EFI - Enzyme Similarity Tool

The UniProtKB database used by the EFI tools is undergoing major reorganization starting with the just-released version 2025_04 (https://www.uniprot.org/help/refprot_only_changes). When the reorganization is fully implemented (2026_02 release, Spring 2026), the number of proteins in UniProtKB will decrease from ~253M accessions in the previous 2025_03 release to ~141M accessions in the 2026_02 release.

In response to these changes, we will provide the previous 2025_03 release until the 2026_02 release is available.

The current 2025_04 release removed 82M UniProt IDs; the UniProt pages providing functional annotation for these IDs are no longer active. A new Metadata Tool provides access to the node attribute metadata for all UniProt IDs in the 2025_03 release that the tools continue to use during the UniProtKB reorganization. The Tool is available using the tab at the top of each page.

More information about the reorganization is located here.