Localization of the proteins gp7, gp8 and gp10 in the bacteriophage T4 baseplate with colloidal gold: F(ab)2 and undecagold: Fab' conjugates.

We report the localization of the proteins gp7, gp8 and gp10 in the bacteriophage T4 baseplate. Proceeding on the assumption that these proteins occupy discrete locations, we have decorated baseplates and tails with immunological probes. Using 5 nm diameter colloidal gold: F(ab')2 conjugates, we show that proteins gp7 and gp10 are located directly at the vertex, with gp10 positioned in the pin directly below gp7. gp8 is located beside gp7 towards the centre of the baseplate. Using a novel undecagold: Fab' conjugate we have also determined the radial positions of gp7 and gp8 in baseplates that have transformed to stars. A mechanism for the nature of the hexagon-to-star transformation is proposed.