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IMGT reference sequences in FASTA format:

Amino acid sequences with gaps

The FASTA header contains:
IMGT accession number | gene and allele name | species | functionality | exon name | domain name | domain type | alternative splicing (if it is) | partial (if it is) 
>CQ789650|VSIG4*01|Mus musculus|F|EX1|
MEISSGLLFLGHLIVLTY
>CQ789650|VSIG4*01|Mus musculus|F|EX2|[D1]|V-LIKE|
GHPTLKTPESVTGTWKGDVKIQCIYDPLR......GYRQVLVKWLVRHGSDSVTIFLRDS
........TGDHIQQAKYRGRLKVSHKVPGDVSLQINTLQMDDRNHYTCEVTWQTPDGNQ
VIRDKIIELRVRK
>CQ789650|VSIG4*01|Mus musculus|F|EX3|
YNPPRINTEAPTTLHSSLE
>CQ789650|VSIG4*01|Mus musculus|F|EX4|
ATTIMSSTSDLTTNGTGKLEETIAGS
>CQ789650|VSIG4*01|Mus musculus|F|EX5|
GRNLPIFAIIFIISLCCIVAVTIPYILFRCRTFQQ
>CQ789650|VSIG4*01|Mus musculus|F|EX6|
EYVYGVS
>CQ789650|VSIG4*01|Mus musculus|F|EX7|
RVFARKTSNSEETTRVTTIATDEPDSQALISDYSDDPCLSQEYQITIRSTMSIPAC