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IMGT reference sequences in FASTA format:

Amino acid sequences without 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) 
>J03857|CD79B*01|Mus musculus|F|EX1|
MATLVLSSMPCHWLLFLLLLFS
>J03857|CD79B*01|Mus musculus|F|EX2|
GEPVPAMTSSDLPLNFQ
>J03857|CD79B*01|Mus musculus|F|EX3|[D]|C-LIKE|
GSPCSQIWQHPRFAAKKRSSMVKFHCYTNHSGALTWFRKRGSQQPQELVSEEGRIVQTQN
GSVYTLTIQNIQYEDNGIYFCKQKCDSANHNVTDSCGTELLVL
>J03857|CD79B*01|Mus musculus|F|EX4|
GFSTLDQLKRRNTLKDGIILIQTLLIILFIIVPIFLLLDK
>J03857|CD79B*01|Mus musculus|F|EX5|
DDGKAGMEEDHTYE
>J03857|CD79B*01|Mus musculus|F|EX6|
GLNIDQTATYEDIVTLRTGEVKWSVGEHPGQE
>CD79B*01|Mus musculus|F|EX1-6|Complete|Splicing A|
MATLVLSSMPCHWLLFLLLLFSGEPVPAMTSSDLPLNFQGSPCSQIWQHPRFAAKKRSSM
VKFHCYTNHSGALTWFRKRGSQQPQELVSEEGRIVQTQNGSVYTLTIQNIQYEDNGIYFC
KQKCDSANHNVTDSCGTELLVLGFSTLDQLKRRNTLKDGIILIQTLLIILFIIVPIFLLL
DKDDGKAGMEEDHTYEGLNIDQTATYEDIVTLRTGEVKWSVGEHPGQE*