Quorum Sensing (QS) mediated by Acyl Homoserine Lactone (AHL) molecules are probably the most widespread and studied among Gram-negative bacteria. Canonical AHL systems are composed by a synthase (LuxI family) and a regulator element (LuxR family), whose genes are usually adjacent in the genome. However, incomplete AHL-QS machinery lacking the synthase LuxI is frequently observed in Proteobacte...

Two distinct but interrelated pheromone-signaling systems, LuxI/LuxR and AinS/AinR, positively control bioluminescence in Vibrio fischeri. Although each system generates an acyl-homoserine lactone (AHL) signal, the protein sequences of LuxI/LuxR and AinS/AinR are unrelated. AinS and LuxI generate the pheromones N-octanoyl-AHL (C8-AHL) and N-3-oxo-hexanoyl-AHL (3OC6-AHL), respectively. LuxR is a...

Numerous gram-negative bacteria communicate and regulate gene expression through a cell density-responsive mechanism termed quorum sensing (QS), which involves the synthesis and perception of diffusible N-acyl-homoserine lactones (AHL). In this study we genetically and physiologically characterized the Burkholderia thailandensis DW503 QS network. In silico analysis of the B. thailandensis genom...

Many species of Proteobacteria communicate by using LuxI-LuxR-type quorum-sensing systems that produce and detect acyl-homoserine lactone (acyl-HSL) signals. Most of the known signals are straight-chain fatty acyl-HSLs, and evidence indicates that LuxI homologs prefer fatty acid-acyl carrier protein (ACP) over fatty acyl-CoA as the acyl substrate for signal synthesis. Two related LuxI homologs,...

objectives: in present study we aimed to clone the lux i gene encoding n-acyl-homoserine synthase detected in biofilm forming clinical isolates of acinetobacter baumannii and study its expression in escherichia coli transformants. materials and methods: four a. baumannii hospital strains which demonstrated strong biofilm activity were selected in this investigation. the presence of lux i gene w...

Background: LuxI is a component of the quorum sensing signaling pathway in Vibrio fischeri responsible for the inducer synthesis that is essential for bioluminescence. Methods: Homology modeling of LuxI was carried out using Phyre2 and refined with the GalaxyWEB server. Five models were generated and evaluated by ERRAT, ANOLEA, QMEAN6, and Procheck. Results: Five refined models were gener...

We report for the first time the draft genome sequence of two psychrotrophic Pseudomonas species, Pseudomonas simiae RGCB 73 and Pseudomonas brenneri RGCB 108, from the Arctic that produce more than one acyl homoserine lactone molecule of varied N-acyl length. The study confirms the presence of a LuxR-LuxI (type) mediated quorum-sensing system in both the Pseudomonas species and enables us to u...