Structural patterns in alpha helices and beta sheets in globular proteins.

Secondary structural elements like alpha-helix and beta-sheet constitute the major components of proteins. Here we present a systematic position wise analysis of the structural and sequence characteristics of alpha-helices and beta-sheets. Helix and sheet are found to follow a complementary distribution pattern along the protein chain length. We have calculated the conformational parameters of the amino acids forming helices and sheets. Other properties like hydrophobicity, temperature-factor and relative entropy are found to be correlated with the distribution pattern of these secondary structures. This gives an insight about the conservation or variation of the secondary structure in proteins, which may have significant implications on de novo protein design.