A.R. Kayumov, M.I. Bogachev

Pathogenic bacteria have different polypeptide instruments, that (i) allow to penetrate the host organism, and (ii) support the protection of the microorganism from the host immune system. These functions are normally per-formed by proteins (that may be also coupled to carbohydrates) that are called pathogenicity factors. Each protein is responsible for particular functions of the microorganism in the infectionous process. They include factors of adhesion and colonisation; factors of invasion; factors preventing fagocytose, ferments of bacterial «protection and agression». The localization of key amino acids involved in the substrate binding and recognition and participating in cathalytic reaction in the protein primary structure of the biopolymer, can be treated as the biological system signal. In this paper, the primary protein structure is analyzed by a highly specific approach based on interval statistics. The efficiency of this approach for biological sequence analysis has been recently demonstrated by the authors. The original data for the analysis has been obtained from the pathogenicity factors database. Analyzed proteins has been originally classified according to their functional role in the cell. The analysis of amino acid sequences revealed significant statistical differences in the primary structure of proteins related to the cell wall. In these proteins several amino acids characterized by a broad distribution of intervals have been detected. Currently the functional and the evolutionary role of the broad distribution in some amino acids remains unknown. It is possible that these components are more essential for the secondary and triple protein globule formation than for the functional activity of the particular protein.