FIG. 2.

Position-specific variability and accessibility in the V1V2 domain. HIV-1 reference strain HxB2 positions from 126 to 196 are shown. The most frequently occurring side chains at each position corresponding to the HxB2 numbering are labeled on the x-axis. Each bar is colored according to the mean relative accessibility of that specific side chain in the context of glycosylated (a) or nonglycosylated (b) gp140 trimer: light green for buried side chains (relative solvent accessibility <20%) and dark green for exposed side chains (relative solvent accessibility >20%). Those HxB2 positions that were deleted in the BG505 strain as well as those that were not resolved in the crystal structure are colored in gray. A linear secondary structure diagram of the V1V2 domain is provided at the bottom of the histogram. Color images available online at www.liebertpub.com/aid