Figure 1

Schematic of QS regulation of V.fischeri bioluminescence and competitive model. (A) QS regulation of bioluminescence in V.fischeri uses three autoinducer channels [8]. The autoinducer 3OC6HSL is synthesized by LuxI and binds to LuxR to form a transcriptional activator for the bioluminescence genes luxCDABEG. Two more autoinducers (C8HSL and AI2) drive the phosphorelay that regulates production of LuxR as well as other colonization behaviors. (B) A simplified model considers only competitive interaction between 3OC6HSL and C8HSL, as proposed by Kuo et al. [13] and Lupp et al. [11]. The receptor LuxR binds the autoinducers C8HSL and 3OC6HSL to form multimeric complexes (of degree m and n respectively) which activate lux transcription. In our fit we omit lux activation by the C8HSL complex of LuxR.