This database contains 38,880 PHROGs (protein orthologous groups) containing 868,340 proteins from complete genomes of viruses infecting bacteria or archaea (2,318 from RefSeq and 2,669 from GenBank, april 2018), in addition to 12,498 curated prophages derived from cultivated microbial isolates (Roux et al., 2015).
only one standardized annotation was attributed to each PHROG (using RefSeq annotations, and comparison of each PHROG to Pfam, UNIPROT, KEGG and the ACLAME database)
This website provides access to :

• all prokaryotic virus genomes from the viruses table and select one to see its taxonomy, list of proteins, genomic map, etc...
• all PHROGs from the PHROGs table and select one to see its annotation, list of proteins, multiple alignment, comparison results to Pfam, Uniprot, KEGG, etc...

Viruses and PHROGs can also be access using search tools below.

    If you don't know the accession of your virus, use the search box below :

    If you have a protein from the NCBI and you wish to know if it belongs to a PHROG, you can search it by its sequence or its NCBI ID.

! Each of these zipped archive files (.tar.gz) contains 38,880 files (one fasta file, one MSA and HMM profile for each PHROG).
The current release is version 4 of PHROGs annotations, take a look at the News page for more information.

Out of the initial set of 938,864, a subset of 70,524 proteins were not grouped with other proteins into PHROG and remained singletons (or ORFans). You can also download these singleton protein as a single fasta file : Fasta files (Singletons)

Check out the manual on the Documentation page to compare your proteins to PHROGs.