The chemotaxis pathway of R. sphaeroides. The currently known localisation and connectivity of the chemotaxis pathway in R. sphaeroides is shown. The localisation of the two signalling clusters, one at the pole and one in the cytoplasm was determined by GFP fusions and immunoflouresence . The remaining connectivities, was determined be in vitro phosphotransfer measurements and by mutant data [16, 21]. It is currently unknown what role CheY3 and CheY4 perform in the system.