Figure 3.

Small amounts of protein B2 interact with protein A and segregate with purified mitochondria. (A) Subsets of nodavirus proteins A and B2 physically interact. Antibodies directed against protein A co-immunoprecipitate protein B2 and antibodies directed against protein B2 co-immunoprecipitate protein A. The interaction is insensitive to micrococcal nuclease treatment, showing that it is not mediated through RNA. (B) Cell fractionation procedures to isolate mitochondria show that the majority of protein A but only a small amount of protein B2 (~8%) tracks with mitochondrial marker VDAC, while the great bulk of protein B2 tracks with cytoplasmic tubulin.