The protease from the human immunodeficiency virus (HIV) is a target of the drugs used to treat HIV/AIDS. The protease has a mechanism similar to that of renin, described in Problem 44, except that renin consists of a single protein with two catalytic Asp residues, whereas the HIV protease consists of two identical subunits, each of which contributes an Asp residue. Is this an example of convergent or divergent evolution
