The gene for HIV-1 protease is located from positions 1799 - 2095 of the HIV reference genome, and is initially translated as part of the gag-pro polypeptide.
To begin the post-translational maturation process, the protease must cleave the peptide bonds between itself and the upstream (p6 gag-pol transframe peptide) and downstream (p51 reverse transcriptase) polypeptides. It is not known what regulates or triggers this self-processing reaction. Since HIV-1 protease normally acts as a homodimer, it is possible to speculate that two polyproteins may interact via dimerization of the protease domains, leading to excision of the protease dimer, which leads to proteolytic processing at the other polyprotein boundaries.
Dunn, Goodenow, Gustchina & Wlodawer. 2002. Genome Biology. Protein Family Review: Retroviral proteases.
Los Alamos National Lab. Accessed 2014-02-17. HIV-1 Gene Map