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) 
>U20943|MH2-DB1*01|Oncorhynchus mykiss|F|EX1|splicing A|complete|
MSMPIAFYICLTLLWSIFSGT
>U20943|MH2-DB1*01|Oncorhynchus mykiss|F|EX2|splicing A|complete|
GYFEQVVRQCRYSSKDLHGIEFIDSYVFNKAEHVRFNSTVGRYVGYTEHGLKNAEAWNSD
AGILGQEQAELERYCKPSAAIDYSAILDKT
>U20943|MH2-DB1*01|Oncorhynchus mykiss|F|EX3|splicing A|complete|
EPHVRLSSVTPPSGRHPAMLMCSAYDFYPKQIRVTWLRDGREVKSDVTSTEELANGDWYY
QIHSHLEYTPKSGEKISCMVEHISLTEPMMYHW
>U20943|MH2-DB1*01|Oncorhynchus mykiss|F|EX4|splicing A|complete|
PSLPEAERNKIAIGASGLVLGTILALAGLIYYKKK
>U20943|MH2-DB1*01|Oncorhynchus mykiss|F|EX5|splicing A|complete|
SGVL
>U20943|MH2-DB1*01|Oncorhynchus mykiss|F|EX1-5|splicing A|complete|
MSMPIAFYICLTLLWSIFSGTDGYFEQVVRQCRYSSKDLHGIEFIDSYVFNKAEHVRFNS
TVGRYVGYTEHGLKNAEAWNSDAGILGQEQAELERYCKPSAAIDYSAILDKTVEPHVRLS
SVTPPSGRHPAMLMCSAYDFYPKQIRVTWLRDGREVKSDVTSTEELANGDWYYQIHSHLE
YTPKSGEKISCMVEHISLTEPMMYHWDPSLPEAERNKIAIGASGLVLGTILALAGLIYYK
KKSSGVL