FIGURE 2.

X-ray crystal structure of GH20C. A, GH20C monomer with the loops represented in gray and the domains represented in green schematic for the N-terminal domain, yellow for the central (β/α)₈ domain, and purple for the C-terminal domain. B, GH20C dimer with one monomer colored as in A and the other monomer represented as a slate blue surface. C, overlay of the GH20C active site (yellow stick representation for side chains and transparent gray schematic representation of the backbone) with GcnA (cyan stick representation for side chains) in complex with NGT (salmon stick representation). The numbering refers to that of the GH20C polypeptide.