Fig. 4.

Arginase I–ABH complexes. Summary of average intermolecular interactions in the human arginase I–ABH complex (gray numbers) and the rat arginase I–ABH complex (orange numbers). Note that the higher resolution of the human arginase I–ABH structure allows for more accurate hydrogen bond distance measurements. Manganese coordination interactions are indicated by green dashed lines, and hydrogen bonds are indicated by black dashed lines. Several slightly shorter and stronger enzyme-inhibitor hydrogen bond interactions are observed in the human enzyme, consistent with its enhanced affinity for ABH (Table 2).