HH-suite is an open-source software package for sensitive protein sequence
 searching based on the pairwise alignment of hidden Markov models (HMMs).
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 This package contains HHsearch and HHblits among other programs and utilities.
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 HHsearch takes as input a multiple sequence alignment (MSA) or profile HMM
 and searches a database of HMMs (e.g. PDB, Pfam, or InterPro) for homologous
 proteins. HHsearch is often used for protein structure prediction to detect
 homologous templates and to build highly accurate query-template pairwise
 alignments for homology modeling.
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 HHblits can build high-quality MSAs starting from single sequences or from
 MSAs. It transforms these into a query HMM and, using an iterative search
 strategy, adds significantly similar sequences from the previous search to
 the updated query HMM for the next search iteration. Compared to PSI-BLAST,
 HHblits is faster, up to twice as sensitive and produces more accurate
 alignments.