Protein family models used by PGAP are now available for download

A new release of the NCBI protein families profiles used by PGAP (the Prokaryotic Genome Annotation Pipeline) is now available. You can search this collection of Hidden Markov models (HMM) against your favorite prokaryotic proteins to identify their function using hmmer.

The HMMs are used as hints for the structural annotation of protein-coding genes in bacterial genomes and are also one of the sources for the names assigned to PGAP-annotated proteins presented in the Evidence-For-Name-Assignment comment block of RefSeq protein records (See for example, WP_004152100.1).

The collection comprises 12,753 HMMs that were built at NCBI, and 4,486 TIGRFAM HMMs whose ownership was transferred to NCBI in April 2018. In addition to the HMM profiles and seed alignments, a tab-delimited file containing the product names and other attributes added to the HMMs by curators is available.

  • 85% of models were assigned a product name that can be transferred to proteins hit by the model.
  • 7702 models have gene symbols.
  • 14508 are supported by a least one publication.
  • 6266 are assigned an Enzyme Commission number.
  • 617 represent anti-microbial resistance proteins.
  • Product names added to 4,686 PFAM HMMs owned by EBI-EMBL and used for functional annotation by PGAP are also included.

A total of 57 million RefSeq prokaryotic proteins have been named based on these curated HMMs, and can be identified with the Entrez query “meta Evidence-For-Name-Assignment”[Properties]¬†AND “Evidence Category=HMM”[Text Word]. See an example and more information on web displays of HMMs in a previous post.

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