The aligned protein sequences and their families from Pfam:
ftp://ftp.ebi.ac.uk/pub/databases/Pfam/releases/Pfam32.0/Pfam-A.seed.gz

Stockholm format is a multiple sequence alignment format used by Pfam.
See: https://en.wikipedia.org/wiki/Stockholm_format

Attribute description:
- sequence: amino acid sequence (corresponding to a domain)
- sequencename: UniProtID/start-end position of the domain
- family_id: short name of the protein family
- family_accession: PFam family identifier (PFxxxxx.y)
- aligned_sequence: single sequence from the multiple sequence alignment
                    (with the rest of the members of the family in seed),
                    with gaps retained.