FIG 5.

Ordered RNA inside the HPeV3 virion. (A) RNA density segmented from within the virion seen along an icosahedral 5-fold axis. The boxed segment of the density is enlarged in panel B. (B) Eight nucleotides fit to their corresponding density before reaching the helix-coil transition. (C) VP3 tails bridge two adjacent loops of RNA to promote efficient packaging and assembly. Small portion of the capsid VP3 sequence (amino acids Leu 16 to Arg 26) is shown to clarify the VP3-RNA network on the inner surface of the viral capsid. (D) The binding pocket for RNA on the inside of the capsid involves residues from VP1 and VP3. One RNA loop is stabilized by residues from a single VP1 chain (green) and three VP3 chains (light blue designated by ′, ′′, and ′′′).