What is PROSITE?

PROSITE is a database of protein families and domains. It is based on the observation that, while there is a huge number of different proteins, most of them can be grouped, on the basis of similarities in their sequences, into a limited number of families. Proteins or protein domains belonging to a particular family generally share functional attributes and are derived from a common ancestor.

It is apparent, when studying protein sequence families, that some regions have been better conserved than others during evolution. These regions are generally important for the function of a protein and/or for the maintenance of its three- dimensional structure. By analyzing the constant and variable properties of such groups of similar sequences, it is possible to derive a signature for a protein family or domain, which distinguishes its members from all other unrelated proteins. A pertinent analogy is the use of fingerprints by the police for identification purposes. A fingerprint is generally sufficient to identify a given individual. Similarly, a protein signature can be used to assign a newly sequenced protein to a specific family of proteins and thus to formulate hypotheses about its function.

PROSITE currently contains patterns and profiles specific for more than a thousand protein families or domains. Each of these signatures comes with documentation providing background information on the structure and function of these proteins.

Click here to see a sample entry.

Update frequency

The PROSITE release is concurrent with every release of UniProtKB, which takes place every 8 weeks. New families and domains are added in each release, and existing families and domains are periodically updated.


PROSITE is copyrighted by the SIB Swiss Institute of Bioinformatics and distributed under the Creative Commons Attribution-NonCommercial-NoDerivatives (CC BY-NC-ND 4.0) License, see PROSITE license conditions.

How to cite

If you use PROSITE, please cite:
"New and continuing developments at PROSITE" Nucleic Acids Res. 41: D344–D347(2012).

The list of all our publications can be found here.


PROSITE activities at the SIB are supported by the Swiss Federal Department of Economic Affairs, Education and Research through the State Secretariat for Education, Research and Innovation (SERI) .