DNA Length and Cationic Cofactor Dependent Strand Transfer Activity of HIV-1 Integrase

HIV-1 integrase (IN)-catalyzed strand transfer is a divalent cationic cofactor dependent reaction which involves IN-DNA interaction. In this work, viral DNA substrates with different lengths were used. The strand transfer activity of IN with these DNA substrates in the presence of Mn²⁺ and Mg²⁺ were investigated, as well as some other reaction characters related with IN-DNA interaction. It is found that the strand transfer activity is both divalent cation and viral DNA length dependent. The reaction conditions for the wild type IN are stricter than those of soluble mutant IN. Moreover, IN significantly prefers E strand over A strand as the target strand, and both the recessed and blunt end viral DNA have similar strand transfer activity in the presence of either metal ion. This work provides valuable insight for the understanding of IN-DNA interaction and will be helpful in the anti-IN drug development.