FIG. 7.

Working model for the role of CheB and CheR proteins in A. brasilense chemotaxis. The CheB (B) and CheR (R) proteins under study and the che pathway are shown in solid black lines. Other putative chemotaxis homologs are shown in gray. W, A, and Y represent CheW, CheA, and CheY, respectively. Cytoplasmic C-terminal domains of putative chemotaxis transducers interacting with CheB and CheR are shown as a rectangle and a diamond. The model argues that the primary function of the chemotaxis pathway under study is probably not to control motility behavior. CheB and CheR may contribute to chemotaxis and aerotaxis because of their effect on the methylation status of the chemotaxis transducer(s) that is ultimately involved in controlling motility (see text for details).