Role of the LuxR solo, SdiA, in eavesdropping on foreign bacteria
Andrew Schwieters, Brian M. M. Ahmer
Abstract
Bacteria can cooperate by coordinating their gene expression through the production, release, and detection of small molecules, a phenomenon known as quorum sensing (QS). One type of QS commonly found in Gram-negative bacteria utilizes a LuxI-type enzyme to produce a signaling molecule of the N-acyl-homoserine lactone (AHL) family, and a transcription factor of the LuxR family to detect and respond to the AHL. In a subset of Enterobacteriaceae, including Escherichia coli and Salmonella, no LuxI family member is present and no AHLs are synthesized. However, they encode a LuxR family member, SdiA, that is used to detect the QS molecules of other bacterial species, a behavior known as eavesdropping. Despite significant research on the topic, the overall role of SdiA-mediated eavesdropping in these bacteria remains unclear. In this review, we discuss the phenotypes and regulons of SdiA in the Enterobacteriaceae.