Dictionary of Protein Sites and Patterns
Release 2018_09, Oct 18
Swiss Institute of Bioinformatics
2,537 entries

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

NCBI Conserved Domain Database
Release 3.16, Apr 17
National Center for Biotechnology Information
50,369 entries