Fig. 2.

Domain organization of the three different C. jejuni Tlp-chemoreceptor groups: group A receptors are anchored by membrane-spanning regions in the inner and obviously also in the outer membrane, have a periplasmic sensory and a cytoplasmic signalling domain; the only group B receptor Tlp9 (CetA), anchored in the inner membrane, interacts with CetB triggering pyruvate and fumarate signals [84]; group C chemoreceptors consist of a single cytoplasmic signalling domain; the cytoplasmic Tlp7c (encoded by cj0951c) receptor is assigned to group C, while it was shown that there is no read-through mechanism [77], whereas the membrane associated forms Tlp7m (encoded by cj0952c) and Tlp7mc (encoded by cjj81176-0975 according to the nomenclature of the 81-176 sequence) are assigned to group A (depiction modified after Marchant et al. [30])