Crystallization of Pseudomonas aeruginosa AHL synthase LasI using beta-turn crystal engineering.

In Gram-negative bacteria, intercellular communication and virulence regulation is mediated by the diffusible chemical signal acyl-homoserine-L-lactone (AHL). The AHL synthase enzymes produce a variety of AHLs from the substrates S-adenosyl-L-methionine and acyl-acyl carrier protein. LasI, the AHL synthase from Pseudomonas aeruginosa, has low solubility and has failed to crystallize despite extensive crystallization trials.

Structural basis and specificity of acyl-homoserine lactone signal production in bacterial quorum sensing.

Synthesis and detection of acyl-homoserine lactones (AHLs) enables many gram-negative bacteria to engage in quorum sensing, an intercellular signaling mechanism that activates differentiation to virulent and biofilm lifestyles. The AHL synthases catalyze acylation of S-adenosyl-L-methionine by acyl-acyl carrier protein and lactonization of the methionine moiety to give AHLs. The crystal structure of the AHL synthase, EsaI, determined at 1.