HMMER(1) HMMER Manual HMMER(1)
HMMER - profile HMMs for biological sequence analysis
Align sequences to a profile
Construct profile(s) from multiple sequence alignment(s)
Convert profile file to various HMMER and non-HMMER formats
Sample sequences from a profile
Retrieve profile HMM(s) from a file
Prepare an HMM database for hmmscan
Search sequence(s) against a profile database
Search profile(s) against a sequence database
Collect profile score distributions on random sequences
Summary statistics for a profile file
Iterative search of a protein sequence against a protein sequence database
Search a protein sequence against a protein sequence database
HMMER is a suite of several programs for biological sequence alignment and database homology search. It uses probabilistic models called
"profile hidden Markov models" (profile HMMs) to represent the likely evolutionary homologs of a single sequence or a multiple alignment of
a sequence family. A main avenue of research is to improve the evolutionary predictive models in HMMER to be able to recognize and accu-
rately align increasingly remote homologs, distant in time.
HMMER is also used as an organizational tool, to group the exponentially growing number of biological sequences into a vastly smaller set
of well-annotated sequence families. New sequences can be annotated by comparison against curated sequence family databases of prebuilt
HMMER profiles, in addition or instead of comparison to the entire sequence database. Databases such as Pfam, SMART, and TIGRfams, among
others, are based on this principle.
HMMER is used in three main modes: to search a sequence database for new homologs of a sequence or a sequence family; to search a profile
database (like Pfam) to find what known family a query sequence belongs to, or what domains it has; and to automatically construct large
multiple alignments (i.e. with an effectively unlimited number of sequences) using a profile representative of a sequence family.
Suppose you have a multiple sequence alignment of a sequence family of interest, and you want to search a sequence database for additional
homologs. The hmmbuild program builds profile(s) from multiple alignment(s). The hmmsearch program searches profile(s) against a sequence
Suppose you have a single sequence of interest, and you want to search a sequence database for additional homologs. The phmmer program
searches a single protein sequence against a protein sequence database. The jackhmmer program does the same thing but iteratively --
homologs detected in a previous round are incorporated into a new profile, and the new profile is searched again. phmmer is used like
BLASTP, and jackhmmer is used like a protein PSI-BLAST. Currently these two programs support only protein/protein comparison, but this will
change with time.
Suppose you have sequence(s) that you want to analyze using a HMMER-based profile HMM database like Pfam (http://pfam.sanger.ac.uk). The
hmmpress program formats a profile HMM flatfile (such as the file you would download from Pfam) into a HMMER binary database. The hmmscan
program searches sequence(s) against that database.
Suppose you want to align lots of sequences. You can construct a manageably small alignment of a representative set of sequences, build a
profile with hmmbuild, and use the hmmalign program to align any number of sequences to that profile.
HMMER also includes some auxiliary tools for working with large profile databases. hmmfetch fetches one or more profiles from a database.
hmmstat prints summary statistics about a profile file.
For compatibility with other profile software and previous versions of HMMER, the hmmconvert program converts profiles to a few other for-
mats. We intend to add more support for other formats over time.
The hmmemit program generates (simulates) "homologous" sequences by sampling from a profile. It can also generate a "consensus" sequence.
The hmmsim program is a simulator used for collecting statistics about score distributions on random sequences.
Each program has its own man page.
This is a summary man page for the entire HMMER3 package. See individual man pages [hmmbuild(1), for example] for usage, options, and
description of each program in the package.
For complete documentation, see the user guide that came with your HMMER distribution (Userguide.pdf); or see the HMMER web page
For additional information on copyright and licensing, see the file called COPYRIGHT in your HMMER source distribution, or see the HMMER
web page (@HMMER_URL@).
Janelia Farm Research Campus
19700 Helix Drive
Ashburn VA 20147 USA
@HMMER_VERSION@ @HMMER_DATE@ HMMER(1)