Altered-specificity mutants of the HIV Rev arginine-rich motif-RRE IIB interaction.

Arginine-rich motifs (ARMs) bind RNA structures with high affinity and specificity, and the human immunodeficiency virus (HIV) exploits ARM-RNA interactions to regulate its lifecycle. The expression of HIV structural genes relies on recognition between the ARM of its Rev protein and its primary binding site, an internal loop in the viral RNA, the Rev-response element region IIB (IIB). Many functional variants of the Rev ARM-IIB interaction have been discovered, yet how easily it can evolve new specificities is poorly explored.