(A) Distribution of conserved DUF2169 domain from Atu3641 across different bacterial phyla according to Pfam database. (B) Selected bacterial species in which the DUF2169-containing protein is linked with VgrG2 orthologs and effectors other than Tde2/Tde2L. Gene ID of VgrG2 orthologs from top to bottom: 739337228, 654370902, 590115676, 741017205, 498355758, 657887367. (C) Stability of Tde2HD-Strep in the presence and absence of Atu3641-HA. Tde2HD-Strep was expressed alone or with Atu3641-HA in the A. tumefaciens ∆tde2–atu3641 deletion strain. Western blot analysis of total protein from cells grown in 523-medium. Band intensity of Tde2HD-Strep was quantified by using ImageJ software (49) and expressed as a percentage of the plasmid-only control, which was set to 0%. Data are mean ± SEM obtained from four independent experiments, ***P < 0.01. Representative blot at the bottom shows a Tde HD -Strep and Atu3641-HA protein band. 1: ∆tde2-atu3641 (p); 2: ∆tde2-atu3641 (p-Tde2HD-Strep); 3: ∆tde2-atu3641 (p-Tde2HD-Strep + Atu3641-HA).