Software-information system Protein Structure Discovery was developed. The system can be used for the wide range of tasks in the field of computer proteomics including prediction of function, structure and immunological properties of proteins. A specially created section of the system allows evaluating the quantitative and qualitative effects of mutations on the structural and functional properties of proteins. There are 19 of different programs integrated into the system, including the database of protein functional sites PDBSite, a PDBSiteScan program for the prediction of functional sites in three-dimensional structures of proteins, and WebProAnalyst program for the quantitative analysis of the structure-activity relationship of proteins. Protein Structure Discovery program has a Web interface and is available for users through the Internet (http://www-bionet.sscc.ru/psd/). For example, binding sites of zinc ion and ADP showed high stability of the method to errors PDBSiteScan reconstruction of spatial structures of proteins in the recognition of functional sites in model structures.