Dictionary of Protein Sites and Patterns
Release 2018_06, Jun 18
Swiss Institute of Bioinformatics
2,527 entries

Protein families database of alignments and HMMs
Release 31.0, Mar 17
The Pfam Consortium
16,479 entries

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