EFI - Enzyme Similarity Tool

With the current 2026_02 release, the UniProtKB database is reorganized to include an expanded number of Reference Proteomes to better capture biodiversity. This includes the removal of proteins from taxonomically unclassified organisms, i.e., those without a binomial species name (genus and species). The total number of accessions in UniProtKB has been reduced from 253,635,358 in the “legacy” 2025_03 release to 149,810,139 in the current 2026_02 release.

We are providing the option to select either the “legacy” 2025_03 database or the current UniProtKB database (now 2026_02) when generating SSNs. You can select the database in the “Database” accordion on the pages for the EFI-EST options, the EFI-GNT tool, and the Taxonomy Tool. We suggest that you compare the SSNs, GNNs, and GNDs generated from both databases as you explore the information you are seeking.

The EFI Tools are being upgraded on 10/21/26. While the updated site is functionally identical to the old site, jobs run prior to that date will only be available through the results link in the finalization email (not the Previous Jobs tab). User accounts created on the old site will no longer be available, and users are encouraged to create new accounts when the upgraded site becomes available.