Predicted protein sequence of the murine I-E-beta S-polypeptide chain from cDNA and genomic clones

Ia antigens are polymorphic cell-surface glycoprotein complexes, encoded within the I region of the mouse major histocompatibility complex, that control the ability of the organism to mount effective antigen-specific immune responses. We have isolated and determined the nucleotide sequences of cDNA and genomic clones for the I-E beta s gene and we present the predicted protein sequence for most of the E beta s polypeptide chain. The E beta s polypeptide shows 95% protein homology to the other cloned E beta alleles. Comparison of the protein sequences of five E beta alleles from haplotypes that differ in responder phenotype to pigeon cytochrome c suggests that the structure of one of the E beta hypervariable regions may determine responsiveness to this antigen.