The Discovery of Structurally Conserved Regions by Dihedral Angles of Protein Backbone Sequence

Abstract

The structurally conserved regions are usually obtained by pairwise or multiple sequence alignment (MSA). The commonly aligned protein sequence segments are referred to as evolutionarily remained residues which constitute the structurally conserved regions. Although its direct insight into the relationship between protein sequence and structure, sequence alignment is restricted to be performed from left to right residue, i.e., from N’ to C’ terminus, or vice versa. But in reality, the tertiary structure alignments do not mention any aligned direction. In other words, the protein sequence may be aligned with another sequence which may be in a totally reversed direction. Hence, we present an algorithm to calculate the structurally conserved regions directly from the dihedral angles of protein backbone sequence instead of sequence alignment. We are convinced that the proposed algorithm behaves not only concrete and extensive but also a qualified measure index for tertiary structure alignment.