title: DNA sequence of the gene encoding the E alpha Ia polypeptide of the BALB/c mouse.
abstract: A 3.4-kilobase DNA fragment containing the gene coding for the E alpha chain of an Ia (I region-associated) antigen from the BALB/c mouse has been sequenced. It contains at least three exons, which correlate with the major structural domains of the E alpha chain-the two external domains alpha 1 and alpha 2, and the transmembrane-cytoplasmic domain. The coding sequence of the mouse E alpha gene shows striking homology to its counterpart at the DNA and protein levels. The translated alpha 2 exon demonstrates significant similarity to beta 2-microglobulin, to immunoglobulin constant region domains, and to certain domains of transplantation antigens. These observations and those of others suggest that the Ia antigen, transplantation antigen, and immunoglobulin gene families share a common ancestor.
mesh_terms: D000818:Animals; D001483:Base Sequence; D005075:Biological Evolution; D005796:Genes; D005802:Genes, MHC Class II; D046911:Macromolecular Substances; D051379:Mice; D008807:Mice, Inbred BALB C / Q000235:genetics*; D001613:beta 2-Microglobulin / Q000235:genetics
chemical_list: D046911:Macromolecular Substances; D001613:beta 2-Microglobulin