Protein topology and allostery.

Allostery plays important roles in many biological processes. Although all non-fibrous proteins may be allosteric, currently only a limited number of allosteric proteins are known. How allosteric regulation depends on protein topology and what are the preferred folds in allosteric proteins need to be explored. Allosteric sites are found more often between chains or domains in multimeric or multi-domain proteins, while they often occur on the opposite side of the structure of the protein from the orthosteric site in monomeric single domain proteins. Although most folds are found in allosteric proteins, the immunoglobulin-like fold is rarely used. Typical regulatory domains include alpha-beta plaits, PDZ, WW domains, and so on. According to the understandings of allosteric regulations, novel allosteric proteins and materials have been rationally designed.