Fig. 2

Structural representation of type-specific inserts of AA9 domains. Proteins are shown as cartoons and colored in gray, with the inserts colored in green and orange for region I and II, respectively. The Type 1 region I insert is colored in yellow. The AA9 structures were aligned onto cellulose Iβ using the planar aromatic residues on the AA9 active site. The cellulose is shown in black lines and the flat surface aromatic residues are represented in sticks and are colored in blue, with the type II copper ion shown as a red sphere. The planar residues Trp-34 on the model AA9 is colored in yellow as it forms part of the region I insert. On the 3ZUD crystal structure the Tyr 24 residue is colored in green as it forms part of the region I insert