Deep mutational scanning of a non-allosteric synthetic DHFR-LOV2 fusion construct
Sequencing data associated with "Protein Surface Site Determines the Evolutionary Accessibility of Allosteric Regulation." This study investigates the mutational landscape of a synthetic Escherichia coli dihydrofolate reductase (DHFR)-LOV2 fusion protein (DL116) using deep mutational scanning. DL116 contains the light-oxygen-voltage (LOV2) domain from Avena sativa inserted into a surface-exposed loop of DHFR, but does not exhibit detectable light-dependent allosteric regulation. A comprehensive library of single amino acid variants was subjected to competitive growth assays under illuminated and dark conditions, followed by Illumina sequencing to quantify variant frequencies over time. These sequencing data were used to measure the effects of individual mutations on protein fitness and to evaluate whether single substitutions can give rise to light-dependent allosteric regulation. The dataset provides a resource for studying the sequence determinants of protein function and the evolutionary accessibility of engineered allosteric regulation following domain insertion.