The Putative Endoglucanase PcGH61D from Phanerochaete chrysosporium Is a Metal-Dependent Oxidative Enzyme that Cleaves Cellulose
Figure 2
Sequence and structural analysis.
Panel A shows a structure-based sequence alignment of PcGH61D and GH61A from Thermoascus aurantiacus with GH61s with known crystal structures, TtGH61E and HjCel61B. Residues in the metal ion-binding site of the proteins are indicated by triangles in the sequence alignment. The position of a large insertion in the HjCel61B structure and corresponding region in TaGH61A is marked with a red box. Panel B shows surface representations of TtGH61E (left), PcGH61D (middle), and HjCel61B (right). The metal ion binding sites are coloured blue. The red surface in HjCel61B corresponds to the red box in panel A. Panel C shows a superposition of the metal binding sites of TtGH61E (PDB code: 3EII, coloured green), HjCel61B (PDB code: 2VTC, coloured light-blue), and the PcGH61D homology model (coloured orange). The light blue and green spheres indicate the nickel ion found bound in the HjCel61B structure and the zinc ion bound in the TtGH61E structure, respectively. Red spheres indicate water molecules in the two structures HjCel61B and TtGH61E. Grey dashed lines indicate interactions with the bound metals.