Fig. 2.

Interactions with ligands for YuiC and MltA. a Interaction of YuiC (cyan) with NAG (green) (H bonds shown as black dotted lines and non-carbon atoms O red and N blue). b Interaction of YuiC (yellow) with 1,6-anhydrodisaccharide (green). 2Fo-Fc electron density for the ligand at 1.0 sigma shown clipped to 1.5 Å around the ligand. c Interaction of MltA (magenta) with hexachitose (dark cyan) (PDB 2pi8) [20]. 2pi8 is a D308A mutation to prevent catalysis so D308 (light crimson) from the superposed active MltA (PDB 2ae0) is shown [19]. a-c are superimposed views d superposition of YuiC (yellow) with MltA (magenta) showing the superposition of substrates hexachitose (dark cyan) and the 1,6-anhydrodisaccharide (green). This shows the ligands overlapping at the −1 and −2 sites. The sidechains of the three conserved aspartates giving rise to the 3D domain name are also shown. e The potential clash of the ends of a hexachitose in the YuiC structure showing the +2 NAG of MltA (2pi8) clashing with chain B domain swapping helix (dark crimson helix and transparent grey surface) and the −4 NAG clashing with a symmetry related copy of YuiC in the lattice (dark green and transparent grey surface). Diagrams drawn with CCP4mg [37]