Question

Define protein-primed DNA replication.

Explain the general process of reverse transcription and integration. Explain the role of tRNA in retrovirus genome replication, the enzymatic activities of the reverse transcriptase enzyme, and the function of the integrase enzyme.

Answer 1

Answer- Protein-primed replication constitutes a generalized mechanism to initiate DNA or RNA synthesis in a number of linear genomes of viruses, linear plasmids and mobile elements. By this mechanism, a so-called terminal protein (TP) primes replication and becomes covalently linked to the genome ends.

general process of reverse transcription and integration-

*When a mature HIV-1 virion infects a susceptible target cell, interactions of the envelope glycoprotein with the coreceptors on the surface of the cell brings about a fusion of the membranes of the host cell and the virion. This fusion introduces the contents of the virion into the cytoplasm of the cell, setting the stage for reverse transcription. There are complexities to the early events that accompany reverse transcription in an infected cell.the mechanics of the conversion of the single-stranded RNA genome found in the virion into the linear double-stranded DNA that is the substrate for the integration process.

The function of the integrase enzyme-

Integrase is the viral enzyme that catalyzes the integration of virally derived DNA into the host cell DNA in the nucleus, forming a provirus that can be activated to produce viral proteins.