Fig. 5.
Functionality of VirB8sp variants in B. suis and in the heterologous T4SS assembly assay in A. tumefaciens. (A) J774 macrophages were infected with B. suis 1330 (wt), BS1008 (ΔvirB8), and BS1008 carrying plasmids for expression of VirB8s and its variants, and intracellular growth was quantified 48 h after infection (logarithmic scale, geometric mean ± standard deviation from 3–12 independent repetitions). Complementation by pIN38 (VirB8s wt) is indicated by the dashed line. (B) The recipient UIA143 carrying pTrcB1+3–12 (wt), pTrcB1+3–12ΔvirB8 (ΔvirB8), and strains complemented with pTrcPVirB8s and variants were cocultivated with the donor A348 pLS1. The transconjugants (TC) were identified by growth on selective agar, and the pLS1 transfer efficiency (transconjugants per recipient, TC/R) into UIA143 carrying pTrcB1+3–12ΔvirB8, and pTrcPVirB8s was set to 100% (indicated by dashed line) (error bars show standard deviation from four repetitions, and bacterial titer is given in a linear scale).