Alimask adds a mask line to a multiple sequence alignment. Alimask is used to apply a mask line to a multiple sequence alignment, based on provided alignment or model coordinates. When hmmbuild receives a masked alignment as input, it produces a profile model in which the emission probabilities at masked positions are set to match the background frequency, rather than being set based on observed frequencies in the alignment. Position-specific insertion and deletion rates are not altered, even in masked regions. alimask autodetects input format, and produces masked alignments in Stockholm format.
Parent program: hmmer
HMMER software allows search for protein homologs and also permits multiple protein sequence alignment. Unlike BLAST, HMMER uses probabilistic models called profile hidden Markov models which provide a significantly more accurate and more sensitive detection of remote homologs. The HMMER software suite has been widely used, particularly for protein family databases such as Pfam and InterPro and their associated search tools. Also HMMER has several programs for protein sequence analysis such as phmmer, hmmscan, hmmsearch and jackhmmer.