The S-Helix Determines the Signal in a Tsr Receptor/Adenylyl Cyclase Reporter

摘要: A signaling or S-helix has been identified as a conserved, up to 50-residue-long segment in diverse sensory proteins (1). It is present all major bacterial lineages and euryarchea eukaryotes bioinformatic analysis shows that it connects upstream receiver downstream output domains, e.g. histidine kinases adenylyl cyclases. The modeled two-helical parallel coiled coil. predicted prevent constitutive activation of the domains absence ligand-binding We an about 25 residues cyclase CyaG from Arthrospira maxima. Deletion residue connecting HAMP catalytic chimera with Escherichia coli Tsr receptor changed response serine inhibition stimulation. Further examination showed deletion one three heptads plus presumed stutter, i.e. 1, 2, 3 × 7 + 4 amino acids, required sufficient for signal reversion. was not necessary deletions be continuous, removal separated stutters also resulted Furthermore, insertion above segments between similarly This indicates independent, segmented module capable reverse signal. Because kingdoms life, human retinal guanylyl cyclase, our findings may significant many systems.