. H. pylori homologs of the A. tumefaciens conjugation machine. (A) Genetic organization of the A. tumefaciens conjugation machine. H. pylori type IV transporter components with homology to the Vir proteins are aligned underneath their homologs. (B) A model of the A. tumefaciens conjugation machine with the location of the H. pylori homologs in (A) indicated by arrows with dashed lines. This model is compiled from biochemical data described in the text predicting both the localization and interactions of the individual Vir proteins.