Figure 2
(a) Cα superposition of BoGT6a and BoGT6a-FAL structures.Structural variations in loop regions Loop1 (126–151) in red, Loop2 (175–190) in forest green, Loop3 (66–67) in sand, C-term (228–234/236) in purple of BoGT6a-FAL are shown. BoGT6a loops and C-term are coloured in marine blue; (b) Surface potential charge representation of BoGT6a with the bound FAL and modelled UDP-GalNAc molecule; (c) Chemical structure of FAL. Only the 1st carbon atom positions are labelled for each of the monomeric unit; (d) Observed electron density [(2Fo-Fc) map contoured at 1.0σ] for the bound FAL in the structure of the complex; (e) Acceptor binding site of BoGT6a with interacting residues and ligand FAL (2FAL) shown as ball-and-stick model. The position of Trp189 both in native BoGT6a (in yellow) and BoGT6a-FAL complex (in green) is shown and labeled in red (BoGT6a) and in black (BoGT6a-2′-fucosyllactose). The reorientation of this loop (Loop2) stabilizes Loop1 that shares hydrogen bonding interactions with the bound FAL. Residues interacting with 2′-fucosyllactose from molecule B are coloured in grey.
