The original TIGRFAMs database was a research project of the J. Craig Venter Institute (JCVI). TIGRFAMs, short for The Institute for Genomic Research's database of protein families, is a collection of manually curated protein families focusing primarily on prokaryotic sequences. It consists of hidden Markov models (HMMs), multiple sequence alignments, Gene Ontology (GO) terminology, Enzyme Commission (EC) numbers, gene symbols, protein family names, descriptive text, cross-references to related models in TIGRFAMs and other databases, and pointers to literature.

The TIGRFAMs database was transferred in April 2018 to the National Center for Biotechnology Information (NCBI), which now holds the creative commons license to this data and is responsible for maintaining and distributing this intellectual property. NCBI will redistribute TIGRFAMs using a data interchange format that allows the original source to submit new data for inclusion in future releases, should they wish to.

Data availabilty

Release 15.0 (4488 families, September 16 2014), the most recent version of the TIGRFAMS, is now hosted on the NCBI FTP site along with other HMM collections. It continues to be available from the J. Craig Venter Institute.

TIGRFAMs data are made available under a Creative Commons Attribution-ShareAlike 4.0 license. A brief summary and full text of the license are available at Creative Commons


Haft DH, Loftus BJ, Richardson DL, Yang F, Eisen JA, Paulsen IT, White O. TIGRFAMs: a protein family resource for the functional identification of proteins. Nucleic Acids Res. 2001 Jan 1;29(1):41-3. PMID: 11125044

Haft DH, Selengut JD, White O. The TIGRFAMs database of protein families. Nucleic Acids Res. 2003 Jan 1;31(1):371-3. PMID: 12520025

Selengut JD, Haft DH, Davidsen T, Ganapathy A, Gwinn-Giglio M, Nelson WC, Richter AR, White O. TIGRFAMs and Genome Properties: tools for the assignment of molecular function and biological process in prokaryotic genomes. Nucleic Acids Res. 2007 Jan;35(Database issue):D260-4. Epub 2006 Dec 6. PMID: 17151080

Haft DH, Selengut JD, Richter RA, Harkins D, Basu MK, Beck E. TIGRFAMs and Genome Properties in 2013. Nucleic Acids Res. 2013 Jan;41(Database issue):D387-95. doi: 10.1093/nar/gks1234. Epub 2012 Nov 28. PMID: 23197656

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Last updated: 2018-07-06T18:53:13Z