AH-DB (Apo and Holo structures DataBase) collects apo and holo structure pairs of proteins. Various protein functions have ben shown directly associated with conformational transitions triggered by binding other molecules. Tertiary structures determined in the unbound and bound state are usually named apo and holo structures, respectively. In AH-DB, we extended the definition of apo and holo structures. The apo strcuture of a protein could be in a apo complex containing other molecules. The corresponding holo strcuture must be in a holo complex containing all the molecules in the corresponding apo complex and some added molecules.

AH-DB is the largest database of apo-holo strcture pairs and provide a sophisticated interface to search and view the collected data. It contains 746314 apo-holo pairs of 3638 proteins from 702 organisms. See more detailed statistics.