FIG 9.

FI6v3 bound to X31 may disrupt the dense network of HA on the surface of the virus. Shown is a 6.4-nm-thick computational slice of FI6v3 bound to X31 at a ratio of 1:2 (IgG/HA). Black arrowheads point toward FI6v3 IgG-bound HA. Additional density ∼6 nm above the viral membrane corresponds to FI6v3 bound to the stem region of HA2. FI6v3 fails to aggregate X31 due to the epitope's location further down the HA stem. The IgG-virus mixture was incubated for 30 min prior to vitrification. Bar = 25 nm.