ABSTRACT
Traditionally, one of the principal aims of solving a protein’s three-dimensional structure has been to help determine how the protein achieves its biological function, that is, to gain a better understanding of how it does what it does in its specific
organism and cellular location. To date (May 2005), the structures of over 28,000 proteins have been deposited in the Protein Data Bank (PDB) (although, due to redundancy, this number corresponds to only around 8000 unique proteins). Virtually all of these structures have contributed in some way to our biological understanding of how proteins function. They have revealed how proteins recognize other molecules, how they bind their natural substrates, where in their structures the active region(s) are located, how they perform their specific biochemical reactions, and whether the proteins act alone or in concert with other molecules such as nucleotides, sugars, or other proteins.
