NEW: download a virtual machine to run virfam and read here how to open the virtual machine


Welcome to VIRFAM !


VIRFAM is dedicated to the recognition of head-neck-tail modules and of recombinase genes in phage genomes.

You can use this server to search for remote homologs of specific protein families within protein sequences of bacteriophages. The process of one sequence, including profile generation and database scanning may last up to 5 minutes each. Please provide your email below to be kept informed.

1. Select type of analysis
2. Protein Sequences to analyze

Search the database of 1071 pre-computed bacteriophage genomes by names or keywords (example output) and analyze to which category of head-neck-tail module it belongs.
    or browse the whole database

In case your bacteriophage is not already in the database, you can analyze whether its genome can be assigned to one of the defined categories:

Simply copy-paste your protein sequences (not DNA) or upload a sequences file in fasta format.
   - Warning : The order of the genes is important since it is used to define the genetic context.
   - If your bacteriophage genome is available at the NCBI, ordered protein sequences can be obtained with seqviewer (see how to proceed).

Query name :
Sequences :
 (FASTA format only) 

or upload file :
3. Getting results
Enter a valid e-mail address where we can send a link to the results when the run is completed.
E-mail :   


If you find this site useful, please cite :

For recombinase search:
Lopes A, Amarir J, Faure G, Petit M-A, Guerois R. Detection of novel recombinases in bacteriophage genomes unveils Rad52, Rad51 and Gp2.5 remote homologs. Nucleic Acids Res. (2010) 38(12):3952-62.Pubmed

For Head-Neck-Tail analysis:
Lopes A, Tavares P, Petit MA, Guérois R, Zinn-Justin S. Automated classification of tailed bacteriophages according to their neck organization. BMC Genomics. (2014) 15:1027. doi: 10.1186/1471-2164-15-1027.