Multiple sequence alignment is an invaluable technique for identifying similarities and differences among a series of related sequences. While sequences alignments provide a map of how sequences may have evolved from a common ancestor, they are not particularly robust for identifying sequence similarities that are rapidly changing in insertion, deletion, and repeat content. In order to identify hidden commonalities and differences among rapidly evolving sequences, we have employed a method to characterize them based on their amino acid composition, not on stringent amino acid alignment positions. Thereby, we are able to demonstrate how portions of some sequences, that evolving quickly, are preserving a specific enrichment of amino acids while changing the overall placement of these residues.

The web-based Sequence Enrichment Visualization Tool enables users to upload PIR-formatted raw and aligned sequences to visualize specific enrichments and depletions in particular amino acids. Individuals have the opportunity to define the coloring of particular amino acids. Using this tool, researchers are able to simultaneously highlight enriched amino acid contents within a set of sequences.