FIG 2.

Transfer of A. tumefaciens effectors through the E. coli pKM101 conjugation channel. (A) E. coli donors produced the TraJ/VirD4_At chimera. As controls, donors produced either the VirD4_At soluble domain (SD_VirD4At) (upper bars) or the TraJ/VirD4K152Q_At variant bearing a nucleotide-binding site mutation (lower bars). Transfer of Cre alone; Cre fused to the VirE2, VirE3, or VirF effector; or Cre fused to VirE2's C-terminal 100 residues (CT100) or VirE2 with its last 50 residues deleted (VirE2ΔC50) was monitored by CRAfT (50). The values represent the means of at least three experiments with standard deviations. *, P < 0.01 versus Cre-only transfer; statistical analyses using Student's t test. (B) Steady-state levels of Cre or Cre-effector fusion proteins in E. coli donors, detected by immunostaining with anti-Cre antibodies. Lane Vector, donors carrying the vector plasmid only. Cre fusion proteins are marked by squares; Cre and prominent Cre breakdown products are marked by rectangles. Cre antibodies also cross-reacted with unknown proteins.