SEG filtering of low-complexity segments
SEG Output. The human MGT8a sequence has been divided by SEG into low complexity sequence (left) and high complexity sequence (right). The low complexity sequences detected in this example are largely obvious homopolymeric runs and other stretches of biased amino acid composition. More subtle over-representation of one or a few amino acids are also recognized by SEG. More than half of the proteins in the database contain at least one low complexity region. The default filtering option in BLAST 2.0 automatically converts low complexity sequences into X's which can be seen in the query line of the alignments. Database entries are not filtered by BLAST 2.0.