N-decanoyl-L-homoserine lactone (C10-HSL) is a quorum sensing signaling molecule produced by certain Gram-negative bacteria, such as Pseudomonas species, that enables the coordination of group behaviors like biofilm formation, virulence factor production, and motility. The biosynthesis of C10-HSL is catalyzed by acyl-homoserine lactone (AHL) synthase enzymes, typically homologs of LuxI. The biosynthetic pathway begins with L-homoserine, which serves as the core backbone of the molecule. The C10 fatty acyl group, derived from decanoyl-CoA, is transferred by the AHL synthase enzyme, forming an amide bond with the amino group of L-homoserine. This intermediate is then cyclized to form the lactone ring, resulting in the production of N-decanoyl-L-homoserine lactone (C10-HSL). Additionally, certain LuxI homologs can modify the acyl group to include a keto group at the third carbon, resulting in the production of N-(3-oxodecanoyl)-L-homoserine lactone (3-oxo-C10-HSL). Both C10-HSL and 3-oxo-C10-HSL act as quorum sensing molecules, diffusing into the extracellular space where their concentration builds as the bacterial population grows. When the concentration of these molecules reaches a critical threshold, they bind to LuxR-type receptors, forming complexes that activate the transcription of genes involved in quorum sensing-regulated behaviors. This system allows bacteria to synchronize their actions in response to population density, enhancing their ability to form biofilms, regulate virulence, and adapt to changing environmental conditions.

Quorum sensing: N-decanoyl-L-homoserine lactone (C10-HSL) and N-(3-Oxodecanoyl)-L-homoserine lactone Biosynthesis References