HIV integrase is a crucial enzyme within the retrovirus family, responsible for integrating HIV's reverse-transcribed DNA into the host cell genome. The enzyme consists of three main domains: N-terminal domain, catalytic core domain, and C-terminal domain, primarily localized to the host cell nucleus. By catalyzing the covalent connection between the retroviral DNA and host DNA, integrase plays a vital role in the HIV replication cycle, making it an important target for antiretroviral therapy. The integrase gene is specifically expressed in HIV, and its activity and affinity are regulated by host cell factors. Gene mutations can affect its catalytic activity, leading to the development of drug resistance.