Fig. 5.

The two motifs forming the bipartite secretion signal are in direct interaction in the cryoEM structure. A. Representations of side and top views of the final atomic model of EspB built into the cryoEM map colored by domain as in Fig. 1 (PE in blue, linker in dark green, PPE in green, C-terminal domain in red). The YxxxD and WxG motifs are colored in yellow and indicated by arrows. The seven bipartite secretion signals are located on the same side of the heptamer. B. Closed view of the interaction between the YxxxD and WxG motifs in the cryoEM structure. Interaction between the two motifs is stabilized by a hydrogen bond between Y81 and W176. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)