Figure 3. Schematic of the part of TSR that interacts with Pofut2.
A) Truncated TSR4 from F-spondin used in experiments to demonstrate essential structural elements required for substrate recognition by Pofut2 [59].
B) Distribution of various residues of a TSR involved in enzyme-substrate reaction. Of about 30 sites involved in enzyme interaction, 10 are conserved (amongst known Pofut2 substrates), 9 are solvent exposed, and the rest have highly variable side-chains. While specific residues in the active site interact with the conserved regions of the TSR, large cavities in the substrate-binding pocket can accommodate the variable side chains [59].