Question

Which statement is FALSE? During integration of the retrovirus linear DNA into the host genome to form the provirus, the 5-recessed ends of LTRs are linked to staggered 3 ends of the target DNA. Integrase catalyzes all stages of retrovirus linear ds DNA integration into the host genome. Two bases from each of the 5 protruding ends of retrovirus LTRs are deleted during integration into provirus. During integration of the retrovirus linear DNA into the host genome to form the provirus, the 3-recessed ends of the LTRs are linked to staggered 5 ends of the target DNA.

1) During integration of the retrovirus linear DNA into the host genome to form the provirus, the 5-recessed ends of LTRs are linked to staggered 3 ends of the target DNA.
2) Integrase catalyzes all stages of retrovirus linear ds DNA integration into the host genome.
3) Two bases from each of the 5 protruding ends of retrovirus LTRs are deleted during integration into provirus.
4) During integration of the retrovirus linear DNA into the host genome to form the provirus, the 3-recessed ends of the LTRs are linked to staggered 5 ends of the target DNA.

Answer 1

The false statement is that the 3-recessed ends of the LTRs are linked to staggered 5 ends of the target DNA; it is actually the 5' protruding ends of the retroviral LTRs that are linked to the staggered 3' ends of the host DNA during retroviral integration.

Step-by-step explanation:

The statement that is FALSE in the context of retroviral integration into the host genome is: "During integration of the retrovirus linear DNA into the host genome to form the provirus, the 3-recessed ends of the LTRs are linked to staggered 5 ends of the target DNA."

This statement is incorrect because it is the 3-recessed ends of the LTRs that are linked to the staggered 5' ends of the target DNA during retroviral integration. The integrase enzyme indeed catalyzes the integration of viral DNA into the host genome, but it is not accurate to say it catalyzes all stages, as reverse transcriptase and other proteins are also essential for various stages of the retroviral life cycle.

During retroviral integration, integrase facilitates the joining of viral and host DNA by making staggered cuts in the target DNA. It is the 5' protruding ends of the retroviral LTRs that are processed and joined to the staggered 3' ends of the host DNA, not the 5-recessed ends as one statement incorrectly suggests. After integration, the host's cellular machinery repairs the gaps, resulting in a provirus seamlessly integrated into the host's genome.