Abstract
AbstractProkaryotic transcription factors (TFs) regulate gene expression in response to small molecules, thus representing promising candidates as versatile small molecule-detecting biosensors valuable for synthetic biology applications. The engineering of such biosensors requires thoroughin vitroandin vivocharacterization of TF ligand response as well as detailed molecular structure information. In this work we characterize the PcaR TF belonging to the IclR family. We presentin vitrofunctional analysis of PcaR’s ligand profile and construction of genetic circuits for the characterization of PcaR as anin vivobiosensor in the model eukaryoteSaccharomyces cerevisiae. We report the crystal structures of PcaR in theapostate and in complex with one of its ligands, succinate, which suggests the mechanism of dicarboxylic acid recognition by this TF. This work provides key structural and functional insights enabling the engineering of PcaR for dicarboxylic acid biosensors.Graphical AbstractHighlightsPcaR is an IclR family transcription regulator responsive to dicarboxylic acidsPcaR was established as anin vivobiosensor in yeastCrystal structure of PcaR in theapoform was solvedCrystal structure with PcaR in complex with succinate was solvedSequence alignments unveil ligand-binding positions in the IclR family
Publisher
Cold Spring Harbor Laboratory