ABSTRACT
Proteins are involved in every biochemical process that maintains life. Understanding protein structure will help us to unravel functions of these important molecules. Correct protein function depends on their three-dimensional structure. Thus, the key to understanding gene function is to understand protein structure. Three-dimensional motifs are more conserved than amino acid sequences. Similar motifs may serve similar functions in different proteins, e.g., Bcl-Xl and Diphtheria toxin have different sequences but similar structure and function.
