Quorum Sensing in Gram Negative Bacteria

1. Acyl homoserine lactoses are synthesized by enzymes and move through the bacterium membrane via passive diffusion.
2. When a significant concentration of lactoses is reached, it binds and activates a regulatory protein on the cell membrane.
3. The regulatory protein then binds to a specific DNA site and influences the target gene. It also induces more production of the lactose signaling molecules.

An interactive video may be found here: http://highered.mcgraw-hill.com/olcweb/cgi/pluginpop.cgi?it=swf::500::500::/sites/dl/free/0073375225/594358/QuorumSensing.swf::Quorum%20Sensing

(Gram negative quorum sensing may be found approximately a third of the way through the video)

Sources:

Image: http://www.sciencedirect.com/science/article/pii/S1369527499000259

http://highered.mcgraw-hill.com/olcweb/cgi/pluginpop.cgi?it=swf::500::500::/sites/dl/free/0073375225/594358/QuorumSensing.swf::Quorum%20Sensing