Figure 3. Phenotype summary of VirB2 variants.

VirB2 amino acid substitutions are indicated with the levels of extracellular VirB2 (ExB2) production and occurrence or size of tumor formation on tomato stems (Vir) with wild type (+++), modest reduction (++), highly attenuation (+), or loss (−). VirB2 protein sequences with indicated conserved amino acid residues, regions/domains, and the processing site (indicated by an arrow) are presented as described in Figure 1. The 34 VirB2 variants are classified into three groups: ExB2⁻/Vir⁻, ExB2⁻/Vir⁺, and ExB2⁺/Vir⁺ shown in red, green and black, respectively.