Fig. 1: Constructing and optimizing itaconate biosensor.

a Overall structure of IBD in apo (left, PDB: 7W08) or itaconate-bound (right, PDB: 7W07) state. The dotted lines circumscribed the zone of itaconate binding pocket and the key amino acid residues that interact with itaconate were shown. b Overlay and structural alignment of IBD in apo (gray) and itaconate bound (green and blue) states. The largest structural rearrangement of each monomer is shown upon ligand binding. The N- and C-termini of the IBD are highlighted with the terminal residues in red and their associated displacement following ligand binding is labeled in angstroms. c Maxima values from emission peaks (monitored at 530 nm after excitation at 488 nm) of indicated itaconate biosensors were measured in the presence of 10 mM itaconate. These values were shown by heatmap after normalization to F0 (maxima values from emission peaks of the corresponding sensors in the absence of itaconate). Data are shown as mean ± SD (n = 3). d Schematic drawing of the itaconate biosensor BioITA. Fluorescent protein cpGFP was inserted between IBD and CENP-B. Itaconate binding changes conformation in protein to induce fluorescence. IBD itaconate-binding domain, cpGFP circularly permuted green fluorescent protein, CENP-B human centromere protein B. Source data are provided as a Source Data file.