FIGURE 5.

Interactions of AMP-PCP with spSRw in the open form. The simulated annealing omit map is contoured at the 1.0 σ level. AMP-PCP interacts with the small and large domain residues (gray sticks with red oxygen and blue nitrogen) of one subunit and the large domain residues (orange sticks) of the other subunit. Hydrogen bonds are shown by dotted lines (green). Met-53, Asn-84, Gln-87, Glu-281, and Asn-311 (blue sticks) form a hydrogen bond network (red) to link PLP and AMP-PCP. The magnesium ion is surrounded by β- and γ-phosphate and four water molecules. The water molecules are involved in direct hydrogen bonds with the neighboring amino acid residues.