Researchers at the University of Minnesota have recently solved the 3D structure of a protein that naturally protects people from the HIV virus. While scientists often know the chemical formula of most proteins, the 3D structure of a protein is often necessary to understand its function. This anti-HIV protein, APOBEC3G, is a “DNA binding protein” which seeks and mutates specific DNA sequences. Targets of APOBEC3G include many retroviruses, such as HIV, and retrotransposons, which are segments of DNA that can insert themselves randomly in a genome and induce mutations. Geneticists hypothesize that retrotransposons may be the remnants of ancient viruses or their evolutionary precursors. Transposons and remnants of transposons make up about 42% of the human genome.

Because an HIV viral protein, Vif, blocks APOBEC3G, HIV can replicate unchecked by the natural defense of the human immune system. Now that the structure APOBEC3G has been solved, hopefully new anti-HIV drugs may be developed which interrupt Vif from inhibiting APOBEC3G or modify APOBEC3G to resist Vif’s blocking mechanism.