FIG 5.

Sodium atom interactions between the CR10 P domain and sCD300lf. The sodium atom (orange sphere) is held with the CR10 P domain residues (Asn364^CR10 and Asp366^CR10), CDR3 residues of sCD300lf (Lys94^CD300lf, Gly96^CD300lf, and Asp98^CD300lf), and a water molecule (marine sphere). Interactions are shown as yellow lines. This set of interactions formed an octahedron-like structure, which was also observed in the apo sCD300lf structure (25). The Omit map (mFo-DFc, blue mesh) is countered at 3.0 σ.