viral DNA directs the host cell's machinery to synthesize viral proteins and enzymes essential for the assembly of new virions.
Host cells infected by retroviruses are tricked into producing viral components because viruses use various mechanisms, such as mimicking cellular molecules. After virus production, enveloped viruses may bud off from the host cell, while non-enveloped ones may trigger cell lysis or apoptosis. Importantly, the discovery that certain retroviruses produce unique enzymes has led to the development of antiretroviral drugs, such as reverse transcriptase inhibitors, which target these viral enzymes without harming the host cell's metabolism, demonstrating successful clinical applications in reducing viral load to undetectable levels in patients.