Fig. 7

Predicted acyl binding cavity structures of modelled wild-type and mutant ALTs. Computational models of the predicted ALT active unit indicate that introduction of the 31-CQH[G/C]RH-36 motif leads to disruptions in the acyl-binding cavity structure of AtALT4 and MtALT1, while altering the 108-KXXA-111 motif compromises substrate-binding cavity depth in AtALT3 and MtALT2. Ribbon structure of α1-α2 of the hot-dog fold thioesterase domain (aa24–54) is hidden for increased visibility of individual residues. Predicted cavity-forming residues are shown as stick models, and molecular surfaces formed by these residues are coloured according to hydrophobicity (yellow = hydrophobic, white = amphipathic, blue = hydrophilic). Models of wild-type ALT monomers were created by AlphaFold 2.0, and tetramer assemblies were constructed with HSYMDOCK [39,40,41]. The effects of amino acid mutations were simulated using the FoldX 5.0 suite [54]. Models were visualized in ChimeraX 1.2.5 software [42]