STRUCTURE, FUNCTIONS, AND EVOLUTION OF THE 3RD-COMPLEMENT COMPONENT AND VIRAL MOLECULAR MIMICRY

The third component of the complement system, C3, is a common denomina tor in the activation of the classical, alternative, and lectin pathwa ys. The ability of C3 molecule to interact with at least 20 different proteins makes it the most versatile component of this system. Since t hese interactions are important for phagocytic, immunoregulatory, and immune evasion mechanisms, the analysis of its structure and functions has been a subject of intense research. Here we review our current wo rk on the C3-ligand interactions, C3-related viral molecular mimicry, evolution of the complement system, and identification of C3-based com plement inhibitors.