Fig. 4: Location of TDO2 antigen on human full-length TDO2 tetramer.
From: Autoantibody profiles associated with clinical features in psychotic disorders
The TDO2 antigen covers residue 190–278 (dark blue) of hTDO Chain A. This region covers the L-tryptophan (red) exo binding site as well as 6 of 15 Ub-sites (orange). These 6 sites include all 5 glutamic acid-proximal Ub-sites located on the helix-loop-helix protrusion of Chain A, which is rich in glutamic acid residues (yellow) with negative charge. Both the exo site and the glutamic acid-proximal Ub-sites are of importance in regulating the in vivo half-life of hTDO. Dark blue: Chain A residues corresponding to the TDO2 antigen. Orange: Ub-sites. Yellow: Glutamic acid residues. Light blue: Chain A, not covered by antigen. Ligand, red: L-Tryptophan (in exo site). Gray: Chains B–D. Source: RCSB PDB 5TI9 [20]. TDO2 Tryptophan 2,3-dioxygenase, hTDO human full-length tryptophan 2,3-dioxygenase tetramer, Ub-site ubiquitination site.
