NCBI has been asked to take over the ownership and maintenance of the TIGRFAM collection of Hidden Markov Models (HMMs), which is widely used for the annotation of prokaryotic genomes. The TIGRFAMs are a collection of curated protein families started in 1998 at The Institute of Genomic Research (TIGR), precursor to the J. Craig Venter Institute (JCVI). This collection is publicly available under a Creative Commons license and downloadable from NCBI. We have already made hundreds of improvements to TIGRFAM names and descriptions and we will continue to make regular updates.\
The TIGRFAM collection is one of four collections of HMMs used for structural and functional annotation in the Prokaryotic Genome Annotation Pipeline (PGAP), and for the continuous functional refinement of reference sequences in RefSeq (see Haft DH et al., 2018). Other HMM collections used by the PGAP project are Pfam, PRKfam derived from the NCBI PRK clusters and NCBIfam, a growing collection of models built to fill a variety of different needs in automated genome annotation.
TIGRFAMs and our other HMM libraries can be downloaded from the NCBI ftp site.