The conserved noncoding RNA elements in viral genomes interact with proteins to regulate various events during viral replication. We report studies on the recognition mechanisms of two helical peptides, namely, a native (Rev) peptide and a lab-evolved (RSG1.2) peptide, by a highly conserved viral RNA element from the human immunodeficiency virus 1 genome. Specifically, we investigated the physical interactions between the viral RNA molecule and helical peptides by computing free energy changes on mutating key amino acid residues involved in recognition of an internal loop in the viral RNA molecule.
