Quorum Sensing in Gram Positive Bacteria

1. Oligopeptides are cleaved into small functional units and secreted out of the bacterium through a transporter protein.
2. Signal oligopeptides are detected by a sensor protein on the bacterium's surface when they reach a significant concentration.
3. The protein becomes phosphorylated and the phosphate is transferred to a response regulator protein.
4. The phosphorylated regulator protein binds to a specific DNA site and alters transcription in the target gene.

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 positive quorum sensing may be found approximately halfway 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