Figure 7.

Two potassium ions which cluster the three AH molecules. One of the two potassium ions is surrounded by three Asn carbonyl O atoms and three O² atoms of Man¹ to form an octahedron. Another potassium ion is bound to three O⁴ atoms of Man¹, on the opposite side to which several water molecules are disordered. These ligands are related by the crystallographic threefold symmetry. Full black lines show coordination bonds around the two potassium cations (with their distances in Å) and dashed green lines indicate possible hydrogen bonds between the three Man¹s: O³⋯HO² and O³H⋯O⁶ in each.