Zhifeng Jing, Rui Qi, Chengwen Liu and Pengyu Ren
Structures of model compounds for ion-binding pockets. (A) and (B) are Mg-binding pockets while (C) and (D) are Ca-binding pockets. White, cyan, blue, red, pink and green spheres are H, C, N, O, Mg and Ca atoms. All these four structures consist of four acetate molecules and one acetamide, and (B-D) have an additional water molecule. (A) and (C) each has one bidentate acetate, and all the other acetate bind to the metal ion with one oxygen atom. These four models are denoted as Mg-Bi, Mg-Mono, Ca-Bi and Ca-Mono respectively.