Dictionary of Protein Sites and Patterns
Release 2020_02, Apr 20
Swiss Institute of Bioinformatics
2,588 entries

Protein families database of alignments and HMMs
Release 32.0, Oct 18
The Pfam Consortium
17,772 entries

NCBI Conserved Domain Database
Release 3.18, Apr 20
National Center for Biotechnology Information
55,426 entries