FIG. 1.

Interactions of VirB7, VirB8, VirB9, and VirB10. Interaction of VirB proteins was studied by the yeast two-hybrid assay (16). Yeast strains harboring the appropriate plasmids were streaked on solid medium containing X-Gal. A positive interaction is manifested by the blue colony color phenotype. The interactions of VirB7 (B7), VirB8 (B8), VirB9 (B9), and VirB10 (B10) with one another were investigated. One interacting protein is indicated on the left column and the partner proteins are indicated under the colony. For control (C) experiments, the activator vector was introduced into a strain containing the LexA-VirB8, -VirB9, or -VirB10 fusion.