Skip to main content
. 2021 Sep 8;13(9):1788. doi: 10.3390/v13091788

Figure 1.

Figure 1

RNA packaging signals (a) MS2 bacteriophage encodes a coat protein (CP) that binds to a 19-nucleotide stem loop structure, known as TR. Secondary structure model of the TR stem loop and three-dimensional structure of the coat protein-TR interaction; (PDB: 1AQ3) (b) MS2 bacteriophage genome is encapsidated through cooperative interactions between coat protein that are bound to a high affinity binding site (TR) and multiple low affinity binding sites encoded throughout the genome; (c) HIV-1 Gag recognizes the genomic RNA through a GU-rich high affinity binding site in the 5′ untranslated region (5′UTR). During assembly at the plasma membrane Gag switches its specificity from GU-rich sequences to A-rich sequences, which is proposed to favour assembly of Gag on its cognate genomic RNA.