Physical and functional interactions in prokaryotic taxis signaling systems. The interactions of the core signaling proteins are generally in agreement between Hbt.salinarum and the data of the other organisms. The Hbt.salinarum dataset probably contains indirect interactions (e. g. CheY-CheW, CheY-Htr) because it was generated by AP-MS. The interactions of the other Che proteins have, with the exception of CheC-CheD, not been described in other organisms. References for literature data are given in Additional file 7.